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淺村 峻
1991 年 77 巻 7 号 p.
861-870
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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増子 昇
1991 年 77 巻 7 号 p.
871-877
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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塩原 幸光, 岡戸 昭佳, 阿部 雅樹, 鷺山 勝
1991 年 77 巻 7 号 p.
878-885
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
シリカゾルを含有する硫酸浴ベースのZn-シリカ分散めっき浴に硝酸ナトリウムを添加することにより,シリカ粒子のめっき皮膜中の析出効率は向上する.本研究では主としてめっき液の性状,めっきの析出挙動およびめっき皮膜の微細構造について調査した.得られた結果を以下に要約する.
1)めっき液中のシリカ粒子の分散性は良好で沈殿の発生はない.シリカ粒子は経時凝集する傾向が見られるが,低pH域(pH1.5~2.0)で比較的安定である.
2)シリカ粒子の析出に必要な硝酸ナトリウムの濃度は主としてめっき液のpHに依存し,低pHほど硝酸ナトリウムの必要量は高い.
3)めっき液中のシリカ濃度が高いほど,また電流密度は低いほどめっき皮膜中へのシリカ共析率は増加する.
4)表層を除き,めっき皮膜中のシリカ粒子分布は均一である.表層にはシリカ凝集層と考えられる薄いシリカリッチ層が存在する.表層部を含むめっき皮膜には金属Zn,シリカ粒子のほかに微量の酸化状態のZnが含まれる.この酸化状態のZnはシリカ粒子上に吸着して析出したZn(OH)
2であると考えられる.
5)シリカ粒子の析出メカニズムとして,硝酸イオンの還元によるカソード界面pHの上昇→カソード表面上でのシリカ粒子の凝集・粒子表面へのZn(OH)
2吸着→析出という析出過程が考えられる.
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近藤 和夫
1991 年 77 巻 7 号 p.
886-891
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Zinc-nickel electrodeposited sheet steels have widely been adopted for automobile bodies for their improvements in the corrosion resistance and formability. In principle, these properties depend on the crystal structure, morphology and microstructure of deposits. The deposits of various zinc contents have been prepared galvanostatically from sulfate baths and examined by scanning and transmission electron microscopies. The 96.8 at% zinc, η-single phase deposit exhibits a collective morphology of hexagonal plates thin in the direction of
c-axis. With the decrease of zinc content, the deposit changes to the hexagonal columnar crystals which have triangular pyramidal shape in morphology. These hexagonal columnar crystals are formed by the lateral growth of the hexagonal plate edge i.e. step along (00·1)
η side surfaces. The 92.7 at% zinc hexagonal columnar crystals form steps on {10·0}
η surfaces, and flatten the steps on {10·0}
η surfaces with the decrease of zinc content. Further decrease of zinc content to 88.4 at% zinc, the hexagonal columnar crystals can no more absorb γ-particles. These excess γ-particles form granular crystals, and precipitate between the hexagonal columnar crystals.
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関 彰, 亀井 一人
1991 年 77 巻 7 号 p.
892-897
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The crystallographic aspects of zinc and zinc-nickel alloy electrodeposits on steel sheets have been studied by means of transmission electron microscopy (TEM) and O-lattice theory. TEM observation shows that the pure zinc and zinc-nickel hcp η-phase electrodeposits grow epitaxially on α-iron substrate with Burgers' orientation relationship. O-lattice theory predicts this relationship for η-phase while the increase of Ni content changes the dimensions of a-axis and c-axis. TEM observation shows the cube-cube parallel relationship between the zinc-nickel γ-phase and the substrate. This relationship can be also interpreted in terms of O-lattice theory.
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和氣 亮介, 吉原 良一, 兼田 善弘, 山本 正弘
1991 年 77 巻 7 号 p.
898-905
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The alloy plating method by the thermal diffusion was developed in order to get the Ni-Sn-Zn alloy plated steel. This new method consists of two processes, at first, Ni, Sn and Zn triple layers are electroplated on the steel in this order and then, the electroplated layers are heated for the diffusion. The structure of this Ni-Sn-Zn alloy consists of the multi-component alloy layers, the surface side consists of Sn-Zn eutectic alloy and the steel base side consists of Zn-Ni and Sn-Ni alloys. The diffused multi-alloy layers on the steel have some interesting properties, such as a good corrosion resistance in the salt spray test and the humidity test, an excellent solderability and the suppression for the occurrence of tin whiskers. Therefore, this thermal-diffused Ni-Sn-Zn alloy coated steel sheets (Ni=0.4, Sn=3.0, Zn=0.5 g/m
2) are commercially used for the components of electric appliances.
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市島 真司, 溝部 孝志, 神田 勝美
1991 年 77 巻 7 号 p.
906-912
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
Electroplating in dilute Ni
2+ electrolyte over limiting current density has been investigated as the blackening method for the electrogalvanized steel sheet.
The structure of the black deposits on the electrogalvanized steel sheet was analyzed by the X-ray diffraction method, scanning electron microscope, X-ray photoelectron spectrometer and glow discharge spectrometer and it was found that the surface of the black electrogalvanized steel sheet was partly covered with small Ni granules of about 0.1 μm in diameter.
The small Ni granules were covered with Ni, Zn, and composite compounds, such as Ni (OH)
2, NiO, Ni
2O
3, Zn(OH)
2 or ZnO and further covered with Zn(OH)
2, ZnO of around 100 Å thick.
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碓井 建夫, 川端 弘俊, 松原 茂雄, 深作 博史, 水谷 健, 森田 善一郎
1991 年 77 巻 7 号 p.
913-920
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Effect of pulsating flow on mass transfer in packed bed is studied by taking Fe
3+-iron particle system as an example of liquid-solid system, because of the industrial importance of iron plating. Spherical and cubic particles are used as packing materials having very different shapes. Pulsation is generated by a rotary cock or a piston.
Mass transfer coefficient
kL for cubes under steady flow is larger than that for spheres. Comparison of
kL under steady and pulsating flow without reverse flow (rotary cock) shows no effect of pulsating flow on mass transfer for both spheres and cubes. Comparison of
kL under steady and pulsating flow with reverse flow (piston) reveals, however, excellent effect; mass transfer for spheres is accelerated under quasisteady state and that for cubes is promoted much more than in quasi-steady state, where mass transfer is assumed to proceed depending on the absolute value of velocity.
Velocity fluctuations just after the bed are measured by a hot film probe and the difference between the flow fields for spheres and cubes is discussed in connection with the difference of the mass transfer under steady and pulsating flow.
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高橋 節子, 小浦 延幸
1991 年 77 巻 7 号 p.
921-930
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
新しい表面処理の分野として,非水めっきを取り上げ,研究例の紹介から今後の展望まで述べてみた.周期表の1~8までめっきの可能性は示されているが,実用化に近づいているのはAl系のめっきだけである.非水めっきの普及にはかなり時間を要するとも考えられるが,これまで電気めっきとして不可能であった金属のめっきが可能となることを考えると,この分野の研究にもっと力が注がれるべきであろう.
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内田 淳一, 津田 哲明, 山本 康博, 瀬戸 宏久, 阿部 賢, 澁谷 敦義
1991 年 77 巻 7 号 p.
931-938
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Although molten salt electroplating is interesting method to develop new pre-coated steels, there has been little commercial exploitation because of powdery and/or dendritic deposits. In this study, the electroplating of Al, especially Al-Mn alloy on steel sheet in AlCl
3-NaCl-KCl molten salt bath is focused. High speed fluid flow of molten salt and deposition of Al-Mn alloy were found to be most effective to smooth-faced deposition at high current density. Consequently, ultra-smooth lustrous deposit with amorphous structure was generated.
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福居 康, 甲田 満, 広瀬 祐輔
1991 年 77 巻 7 号 p.
939-946
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Spangles formed at hot-dip galvanized steel were classified and the distribution of Pb and Al, which were impurity and additional element respectively in molten zinc bath, on the spangle surface was investigated. The hot-dip galvanized Al-killed steel was produced with gas reduction type hot dipping testing aparatus in which steel sheet was cleaned by heating in reducing atmosphere and dipped into molten zinc bath which contained 0.25 wt%Pb and 0.17 wt%Al. X-ray Laue method was used for determination of crystal orientation and EPMA was used for the measurement of distribution of Pb and Al at the spangles.
The main results of the study are follows:
(1) The spangles are classified from the point of view of the crystal orientation and the appearance into the seven types as follows,
Fern I, Fern II, Mirror, Frost, Half fern, Feather, Triangle.
(2) The direction of the straight boundary of the spangles coincide with the projected direction of preferred crystal growth orientation (<1010>) on the spangle surface.
(3) Spangles are classified into α type and β type from the point of view of the inclination of c-axis (<0001>). The c-axis of α type spangle is inclined to the straight boundary of the spangles and the c-axis of β type spangle is inclined to the reverse direction.
(4) The amounts of Pb and Al at the spangle surface vary with the types of the spangle.
(5) The spangle with the larger amounts of Pb and Al has less brilliance.
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斎藤 実, 内田 幸夫, 橘高 敏晴, 広瀬 祐輔, 久松 敬弘
1991 年 77 巻 7 号 p.
947-954
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The formation behavior of the alloy layer in the initial stages of galvanizing at 450°C has been investigated, using ultra low carbon Ti added steel sheet. The formation of Fe-Zn intermetallic compounds on the steel surface was retarded with the increase of Al content in galvanizing bath. For high Al content in the bath, Fe
2Al
5 intermetallic compound grew with dipping time. At the same time, diffusion of Zn into Fe
2Al
5 layer occurred. And furthermore, the outburst phenomenon was observed with the increase of immersion. The occurrence site of outburst structure corresponded well to grain boundary of the base steel. Fe
2Al
5 layer formed in the first step of immersion was fractured by the occurrence of outburst and dispersed in zinc coating. The formation mechanism of the outburst structure which means the initiation of growth of Fe-Zn intermetallic compounds was discussed.
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中森 俊夫, 澁谷 敦義
1991 年 77 巻 7 号 p.
955-962
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
A mathematical technique has been suggested to estimate more adequate isothermal alloying behaviortime and temperature dependence of Fe enrichment-in galvanized coating in galvannealing process. Galvannealing experiments using salt-bath were conducted with mill products of galvanized steel; and Austin-Ricketts' type equations were applied to data-fitting by means of multiple regression analysis so as to linearize the relation of Fe quantity in coating and heating time.
The original experimental equations, which involve errors due to unavoidable heating-up periods in heattreatment in salt-bath were adjusted to more adequate ones by applying finite difference approximation and multiple regression analysis repeatedly and alternately.
It was proved through correlation between estimated values and observed ones that the adjusted equations are more appropriate than the original ones. Corrected log (Fe quantity in coating)
vs. log(
t) plots indicated the following: 1) Fe enriching behavior at 450°C is subject to the reverselogarithmic time dependence at the outset of the reaction, and to auto-catalytic time dependence after some latent time. 2)The behavior at 500°C and higher temperatures is subject to the parabolic time dependence.
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中森 俊夫, 坂根 正, 須藤 忠三, 澁谷 敦義
1991 年 77 巻 7 号 p.
963-970
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Anti-exfoliation properties of galvannealed coatings on extra low carbon Ti-added steel galvannealed under various heating conditions were investigated by using a bead-drawing test, and the result was compared with that of a cylindrical cupping test and an adhesive-bonding tensile test.
Exfoliation amounts in the bead-drawing test are not necessarily correlated with those in the cupping test: regarding ζ-rich coatings, significant discrepancy between exfoliation amounts in the bead-drawing test and those of the cupping test was observed, and exfoliation amounts in the bead drawing test were larger than expected values deduced from the result in the cupping test. ζ-rich coatings are subject to coating exfoliation at coating/steel boundary in the bead drawing test as well as in the adhesive-bonding tensile test. It was thought that the deterioration of exfoliation resistance of ζ-rich coatings is attributable to high frictional coefficient and relatively poor coating adhesion at coating/steel boundary. Coating adhesion of ζ-rich coatings to steel substrate is improved by eliminating ζ-phase by means of galvannealing at temperatures below 500°C.
Coating adhesion of δ
1-rich ones galvannealed above 550°C was proved very poor in both the bead-drawing test and the cupping test; in both cases, exfoliation of this type coatings seems to be caused by bending-unbending deformation.
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浦井 正章, 有村 光史, 寺田 誠, 山口 雅彦, 堺 裕彦, 野村 伸吾
1991 年 77 巻 7 号 p.
971-978
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The effects of various manufacturing conditions on powdering characteristics were investigated. Powdering is suppressed by an increase in Al content of the bath, a decrease in the bath temperature and a decrease in the galvannealing temperature. All of these conditions tend to delay the alloying progress. In the case of low Al content (0.12%), ζ-phase (FeZn
13) abruptly, appears and forms homogeneous layer at the initial stage of alloying, and then completely changes into δ
1-phase (FeZn
7) in a short period. When the Al content is high (0.16%), the alloying progress is slow and ζ-phase appears heterogeneously at localized spots with time lags. The ζ-phase which appeared late remains unchanged up to the δ
1-phase. As the hardness of ζ-phase is lower than that of δ
1-phase, the ζ-phase deforms preferentially and relaxes a part of stress induced by forming, therefore powdering is suppressed.
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櫻井 理孝, 張 力偉, 田尻 泰久, 近藤 隆明
1991 年 77 巻 7 号 p.
979-986
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
Effect of coating structure on powdering resistance of galvannealed steel sheet was investigated and the followings are clarified.
1)Higher galvannealing temperature deteriorates powdering resistance. But slower cooling from higher temperature (500550°C) improves powdering resistance.
2)In the case of lower galvannealing temperature (=440°C), the powdering resistance is rather good, although the cooling rate doesn't affect powdering resistance.
3)Exfoliation of galvannealed steel sheet after tensile test correlates with amount of powdering evaluated from draw bead test.
4)
Γ1-phase (Fe
5Zn
21) is formed along the interface of coating galvannealed at lower temperature (≤500°C) or cooled slowly from high galvannealing temperature.
5)The decrease of
Γ1 ratio [
Γ1/(
Γ+
Γ1)] deteriorates powdering resistance.
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細見 和昭, 斎藤 実, 橘高 敏晴, 広瀬 祐輔
1991 年 77 巻 7 号 p.
987-994
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
As an alternative to the Non Oxidizing Furnace (NOF) method, the subject of a continuous heating process for annealing and surface activation of steel sheets prior to vapor zinc coating was taken up.
Studies on a laboratory-scale were made up to find out whether production of vapor zinc coated steel sheets with excellent adhesion was possible in a N
2 atmospheric gas with limited amount of H
2 content using the conventional continuous annealing furnace. As the result, it was found that production of vapor zinc coated steel sheets with superior performance was possible even by the continuous annealing conditions of [700°C×45 s annealing→400°C×240 s overaging] at base steel temperature just before vapor zinc coating of 150°C and above, if O
2 concentration was less than 2.5×10
-3 vol% in the 2 vol%H
2-H
2 gas with dew point of -20°C.
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川福 純司, 加藤 淳, 外山 雅雄, 西本 英敏, 池田 貢基, 佐藤 廣士
1991 年 77 巻 7 号 p.
995-1002
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
従来の電気めっき法,溶融めっき法に代わる新しいめっき法として,EB加熱方式による真空蒸着法を応用した連続蒸着試験設備により,5種類の蒸着Zn合金めっき鋼板を作製した.その結果,以下のことが明らかとなった.
1)電子ビーム加熱により,近接された二つのるつぼから,Znと合金元素を同時蒸発させることによって,連続的に鋼板表面に蒸着Zn合金めっき層を形成することが可能である.
合金めっきのめっき付着量及びめっき組成の制御は,電子ビームの出力,照射時間配分及びラインスピードを調整することによって可能である.
2)めっき層の表面結晶状態は,合金元素の種類によって異なり,六方晶の結晶が基板に対して平行に配向するものと,斜めに配向するものとに大別された.ただし,蒸着Zn-Ni合金めっきについては,明確な結晶粒が認められなかった.
3)めっき深さ方向の合金組成のプロフィールについても,合金元素の種類によって異なり,Znと合金元素のプロフィールがほぼ均一な構造を有する場合と,2層に近い構造を有する場合とがある.
4)Znと合金元素とによってめっき層中に得られる金層間化合物相は,合金元素がAlの場合を除き,平衡状態図から想定される相がほとんど存在しない.これは,本真空蒸着法によって得られる蒸着Zn合金めっき層の形成過程が,非平衡に近い状態で進行するためと考えられる.
5)今回作成した蒸着Zn合金めっきの中では,Zr-Mg合金めっきとZn-Ti合金めっきが優れた裸耐食性を示した.
また,塩水噴霧試験による蒸着Zr-Mg合金めっきの腐食生成物層は,六方晶の底面が基板に対して配向したZnCl
2・4Zn(OH)
2から形成されていることが明らかとなった.
蒸着Zr-Mg合金めっきの裸耐食性は,腐食生成物層によるめっき層の保護作用によるものと考えられ,めっき層中から溶解したMgイオンは,このような腐食生成物層を維持し続ける働きを有するものと推察される.
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安江 良彦, 木部 洋, 兵藤 知明, 影近 博
1991 年 77 巻 7 号 p.
1003-1010
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Effects of pretreatments such as argon ion bombardment and preheating of steel substrates on adhesion and formability of ion plated films were studied. The chromium film formed on the steel substrate with preheating at 200°C and argon ion bombardment (proper pretreatment) provided the excellent adhesion and formability compared with that formed without preheating or argon ion bombardment. The compositional depth profiles of chromium films on steels obtained by AES showed that the chromium film formed on the steel pretreated properly had no oxide and carbonaceous contamination at the interface, with much broader mixing zone than that of the chromium film formed without argon ion bombardment or preheating. It was suggested that the good adhesion of the chromium film formed on the steel with proper pretreatment was attributed to both the sputter cleaning effect before deposition and the formation of mixing zone.
The growth and orientation of the chromium films formed on the steels with various pretreatments were investigated using TEM. Plate-like grains grew epitaxially on the steel with proper pretreatment, whereas very small grains that didn't grow epitaxially were observed in the films formed with improper pretreatment. It was considered that the inferior formability of the chromium film formed without argon ion bombardment or preheating was caused by the high probability of the crack formation in grain boundaries among many small grains.
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河村 宏明, 加隈 徳昭, 武居 芳樹, 吉岡 治
1991 年 77 巻 7 号 p.
1011-1018
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Granular tin was plated on steel prior to chromate treatment.
The granular tin plating was obtained by extremely low current density electrolysis or by reducing the concentration of additional tin plate.
The dispersedly plated granular tin improved the weldability for sanitary can production because of its lower electric contact resistance, and gave a good corrosion resistance because of its cathodic protection action to steel in comparison with the conventional Tin Free Steel.
Suitable covering area of the dispersedly plated granular tin on steel substrate was found to be 1570%.
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田中 厚夫, 中川 泰彦, 英 哲広
1991 年 77 巻 7 号 p.
1019-1025
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The formability of thermosetting epoxy phenolic lacquer film painted on tin coated steel sheets (TP) and chromium coated steel sheets (TFS) both with chromium oxide layer was evaluated by electric resistance of the painted steel sheets and observation of SEM. The formability of the lacquer film on TFS becomes worse with increasing coating weight of chromium, while in the case of TP, the formability improves with increasing coating weight of tin. It is considered that the formability of plating layer apparently influences the formability of the film on the plating.
The corrosion resistance of the painted steel sheets in acetic acid aqueous solution was evaluated by measuring the electric resistance of the sheets. The electric resistance of the painted TFS, which is low compared with that of painted TP, decreases rapidly in the solution, while that of painted TP decreases gradually.
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加藤 千昭, 飛山 洋一, 安田 顕, 大和 康二
1991 年 77 巻 7 号 p.
1026-1033
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
It is important to study the effect of the Ni content on phosphatability of Zn-Ni alloy electroplated steel sheets which are used in the exposed side of automotive bodies. Phosphate coating weights formed on pure Zn and Zn-Ni alloy containing Ni above 11.5% are independent of zinc phoshate solution flow rates and uniform coatings can be obtained. The alloys containing 3 to 9% Ni, however, show a strong flow rate dependency. A number of zinc phosphate crystal nuclei decreases and the final coating weight increases with a decrease in the flow rate. These alloys may cause trouble in the coating uniformity when they are used in the antomotive phosphating line where the flow rate is not uniform.
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福本 博光, 水木 久光, 増原 憲一
1991 年 77 巻 7 号 p.
1034-1041
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
亜鉛めっき鋼板といっても,めっき方法が異なると,表面の酸化皮膜の組成・構造が異なり,塗布型クロメート処理前にどの程度酸化皮膜をエッチングすればよいかが重要なKnow howとなる.これまでは,エッチング減量,Co・Feなどの析出量,クロメート皮膜量およびクロメート皮膜中のCr濃度などを測定するとともに,種々の条件で表面調整処理を施した試料に塗布型クロメート処理を施し,塗装した後,塗膜密着性,耐食性などの確性試験をして評価してきた.
本報では,表面調整-短時間クロメート処理前後の表面に発生する腐食電流を200ppmCl
-溶液中で走査型振動電極装置により測定し,得られた電位差分布図と,塗装後の塗膜密着性および腐食性との関係を比較検討した.そして,次のような結果が得られ,走査型振動電極法が,塗装前処理の特に表面調整処理の適性を評価する方法として適用可能であることがわかった.
(1)亜鉛めっき鋼板の場合,塗布型クロメート処理前の表面状態として,短時間クロメート処理後の表面からアノード電流が検出されないように表面調整処理を選定することにより,塗膜密着性が良好で,耐食性に優れた塗装鋼板が得られた.
(2)すなわち,溶融Znめっき鋼板では,6s表面調整処理を施した後に,所定の塗布型クロメート処理を施すこと,また,蒸着Znめっき鋼板では,表面調整処理を施さずに所定の塗布型クロメート処理を施すことが,塗装前処理として最適な条件であるといえる.
(3)短時間クロメート処理後のSVETによる腐食電流測定結果と,所定の塗布型クロメート処理をした塗装鋼板の切断端面部の耐食性とが良い対応を示した。これは,塗布型クロメート処理の初期段階の反応が,均一なクロメート皮膜形成を左右していることを示すものと推察された.
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須田 新, 荻野 陸雄, 田中 成夫
1991 年 77 巻 7 号 p.
1042-1049
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Influence of drying temperature on states and physical properties of a dry-in-place type chromate coating which contains Cr (III), Cr (VI), and PO
43- were investigated by thermal analysis method. And also the relationship between thermal states and corrosion resistance was studied.
The result of the differential thermal analysis method with the chromate coating at wide range of temperature shows characteristics reactions of inorganic materials.
Endothermic reaction at a range from 85°C till 200°C and exothermic reaction from 200°C till 300°C were found. The chromate coating can be divided into three states from the result of this thermal behavior.
The result of corrosion test of this chromate coated galvanized steel between visual and electrochemical method exhibits the best performance with drying at the end temperature of the endothermic reaction.
It was also proved by values of chromium fixed ratio in coating that chromate coating had several thermal states and exhibited different physical properties as adhesion strength etc.
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金丸 辰也, 河上 毅, 田中 修二, 新井 勝利, 山本 満治, 水野 薫
1991 年 77 巻 7 号 p.
1050-1057
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The structure of phosphate crystals that exerts a favorable effect on the scab corrosion resistance on the painted steel surface was investigated and characterized by 1) a low Zn/P intensity ratio measured by glow discharge spectrometry, 2) a low preferred orientation of the (100) plane in phosphophyllite, and 3) angular and granular phosphate crystal morphology.
The aforementioned structure of phosphate crystals depends on the crystal growth process. When the dissolution of iron from the steel sheet during the phosphating treatment is insufficient, the hopeite epitaxial growth plane (020) conforms to the phosphophyllite epitaxial growth plane (100), and the mixed crystals with a high Zn/P ratio grow along the steel surface. When the dissolution of iron from the steel sheet is sufficient, the iron ion concentration in the solution increases, the intrinsically free precipitation of phosphophyllite without the restraint of epitaxy becomes predominant, and phosphate crystals with a lower Zn/P ratio grow.
The dissolution of iron from the steel sheet is accelerated by the oxides of manganese and silicon in a surface layer of up to 0.1 μm deep that is dissolved during the phosphating treatment.
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鈴木 信和, 坂東 誠治, 杉沢 精一
1991 年 77 巻 7 号 p.
1058-1065
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The phosphotability of Zn-Ni alloy electroplated steel sheets was investigated, and the influence of phosphate film appearance was discussed.
1) When the alkaline degreasing was weak in phosphate treatment, it happened that the phosphate film of Zn-Ni alloy electroplated sheets had "irregular flow pattern" appearance. In this case, electropainting film had same "irregular flow pattern" appearance.
2) The surface of Zn-Ni alloy which had less than 13 wt% Ni content was easily covered with zinc oxide, and then zinc oxidation controlled the phosphate reaction and caused "irregular flow pattern" phosphate appearance.
3) In order to prevent this "flow pattern" phosphate appearance, immersion post treatment in electroplating solution had good effect.
4) As compared with "irregular flow pattern" appearance phosphate film, uniform appearance phosphate film by immersion post treatment had good performance of wet adhesion as well as good electropaintability.
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三代沢 良明
1991 年 77 巻 7 号 p.
1066-1074
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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森田 操
1991 年 77 巻 7 号 p.
1075-1086
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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窪田 隆広, 山下 正明
1991 年 77 巻 7 号 p.
1087-1094
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Cationic electrodeposition primers have been widely adopted by automobile companies due to their advantages with regared to application and corrosion resistance. However, under certain conditions, cationic electrodeposition primers can give craters over precoated steel sheets. Therefore, it is important to establish the exact mechanism of cratering from the viewpoint of cratering control.
In this study, resistance-time profile which were calculated by means of measured current and voltage at the initial stage of electrodeposition were investigated using digitized measurements to record data over millisecond time scales. Uncured as-deposited paint film in the course of electrodeposition was observed by optical microscope, and defects remained in the deposited film at the end of electrodeposition was also observed during curing process by optical microscope. The results indicate that electrodeposited paint film is ruptured by violent hydrogen gas generated locally during electrocoating, and the defects remaind in the deposited film at the end of electrodeposition cause cratering after curing paint film.
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森 浩治, 輿石 謙二, 増原 憲一
1991 年 77 巻 7 号 p.
1095-1102
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Surface modification of poly (vinyl chloride) (PVC) coated steel sheet by electron beam induced graftpolymerization with various monomers was investigated. As solubility parameters δ of monomers increased, mutual solubility of monomers and plasticized PVC decreased. As a result, apparent graft decreased with increasing δ of monomers. Degree of stain for grafted PVC coated steel sheet decreased with increasing δ of monomers. It is assumed that graft chains, which consisted of monomers with larger δ, prevented plasticizer from migrating in the interior side of PVC film. As grafting temperature increased, thickness of graft layer and average graft concentration increased, and degree of stain decreased. On the other hand, formability of grafted PVC coated steel sheet decreased with increasing grafting temperature. Layer grafted with methacrylic acid was rigid and made formability of PVC coated steel sheet decreased. In case of grafting with 2-hydroxyethyl methacrylate, graft layer was more flexible and hardly spoiled excellent formability of original PVC coated steel sheet.
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酒井 健二, 池永 良樹
1991 年 77 巻 7 号 p.
1103-1108
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
クリヤー塗膜でS. W. O. M.ばくろの物性値(ヤング率・抗張力・伸び率),
Tg・弾性率,可塑剤残存率,塩ビ樹脂の分子量挙動におよぼす影響を確認た結果,
(1)物性値に関して,特に著しい変化を示したのは膜厚60μmの試料であった.
(2)
Tgおよび弾性率は,いずれの膜厚の試料もばくろ経時とともに上昇した.
(3)可塑剤残存率は,膜厚による差は大きくなく,いずれの試料も500hで二次可塑剤はすべて揮散していた.
(4)塩ビ樹脂の分子量挙動に関しては,膜厚60μmの試料は120μm,200μmの試料と比較すると分子量分布はブロードになっており500hで著しい変化を示した.また,カルボニル基の生成も膜厚60μmの方が激しかった.
また,ソルトスプレーテストの結果,膜厚60μmの試料は,カット部において120μm,200μmの膜厚の試料よりも劣っていた.顔料入り塗膜の外観変化をS. W. O. M.ばくろ3700h行ったが,3700hでのカルボニル基の生成および可塑剤残存率を調べた結果,クリヤー塗膜よりもカルボニル基の生成は少なく,また可塑剤残存率も高い値を示した.
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岸川 浩史, 大北 雅一
1991 年 77 巻 7 号 p.
1109-1115
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
30 years have passed since steel construction materials were used for base of the marine structures. But their corrosion rate was over the estimation, so development of effective anticorrosive system have been expected.
We examined the performance of 3 kinds of heavy duty coatings, urethane elastmer coating, tar urethane coating and powderd polyethylene coating which is able to be coated in the mill.
Urethane elastmer coating is the best of 3 coatings. It had superior performance balance and especially excellent corrosion resistance because of the primer which could keep adhesion strength in wet condition even if without chromate treatment.
Urethane elastmer coating wasn't damaged for driving test of coated steel sheet pile.
Now, urethane elastmer coated steel construction materials have been widely used for base of marine structures.
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杉本 克久
1991 年 77 巻 7 号 p.
1116-1121
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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林 公隆, 伊藤 陽一, 加藤 忠一, 三吉 康彦
1991 年 77 巻 7 号 p.
1122-1129
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
電気化学的手法を用いてめっき自体の腐食特性を詳細に調査した.これを基に乾湿繰返し環境(塩水散布大気暴露試験)下の塗膜下腐食最先端におけるZr-Fe合金めっきの腐食挙動を検討し,以下の知見が得られた.
(1)めっきのCl
-侵食耐久性がめっき自体の耐食性によることを明確化できた.
(2)めっき自体の腐食特性を把握する方法として電気化学的新手法であるカップル初期電流の測定手法を確立できた.
(3)めっきの塗膜下腐食は,酸素ガス拡散支配型ではなく電荷移動支配型の腐食機構で進行するものと考えられる.
(4)めっきの腐食は二つのミクロ回路の寄与,すなわちめっき上での腐食回路及びめっきと地鉄間の腐食回路の形成により進行する.
(5)大気暴露試験のような乾湿繰返し環境下では,めっきと地鉄間の回路を形成させる有効地鉄長は非常に小さいものと考えられる.
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岡 襄二, 高杉 政志
1991 年 77 巻 7 号 p.
1130-1137
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The effects of pretreatments and paint coatings on the edge creep performance of prepainted Galvalume were studied by means of salt spray test and outdoor exposure test. Edge creep progress behavior in salt spray test was different from that in outdoor exposure test. According to the results of outdoor exposure test for up to 10 years, the edge creep of prepainted Galvalume is more appreciable than that of the prepainted galvanized steel sheet in the early stages of exposure. However, the edge creep rate of prepainted Galvalume decreases with the lapse of time while that of prepainted galvanized steel sheet is kept almost constant. As the results, edge creep width becomes larger in galvanized steel sheet than in Galvalume in 7 to 9 years of exposure. Meanwhile in salt spray test, edge creep width of prepainted galvanized steel sheet does not exceed that of prepainted Galvalume up to 1000 h of exposure. Effects of pretreatments and coatings were not clearly noticed except that special primer for Galvalume decreased edge creep width of prepainted Galvalume in salt spray test.
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伊藤 陽一, 林 公隆, 三吉 康彦
1991 年 77 巻 7 号 p.
1138-1145
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The influence of the drying time ratio on the underfilm corrosion growth of zinc coated steel sheets at the leading edge of corrosion was investigated using salt spray/drying cyclic corrosion test.
The temperature and relative humidity were fixed at 35°C and 60%.
The dependence of the growth of underfilm corrosion on the zinc coating weight changes with drying time ratio. At high drying time ratio (93.8%) the underfilm corrosion rate decreases with an increase of zinc coating weight.
At the leading edge of underfilm corrosion of galvanized steel, anodic dissolution of zinc coating layer occurs from its upper side. This area increases with a decrease of drying time ratio. For salt spray test, the largest zinc dissolution zone was observed.
From these results, an underfilm corrosion mechanism of galvanized steel is thought to be as follows;
There are two kinds of corrosion electric cell. At the leading edge of corrosion, there is an anode followed by a cathode. There is an electric corrosion cell between the scribe and the zinc coating surface under the paint by the scribe. The proportion of these cells changes with drying time ratio, which change the underfilm corrosion ratio and morphological feature of galvanized steel sheets.
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水流 徹, 宇佐見 明
1991 年 77 巻 7 号 p.
1146-1153
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Photo acoustic images of coated steels degraded under cyclic corrosion tests were obtained by scanning a chopped and focused Laser beam and detecting the heat wave, which was produced by the beam, at the opposite side of the incidence. Amplitude of the signals was decreased and phase shift (time lag) of the wave measured with the incident beam was increased at the points where the delamination or under film corrosion occurred. The width of the delamination or the under film corrosion from the scribes of the coating was quantitatively evaluated, and it increased with the duration of the tests. The size and the area ratio of blisters formed around the scribes were also determined by this method. The spatial resolution of the images was achieved to 20 μm and discussed related to the measurement conditions, such as chopping frequency.
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坂内 恒雄, 国見 均
1991 年 77 巻 7 号 p.
1154-1161
発行日: 1991/07/01
公開日: 2010/01/18
ジャーナル
フリー
(1)自動車車体の腐食は内面と外面とで腐食環境もメカニズムも大きく異なるため寿命評価用にはおのおので最も適した促進試験法を適用しなければならない.
(2)内面腐食は基本的に塩分供給,乾燥,湿潤過程が組み込まれた試験法にて評価可能であり,内面腐食寿命を評価するにはむしろ実車の加工条件や形状をパラメーターにすべきである.
(3)外面腐食は大気腐食環境に大きく依存するため,外面腐食寿命を評価するには腐食の激しい特定の地域を基準にしたパネル温度,湿潤率,乾燥/湿潤繰返し数,塩の供給量等の環境因子を最重要パラメーターにすべきである.
(4)内面用および外面用台上腐食促進試験法により各種表面処理鋼板を評価した結果,車体用表面処理鋼板として有機被覆Zn-Ni合金めっき鋼板が優れていることが明らかになった.
今後さらに防錆長寿命化が進むとともに適材適所を基本としたきめ細かい防錆対策が求められ,地域別,車両部位別の最適促進試験法の確立がさらに必要になると考えられる.
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池田 貢基, 佐藤 廣士
1991 年 77 巻 7 号 p.
1162-1168
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The corrosion cracking phenomena of electro-deposited Zn-Ni alloy layers were investigated in relation to the coating structures. Zn-Ni alloy layers with nickel content over 10%, corresponding to γ single phase are subject to the corrosion cracking at potential more noble than their corrosion potential in an aqueous solution. The corrosion cracking of these layers can be prevented by thermal treatment at temperatures above 450°C. The corrosion cracking seems to occur by internal tensile stress generated by preferential dissolution of a small amount of zinc in Zn-Ni alloy layers.
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米野 實
1991 年 77 巻 7 号 p.
1169-1176
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
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塩田 明俊, 三木 賢二, 堺 裕彦, 野村 伸吾
1991 年 77 巻 7 号 p.
1177-1183
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Paint loss at the sheared and punched edge of pre-painted galvannealed steel sheet, so called enamel-hair, deteriorates corrosion resistance at the edge and mars appearance of paint film.
Effect of paint film and punching condition on the paint loss was investigated and this behavior was discussed by applying strain-induced grain growth. The results are summarized as follows;
(1) Polyester powder paint produced more paint loss than acryl solvent paint.
(2) Paint loss increased with an increase in punching clearance, an increase in punching speed and a decrease in punching temperature.
(3) Putting protect film on paint film increased paint loss in case of polyester powder paint and decreased paint loss in case of acryl paint.
(4) Microstructure of deformed base steel at the punched edge was studied by the strain-induced grain growth method. Behavior of paint loss can be explained by strain distribution at the edge and properties of paint film.
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安田 顯, 磯部 誠, 飛山 洋一, 大和 康二
1991 年 77 巻 7 号 p.
1184-1191
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
Both anti-powdering property and press-formability are the most important performances for the galvannealed steel sheet to be processed into automobile body panels successfully. The press-formability is to be strongly influenced by friction between the coating surface and the press-forming die. Because these properties depend on the coating compositions, it is meaningful to discuss the mutual relationship between these performances either in production of the material or in press-forming. The increase in Fe content of the coating deteriorated the anti-powdering property and decreased the friction resistance. The formation of
Γ phase at the interface of the coating and the substrate metal fatally affected the antipowdering property and the existence of ζ phase on the coating surface increased the friction resistance. In a view point of the Fe content, therefore, the friction property is contrary to the anti-powdering property. When the galvannealed steel sheet was electroplated with Fe-P alloy, the friction property was remakably improved. The friction property did not influence the delamination of the coating by bending but the amount of the coating peeling off at the shrinking flange in the cylindrical cup forming increased with the decrease of the friction resistance. It is supposed that the decrease in friction resistance increases the compression of material at the shrinking flange and that the compression enhances the delamination of the coating.
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藤本 慎司, 柴田 俊夫, 和田 浩司
1991 年 77 巻 7 号 p.
1192-1197
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
A thick film with interference color could be obtained on the surface of SUS3O4 stainless steel with the square wave potential pulse method in 5 kmol·m
-3 H
2SO
4 solution of 323 K with no addition of chromium ions. The higher potential,
EH, and the lower potential,
EL, of the square wave potential pulse were controlled in the range between the active peak potential and the transpassive potential of chromium. A thick colored film was obtained at the condition that
EL is kept in the transient region from the active peak to the passive range of chromium and
EH in the passive range of iron and chromium. The deposited hydroxide film including Fe
2+ and Cr
3+ formed at
EL losses protons and grows under the high field provided by
EH. The colored film thus formed has many diffusion paths, which permit the further growth of the film without any decrease in the growth rate. Therefore, the thickness of the film, i. e. the color, could be easily controlled by the polarization time and/or potential.
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北山 司郎, 志田 善明, 村山 順一郎
1991 年 77 巻 7 号 p.
1198-1205
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
The influence of surface condition on the anodization coloring behavior of titanium has been studied. It was found that uniform coloring was observed on polished surfaces while multiple coloring was observed on pickled surfaces. From the relationship obtained between crystal orientation of base metal and anodized film thickness, it was concluded that the film growth was faster on prism surfaces and was slower on basal surfaces. It was also confirmed by in-depth analysis of anodized surface on Ti alloy that the film was of inward growth type.
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加藤 誠, 園田 勉
1991 年 77 巻 7 号 p.
1206-1212
発行日: 1991/07/01
公開日: 2009/06/19
ジャーナル
フリー
In order to improve the biocompatibility of function-shared titanium-base alloy, coatings of pure titanium on the TiNi shape memory alloy and Ti-6A1-4V alloy were investigated. DC source was superior to RF source in characteristics of sputtered film and the rate of deposition. After cleaning method was examined, the sputtering conditions dependence of the thickness of sputtered film was investigated on DC sputter deposition. The sputtered titanium accumulated on substrate proportionally to electric power and showed orientation highly depended on the heating temperature of substrate. Complete denture bases of Ti-6A1-4V deformed by superplastic forming were well coated with pure titanium by DC sputtering in Ar gas atmosphere.
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