巻号一覧
41 巻, 6 号
選択された号の論文の9件中1～9を表示しています
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荒田 吉明, 井上 勝敬1972 年 41 巻 6 号 p. 613-648
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーPDF形式でダウンロード (17455K) -
小林 卓郎, 桑名 武, 小山 真弘1972 年 41 巻 6 号 p. 649-662
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーUsing six series of aluminum-alloy electrode wires, bead-on-plate specimens were made in Ar-N2 mixed gas atmospheres. The effects of titanium, zirconium, silicon, copper, zinc and magnesium in electrode wires on the surface appearance, depth of penetration, porosity and nitrogen content of weld metals were systematically studied.
The main results obtained are as follows:
(1) Al-Ti, Al-Zr, AI-Si and Al-Cu wires are prone to cause puckered welds at PN2=0.1-0.5 atm (PAr=0.9-0.5 atm).
(2) Zinc and magnesium are effective alloying elements to prevent puckering phenomena in Ar-N2 atmospheres.
(3) Use of Al-Zn and Al-Mg wires gives rise to good profiles of penetration even in nitrogen- rich Ar-N2 atmospheres.
(4) Use of Al-Ti, Al-Zr, Al-Si and Al-Cu wires increases the porosity of aluminum welds in Ar-N2 atmospheres.
(5) The nitrogen content of weld metals decreases with increasing Ti, Zr, Si, Cu, Zn and Mg contents in electrode wires.
(6) From the view point of welding process, Al-Zn or Al-Mg electrode wires are fit for the Ar-N2 gas metalarc welding of aluminum.抄録全体を表示PDF形式でダウンロード (7163K) -
立川 逸郎, 小田 明1972 年 41 巻 6 号 p. 663-674
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリー爆接18Cr-8Niステンレスクラッド鋼の加熱処理に伴う冶金的挙動を詳細に明らかにした.おもな結論はつぎのとおりである.
i)500°～900℃の加熱により,ステンレス鋼合材の全断面にわたってCr炭化物が折出するが,これは爆接時に合材が受けた塑性ひずみにより促進される.
ii)接合部では炭素の軟鋼からステンレス鋼への拡散移動が起こり,600°～700℃ではステンレス鋼境界に沿う約50μの深さにわたって,Cr7C3を主体とする異常に高い硬化層が生成する.加熱温度が900℃になると,炭化物はステンレス鋼内部に分散しかたさは低下する.同時にCr7C3のほかにCr23C6およびσ相が析出する.他方,Cr,およびNiが軟鋼側へ拡散し,ステンレス鋼境界には析出相のないステンレス鋼と軟鋼との中間組成をもつ合金層が生成する.1100℃ではこれらの析出物はオーステナイト素地中に再固溶する.
iii)爆接時に境界部に生じた溶融層は,加熱によりしだいに軟化し,かつCr炭化物を析出する.
iv)アークによる短時間加熱では,接合境界層の軟鋼およびステンレス鋼において脱炭と炭化物析出がそれぞれわずかに生起する。また,ステンレス鋼の熱影響部にはγ+α(δ)の共存域を生成する.抄録全体を表示PDF形式でダウンロード (17691K) -
明石 重雄, 夏目 光尋1972 年 41 巻 6 号 p. 675-686
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーThe objective of this study was to investigate the root-cracking in welded joints with restraint and to find the suitable welding procedure corresponding with the intensity of restraint.
Large H-type specimen and variable restraint equipment were used to simulate four steps of restraaint, and five kinds of steels were submitted to testing.
The conclusions are as follows:
(1) Welded joint length of at least 150 mm appeared to be necessary for the crack testing from the study of stress distribution of H-type specimen.
(2) The ranges of restraint intensity free from root-cracking were found as shown in Fig. 13. It is noteworthy that the low alloy 50 kg/mm2 strength steels have a high crack susceptibility.
(3) Two or three passes welded under 10 minutes intervals are as much efficient as preheating to prevent root-cracking, whereas they have no effect to decrease the restraint stress.抄録全体を表示PDF形式でダウンロード (1884K) -
沢入 操, 田中 良平1972 年 41 巻 6 号 p. 687-694
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーAn experimental study was made on the weldability of 18Cr-10Mn stainless steels containing high concentration of nitrogen up to about 0.8%, prepared by a high-pressure melting process in nitrogen atmosphere. Main results obtained are as follows.
(1) In the arc welding of high nitrogen l8Cr-10Mn stainless steels, if ordinary welding conditions recommended for welding commercial austenitic stainless steels are adopted, we shall usually be able to get excellent and sound welded joints.
(2) In case of welding by using the electrode having the same composition, the tensile strength of welded joints increases in proportion to the nitrogen content of base metals. This strengtheing in the welded joints depends upon the extent of nitrogen diffusion, which occurs from the base metal to the welded metal.
(3) The decrease of impact strength in heat-affected zone scarcely occurs even in the steel containing about 0.8% nitrogen.
(4) While the base metal is melting, the nitrogen contained in the base metal diffuses and blows out of the metal a little. Consequently, in the base metal containing high concentration of nitrogen i.e. more than 0.65%, blowholes in the weld deposit increase and the concentration of nitrogen in the heat-affected zone decreases a little.
(5) But, the decrease of nitrogen content in the base metal occurs only in the limited portion near the weld bond, and the amount of the decrease is small. Therefore, in the steels containing nitrogen less than about 0.65%, the decrease of the nitrogen content scarcely influences the mechanical properties and the microstructures of the welded joints.抄録全体を表示PDF形式でダウンロード (3025K) -
80kg/mm2高張力鋼大入熱潜弧熔接ボンドの破壊特性佐藤 誠, 中杉 甫1972 年 41 巻 6 号 p. 695-699
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーA study was made on prevention of brittle fracture in a high heat input welded joint for 80kg/mm2 high tensile steel and a metallurgical investigation into the improvement of cleavage fracture strength of weld bond was carried out.
In this report the fracture characteristics of conventional HT80 steels' welded joints welded with 80 KJ/cm heat input are clarified. They fracture at weld bond in a brittle manner at 15-20°C.
And the clue to prevention of brittle fracture is discussed according to fracture analysis diagram.
It is stressed that the solution to this problem lies in the fact that the compound microstructure of low carbon bainite and low .carbon martensite has superior notch toughness and higher yeild stress.
Namely, the higher the notch toughness and the higher the yield stress are in weld bond, the tendency of weld bond brittle fracture becomes the lis less conspicuous.抄録全体を表示PDF形式でダウンロード (1551K) -
坪井 潤一郎, 坂本 昇, 美浦 一彦1972 年 41 巻 6 号 p. 700-708
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーIt is often observed that the shape of horizontal fillet weld bead is influenced by welding variables and flux.
From the viewpoint of the interfacial tension phenomena, this study was done to investigate the relation among the shape of horizontal fillet weld bead, welding variables and flux composition.
Firstly, a theoretical consideration on the formation of horizontal fillet weld bead was made on the assumption that the shape of weld bead would be determined by the balance of interfacial tensions between slag, molten metal and solid metal, gravity of liquid metal and so forth.
Secondly, the effect of interfacial tension between slag and metal on the bead shape was examined experimentally.
The interfacial tension was measured by a new method proposed in this paper.
That is, flux and wire were melted by TIG arc in a copper crucible cooled with water. The interfacial tension was calculated from the shape of a frozen steel drop.
The following results were obtained:
(1) The shapes of horizontal fillet weld bead are classified into three types in submerged arc welding.
(2) The main factor which determines the bead shape of submerged arc horizontal fillet weldindg is the interfacial tension between slag and metal.
(3) In order to get a good shaped horizontal fillet bead, it is necessary to use a flux which exhibits as large values as possible of interfacial tension and specific gravity.
But, according to theoretical consideration, more than 9.5 mm of leg length could not be attained for the horizontal fillet bead welded in one pass.
(4) It was confirmed that the interfacial tension between molten slag and molten metal was able to be measured by the shape of a frozen steel drop.
(5) With the above-mentioned method, the interfacial tension between weld slag and wled metal was measured.
The values of the interfacial tesion were 1250 dyne/cm for the maximum case and 750 dyne/cm for the minimum case, respectively.抄録全体を表示PDF形式でダウンロード (5363K) -
一般構造用材料に対する検討仙田 富男, 松田 福久, 高野 元太, 渡辺 潔, 小林 忠明, 松坂 矯1972 年 41 巻 6 号 p. 709-723
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーIn fusion welding of constructional ferrous and non-ferrous materials solidification cracking frequently occurs in the weld metal when a great deal of distortion and shrinkage takes place in the parent and weld metals due to a local rapid weld heat cycle. The occurrence of this solidification cracking, which is a kind of hot cracking, often gives rise to serious problems for some constructional materials from a view-point of weldability.
Meanwhile those constructional materials including commercially pure metals have a brittleness temperature range during solidification whose ductility is very low to cracking.
The properties in the solidification brittleness range such as temperature difference, minimum ductility and shape of ductility curve depend upon the kind and amount of impurities or alloying elements in the materials. Increasing the temperature interval and decreasing the minimum ductility are considered to increase the susceptibility of solidification cracking for the material in general.
Unfortunately, however, there are few reports, so far, concerning the properties in the solidification brittleness range during welding of the constructional materials in spite of their close relation to solidification cracking.
In this report authors have firstly investigated the nominal susceptibility of solidification cracking during TIG arc bead-on-plate welding for various constructional materials of carbon steels, low alloy high tensile strength steels, austenitic stainless steels, aluminum and aluminum alloys and brass, using the Trans-Varestraint Tester which was modified from the original Varestraint. Secondly, utilizing the relationship between the maximum crack length occurring in the center of weld metal with the Trans-Varestraint Test and the temperature distribution during welding which was actually measured, the properties of the solidification brittleness range have been investigated for the weld metals of the materials.
Lastly, authors have proposed new indices, the critical strain rate for temperature drop (CST), which reasonably evaluates the solidification crack susceptibility of material during welding and the critical strain rate to time (CSS), which is easy to measured and is substituted for (CST) under a limited condition.抄録全体を表示PDF形式でダウンロード (11790K) -
1972 年 41 巻 6 号 p. 734-741
発行日: 1972年
公開日: 2011/08/05
ジャーナル フリーPDF形式でダウンロード (3341K)
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