巻号一覧
44 巻, 3 号
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Egon Schlebeck, Manfred Gerlack, Jörn Burmeister1975 年 44 巻 3 号 p. 188-192
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーPDF形式でダウンロード (3075K) -
伊藤 慶典, 香山 晃1975 年 44 巻 3 号 p. 193-201
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーEffect of interstitial impurities, especially for nitrogen, on impact properties of submerged arc welded metal was investigated using a new technique through which only nitrogen content was varied.
The results are summarized as follows.
1. Snoek's internal friction peak intensity of weld metal shows lower value than as normalized mild steel which comes mainly from existence of texture and short mean ferrite path. Solute nitrogen content (A wt%) is thought to be calculated as
A(wt%)=7.0×Q-1_max
where Q-1_max is Snocek's peak height.
2. Internal friction curves of weld metal are separted into four single relaxation peaks, C, Nl, N3 and N4, which are thought to be carbon Snoek's peak, nitrogen Snoek's peak and N-Mn interaction peaks respectively, and deform shaped relaxationpeak, X-peak.
3. Ductility of weld metal decreases gradually as total nitrogen content increases but at low nitrogen content level this ductility dependence on nitrogen shows reverse tendency.
4. Ducitility of weld metal decreases as solute nitrogen content increases and for HT-60 specimen which varies almost proportionally.
5. The main role of nitrogen on impact properties of weld metal is thought to be that solute nitrogen and secondary solute nitrogen which interact with other impurity lattice atoms rasise frictional force of dislocation to decrease ductility of weld metal.抄録全体を表示PDF形式でダウンロード (5761K) -
益本 功, 篠田 剛, 田島 直之1975 年 44 巻 3 号 p. 202-210
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーAlthough there are many data on the mechanical properties and toughness of weld metals of various kinds of coated electrode, only a few of reports will be found on the effect of types of coated electrode on the fatigue strength of welded joint, e.g. it is well known that the weld metal by low-hydrogen lime type electrode has better toughness than those by other type electrodes, but a low-hydrogen lime type electrode gives more rough and irregular bead form in comparison with other type electrodes. Therefore, it is not always clear, which type of electrode will give more beneficial welded joint in relation to its fatigue strength.
This point was experimentally studied by this report. The obtained results are as follows:
1) In the case of the same electrode, the fatigue strength of the vertical welded joint with reinforcement is 2-6 kg/mm2 lower than that of the flat welded joint.
2) The welded joint with reinforcement by low-hydrogen type electrode gives the higher fatigue strength of welded joint in comparison with other type electrodes.
3) Titania type electrode gives the lowest fatigue strength of welded joint of all.抄録全体を表示PDF形式でダウンロード (3742K) -
佐藤 邦彦, 豊田 政男, 小田 勇1975 年 44 巻 3 号 p. 211-219
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーThe characteristics of brittle fracture and fatigue failure in the body which has several cracks and defects being close to each other, are different from those in the body having single crack due to the interaction.
For the plate containing parallel cracks of equal length, it is reported recently that not only the brittle fracture stress but also the critical COD are larger than those for the plate containing single crack and increase with decrease of distance of parallel cracks. Accordingly, the COD concept is not simply applicable to that case.
In this report, deformation behaviors such as stress, strain, plastic zone size ahead of crack tip and COD in the plate containing two parallel equal length cracks under uniaxial tension are investigated by the elastic-plastic analysis based on the finite element method and the experiment.
Main results obtained are as follows: COD of parallel cracks under same load decrease with decrease of distance of cracks. When COD is constant, magnitudes and distributions of stress ay and strain sy in tensile direction around crack tip are much the same regardless of distance of cracks and yet distributions of σx differ with distance of cracks. Moreover, it is shown that the parameter with respect to the brittle fracture initiation may possibly exist which is dependent on triaxiality of stress around crack tip.抄録全体を表示PDF形式でダウンロード (2134K) -
溶接用SH-CCT図におよぼすMoの影響春日井 孝昌, 稲垣 道夫1975 年 44 巻 3 号 p. 220-228
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーThe effect of Mo on transformation behaviour in synthetic weld heat-affected zone of steel was investigated using simplified steels made of pure metals and graphite. Mo element displaced the SH-CCT diagram for ferrite and pearlite transformation regions to a longer time, and extended Zwischenstufengefüge (Zw) transformation region to a longer time. Each critical cooling time Cf', Cp' and Ce' increased with Mo content.
Morphologies of ferrite, pearlite and Zw were strongly influenced by Mo. In the region of longer cooling time (cooling time from A3 to 500°C; above 60 sec), the growth of massive ferrite and ferrite sawteeth were controlled by the addition of Mo, and fine colony pearlite formed between both ferrite sideplates or both rodlike ferrites precipitated more easily than lamellar or degenerate pearlite. In the case of middle and shorter cooling time (cooling time; under 60 see), ferrite sideplate and rodlike ferrite or needlelike ferrite were more liable to develop than massive ferrite and ferrite sawteeth, and fine colony pearlite formed more easily than other pearlite. Zw accompanied with fine carbide precipitated easily in this region of cooling time.
Mo element rasied the hardenability curves in synthetic weld heat-affected zone of steels. It seemed that the hardness is influenced considerably by the morphological change of, ferrite. The effect of Mo on the hardness of martensite was a little.抄録全体を表示PDF形式でダウンロード (11544K) -
井川 博, 新 成夫, 中尾 嘉邦, 西本 和俊1975 年 44 巻 3 号 p. 229-235
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーIn this study, diffusion phenomenon of carbon and dissolution phenomenon of graphite in spheroidal graphite cast steel were researched in the case of both time and temperature varying simultaneously such as weld thermal cycles.
Experimental results obtained in this study are as follows;
(1) Diffusion phenomenon of carbon from graphite particle to matrix in the austenitic temperature range during weld thermal cycles can be explained phenomenologically by equation (4) in the initial stage of diffusion phenomenon.
(2) The critical dissolution curve of graphite in the austenitic temperature range during weld thermal cycles obtained by equation (8) shifts slightly to the left from the critical dissolution curve determined experimentally.抄録全体を表示PDF形式でダウンロード (6136K) -
鋼材の腐食疲れにおよぼす合金元素の影響益本 功, 赤石 徹1975 年 44 巻 3 号 p. 236-240
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーThe final purpose of this study is to clarify corrosion fatigue behaviour of steel plates and welded joints.
In this report, the effect of alloyed elements on corrosion fatigue of steel plate was described.
Results obtained are as follows:
1) In air, fatigue strength of low carbon steel alloyed by phosphor was increased than that of low carbon Si-Mn steel, but no effect of titanium, copper and chromium alloying was observed on the fatigue strength.
2) The effect of alloyed elements on the increment of corrosion fatigue strength in 3% NaCl aq. solution was observed not at all. Conversely, corrosion fatigue strength of titanium-alloyed low carbon steel was very low value.
3) Fatigues trength in air increased with the increment of the tensile strength of steel plates, but corrosion fatigue strength was not varied in spite of increment of the tensile strength.
4) Corrosion fatigue test in 3% NaCl aq. solution showed no endurance limit.抄録全体を表示PDF形式でダウンロード (1427K) -
渡辺 潔, 志田 朝彦, 森成 良佐, 皆川 貞利, 佐々木 秀昭, 和井 伸一1975 年 44 巻 3 号 p. 241-249
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーParallel gap resistance welding of Ag plated 0.18 mm diameter oxygen free copper wires to three types of patterns (solder plated, Au plated, Au+Ni plated) of printed circuit boards (P/B) was investigated. Formation of weld fillets, metallurgical microstructures and mechanical properties of the welds were examined and some analysis of weld mechanism was made.
The results are summarized as follows.
A. Welding to the solder plated P/B,
1) Weld strength is held by Cu-Ag-Sn alloying phase in the pressure weld area of the wire and the pattern under the electrode indentation.
And the solder fillet does not contribute to weld strength.
2) Linear relation is recognized between weld strength and the maximum pressure weld width.
B. Welding to the Au and Au+Ni plated P/B,
3) When the weld fillet is small, weld strength is held by the pressure weld area as is in the case of the solder plated P/B. When large fillets are formed, weld strength is held by them.
4) Au plating has the role as the brazing agent.
5) Ni plating is effective for prevention or decrease of thermal damages to the pattern and the substrate.抄録全体を表示PDF形式でダウンロード (9459K) -
上田 幸雄, 福田 敬二, 中長 啓治1975 年 44 巻 3 号 p. 250-257
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリーDealing with cold cracking of welded joints, it is rather convenient to devide the type of joint into two; butt and fillet welded. For butt joint, many good research works have been done and detail in-formation of the joint during welding has been provided.
On the other hand, concerning cold cracks of fillet weld, many experimental researchs have been performed. With slight changes in the restraint for thermal deformation, various types of cracking have been observed, for example, at the toe and root, and under bead on the web side, and at the toe, heel and root on the flange side, etc., since local stress strain history may differ to a great extent.
In this paper, a series of theoretical analysis of elastic-plastic behavior of fillet weld of the first bead was performed under various restraining conditions for steel of 50 kg/mm2 by the finite element method developed by one of the authors. Based on the results of the theoretical analysis, the following information was obtained.
(1) When the restraint for uniform contraction of web is low, possible weld cracks many occur at the toe, root, and heel on the flange side, on the other hand, when this restraint becomes higher, the crack initiation is considered to move on the web side, such as at the root, toe, of the weld of the web. When the restraint is extremely strong, crack initiates at the root on the web side and propagates to the toe on the flange side.
(2) When the restraint for rotation is low, the type of cracking is just similar to the previous case where the restraint for uniform contraction is low. When this restraint becomes severer and constrains free contraction along the flange, crack may be observed at the toe on the flange.
(3) When fillet weld is laid on both sides of T-connection, crack is liable to occur in the first fillet weld, since the restraint stresses of the second weld are superimposed on the residual stresses produced by the first one. And cracks may be located at the root on the web and the toe on the flange.抄録全体を表示PDF形式でダウンロード (444K) -
風によるアークの最大長さの変化の定量的把握と実験式の導入棟 徹夫1975 年 44 巻 3 号 p. 258-264
発行日: 1975/03/05
公開日: 2011/08/05
ジャーナル フリー本研究の第1報および第2報を通じて明らかにした溶接アークの最大長さと風速の関係を定量化するため,若干の関連因子をパラメータとする実験式を提唱し,その誘導をはかった.また,溶接アークに対する風の阻害作用の極限として,アークの発生を不能にする限界風速を定義し,実験的にその特性を明らかにし,次のような結果を得た.
(1)被覆溶接におけるアークの最大長さと風速の関係は,風速がほぼ1m/sを越えると双曲線的に変化することが判明し,それにもとづき実験式が誘導された.実験式の係数は電流,被覆剤厚さによって異なる.風速が1m/s以下になると,実験曲線は実験式の示す双曲線からはつれる.
D4303の場合,
120Amp.ではL=23ν-0.508
200Amp.ではL=31/ν-0.436
裸心線の場合,
120Amp.ではL=10.5ν-0.330
200Amp.ではL=17ν-0.333を得た.
(2)アークの最大長さと被覆剤厚さの関係は,被覆剤厚さtと心線半径rとの比t/rを数変とする場合,放物線的に変化することを確かめ,実験式が誘導された.この場合t=0(心線のみの場合)に近づくにしたがい,実験曲線は実験式の示す放物線からはつれる.
ν=0m/sの場合,
120Amp.ではL=22.71(t/r)0.174
200Amp.ではL=25.70(t/r)0.170
ν=8m/sの場合,
120Amp.ではL=6.31(t/r)0.226
200Amp.ではL=8.49(t/y)0.217を得た.
この場合,被覆剤厚さについての変数をどのように設定するかで関数関係が若干異なって誘導され,有効な実験式の導入が困難になることが判明した.
すなわち,t/γならびに研削後の被覆剤断面積と最初の被覆剤断面積の比を変数とすれば,実験式はともに放物線を示すが,研削後の被覆剤厚さtと最初の厚さtmaxとの比t/tmaxを変数とした場は,片対数目盛上で直線となり,実験式として複雑になり適用しにくい結果を得た.
(3)アークの最大長さの風による減少比[L(ν)/L(o)]と風速の関係は,ほぼ双曲線的関係を示す.裸心線は電流にかかわらず,実験風速の全領域(データ上からは2.5m/s以上)において双曲線に沿うが,被覆剤のある場合は,総体的に双曲線的変化を示すが,厳密さを加えれば,低電流域(120,160Amp.)では高速側または低速側において部分的に双曲線に沿う,若干の変動が見られた.
しかし,高電流域(200Amp.)では裸心線と同様,全風速域で双曲線的変化が得られ,有効な実験式の誘導が可能なことが判明した.
(4)アークの最大長さの減少比と被覆剤厚さの関係は電流をパラメータとした場合,放物線に近似した曲線を画くが,高電流域が曲線の上限を,低電流域が下限を形成した.上阪曲線は風速にかかわらず放物線形状を維持するが,下限曲線は風速が増大すると形状が崩れ,低風速域とは異なる形となる.この場合は有効な実験式の誘導には至らなかった.
(5)風によって溶接アークがかく乱される極限条件として,アークの発生が不能となる限界風速を定義し測定観察した結果,限界風速は通常の被覆溶接棒の使用状況でほぼ30m/sであることが判った.限界風速は電流の増大,被覆剤厚さの増加,電極一母板間距離の短縮によって高い値を示す,被覆剤厚さが減少する初期の段階では限界風速の低下はゆるやかで,曲線的であるが,ある厚さ以下になると直線的に急激に下降する.
電極一母板間距雛が一定の場合,限界風速は溶接棒保持角に依存し,Θ=π/4の方がΘ=π/2の場合より高い限界風速が得られた.これは著者の研究を通じて提起したπ/4保持角の風に対する有効性を立証したものといえる.抄録全体を表示PDF形式でダウンロード (1835K)
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