巻号一覧
45 巻, 11 号
選択された号の論文の8件中1～8を表示しています
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永井 欣一1976 年 45 巻 11 号 p. 926-937
発行日: 1976/11/05
公開日: 2011/08/05
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岩本 信也1976 年 45 巻 11 号 p. 938-945
発行日: 1976/11/05
公開日: 2011/08/05
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胡桃沢 竹重1976 年 45 巻 11 号 p. 945-951
発行日: 1976/11/05
公開日: 2011/08/05
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佐藤 邦彦, 松井 繁朋, 西村 岩夫, 飯山 英明, 千葉 尚道, 長谷部 茂雄, 別所 清1976 年 45 巻 11 号 p. 952-960
発行日: 1976/11/05
公開日: 2011/08/05
ジャーナル フリーWeld cracking is one of the most important problems in constructing steel structures. It has been investigated to estimate the occurrence of weld cracking by use of the factor such as the intensity of tensile restraint. However, weld cracking is sometimes caused by the angular distortion particularly in multipass weld.
The intensity of bending restraint is proposed as the parameter which evaluates quantitavely the restraint of the angular distortion. In this paper, the effect of the intensity of bending restraint on weld cracking in multipass weld is investigated by use of a newly developed small size test called "Bending Restraint Weld Cracking test (BRC-test)". The occurrence of weld cracking in actual structures is similar to that in the BRC-test. Therefore, the occurrence of weld cracking in actual structures can be predicted by use of the intensity of bending restraint of the structures based on the results of the BRC-test.抄録全体を表示PDF形式でダウンロード (1802K) -
稲垣 道夫, 和田 次康, 保田 正文, 関口 晁1976 年 45 巻 11 号 p. 960-966
発行日: 1976/11/05
公開日: 2011/08/05
ジャーナル フリーThe CO2-O2 arc welding process is done in strong oxidation atmosphere with a wire containing Si and Mn which are deoxidizing elements. Dr. H. Sekiguchi pointed out that mechanical properties of welded metal were significantly influenced by the content of these elements and there was a proper range of their contents. Therefore, an investigation was made on the oxidation behaviour of Si and Mn. Six kinds of wire containing different amounts of Si and Mn were used. Their compositions correspond to the ranges in which SiO2 of solid state (Field I) and liquid solution of FeO-MnO-SiO2 unsaturated with SiO2 (Field II), respectively, form as a deoxidation product from molten steel just above the solidification point. The multi-pass welding was made with all of the wires under various conditions of arc voltage and oxygen content of shielding gas. Samples taken from upper layer of deposited metal were analyzed. Furthermore, slag covering the weld bead of upper layer was also analyzed.
Thus, the following results were obtained.
(1) It was recognized that the oxidation consumption curve of Si and Mn shows the same tendency regardless of wire composition in Field I or II.
(2) Si and Mn are oxidized with a fixed ratio when welding is performed with different oxygen content of shielding gas or arc voltage. The ratio is dependent on the wire composition. That is, the relation between Si and Mn content of wire and those of deposited metal can be shown as follows.
log (w/o Si) =A log (w/o Mn) +B
constant A is about 1.7 and constant B is determined from the wire composition.
(3) Accordingly, the composition of wire to be used is to correspond with constant B determined from the aimed composition of deposited metal.
(4) Thermodynamic considerations show that, although equilibrium between Si or Mn in weld metals and SiO2 or MnO in slags is not completely achieved, their deviation from equilibrium is relatively small, and the deviation in oxidation of Si and that in oxidation of Mn are of similar level.抄録全体を表示PDF形式でダウンロード (473K) -
水圧の溶接結果および溶接現象への影響蓮井 淳, 菅 泰雄, 当麻 英夫1976 年 45 巻 11 号 p. 967-974
発行日: 1976/11/05
公開日: 2011/08/05
ジャーナル フリーThe feasibility of gravity arc welding (DCSP) and welding phenomena under water pressures from 0.03 to 6 Kg/cm2 (guage pressure) are investigated. The 4 mm diameter coated electrodes of five types and the SM41 steel base metals of 6 and 9 mm thickness are used.
Main experimental results are summerized as follows:
(1) Welding arc can be generated easily and kept in stable under water pressures from 0.03 to 6 Kg/cm2, if only proper welding conditions are selected. Especially the high titanium oxide type electrode waterproofed by laquar has relatively good weldability.
(2) The porosity in weld metal increase with an increasing water pressure.
(3) The butt welded joints obtained under 0.03, 3 and 6 Kg/cm2 pressures have sufficient tensile strength in as-welded condition. However, the tensile strength of weld metal decreases with increase of water pressure.
(4) Carbon content of weld metal is raised to some extent with increase of water pressure and manganese and silicon contents are reduced. And hardness distribution in weld metal lowers as water pressure increases.
(5) The thermal pinch effect on arc column is enhanced by increase of water pressure and constriction of arc column becomes stronger.
(6) The anode spot on base metal and cathode spot at tip of core wire fluctuate more violently as water pressure increases.
(7) Water pressure decreases melting rate of electrode.抄録全体を表示PDF形式でダウンロード (8044K) -
益本 功, 赤石 徹, 照沼 俊克, 村松 修一1976 年 45 巻 11 号 p. 975-980
発行日: 1976/11/05
公開日: 2011/08/05
ジャーナル フリーIt was previously reported that fatigue strength of butt welded joint of SM41 steel, 60 kg/mm2 and 80kg/mm2 high strength steels could be improved by hot dip galvanizing and quenching, and the reasonfor this improvement may, be explained by compressive residual stress and aging effect by quenching from a temperature lower than A1 temperature. This aging effect of steel plates depends on chemical composition, heating temperature, time and cooling rate. In the present study the effect of heating-quenchingmethods, temperature and artificial aging treatment on the improvement of butt welded joint are examined.
The results by this experiment are as follows.
1.Fatigue strength of butt welded joints of three kinds of steel is improved by low temperature quenching.
2.In the case of the same heating temperature, furnace heating is more effective than hot dip galvanizing, because heating time in furnace is longer than in zinc bath.
3.In the case of mild steel and 50 kg/mm2 high strength steel, the higher the temperature beneath A, temperature is, the more increase in fatigue strength of welded joints is obtained.
4.In the case of 60kg/mm2 high strength steel, it was observed that there was suitable hegting temperature depending on the precipitation behaviour.
5.The most important factor in fatigue strength improvement by these heat treatments was consideredaging effect. And spherization ofcementite also seemed to be one ofthe factors in the case of 700°C furnaceheating-quenching.抄録全体を表示PDF形式でダウンロード (2166K) -
益本 功, 赤石 徹, 米川 俊之, 村松 修一, 福智 久1976 年 45 巻 11 号 p. 980-985
発行日: 1976/11/05
公開日: 2011/08/05
ジャーナル フリーIt was already reported that quenchings from a temperature under A1 point improved the fatigue strength of steel welded joints, and the reasons of this fatigue strength improvement was attributed to quench aging effect and compressive residual stress in surface layer.
On the other hand, aging of steel has a liklihood to make a embrittlement of steel. This experiment was carried out to clarify the effect of this fatigue strength improving heat treatment (low temperature quenching) on the toughness of welded joint.
Each welded joint of rimmed steel, 50 kg/mm2 and 60 kg/mm2 steel was heated by hot dip galvanizing, at 500°C and 700°C in furnace, followed by quenching into about 20°C water. Toughness of toe of welded joint was investigated by i) Standard V notch Charpy Impact Test ii) COD Test and iii) ESSO Test.
The following results were obtained,
1) The results of Charpy impact test and COD test showed that toughness of SS41, SM50 and HT60 steel welded joints did not decreased remarkably compared with as welded joint by a low temperature quenching.
2) The ESSO test result showed that crack arrest temperature of SM50 steel welded joint slightly increased by low temperature quenching, but crack arrest temperature of SS41 and HT60 steel welded joints were nearly same compared with as welded joints.抄録全体を表示PDF形式でダウンロード (380K)
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