Pub Date : 1982-10-01DOI: 10.2207/QJJWS1943.50.392
K. Satoh, Kazuhiro Nohara
The present paper deals with the effect of welding conditions, plate length and tack weld pitch on changes of root gap during welding in butt weld joints. The calculations of changes of root gap during welding are carried out under various conditions of heat input, plate length and tack weld pitch, using the finite element method explained in the previous report. In this case it is assumed that the rigidity of tack weld is infinite. The main conclusions obtained in this report are summarized as follows:
{"title":"Changes of Root Gap during Welding in Case of Butt Weld Joints (3rd Report) : In Case of Butt Weld Joints with Tack Welds","authors":"K. Satoh, Kazuhiro Nohara","doi":"10.2207/QJJWS1943.50.392","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.392","url":null,"abstract":"The present paper deals with the effect of welding conditions, plate length and tack weld pitch on changes of root gap during welding in butt weld joints. The calculations of changes of root gap during welding are carried out under various conditions of heat input, plate length and tack weld pitch, using the finite element method explained in the previous report. In this case it is assumed that the rigidity of tack weld is infinite. The main conclusions obtained in this report are summarized as follows:","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117093829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-10-01DOI: 10.2207/QJJWS1943.50.379
Kiyoe, K. Hirabayashi, T. Taira, H. Ichinose
The development of three wires submerged arc welding techniques was carried out to produce line-pipes in the large-diameter and heavy-wall-thickness from 20 to 50 mm by UOE process. Some factors on a sound weld metal and a bead shape have been clarified as follows.(1) The good correlation between the penetration depth of the weld bead and the sum of 3√ I4/v⋅V2a at the leading and the middle wire could be obtained. The bead width had the good correlation with the heat input, and it was spread by an increase of the welding current and/or the arc voltage at the middle and the trail wire or by a decreasing of the welding speed.(2) The stable arc voltage and the good bead appearance can be obtained in the use of a large diameter welding wire because of lowering down the current density in it. The wire of 4.0 mm in diameter is too small to get a good weld bead, but the wire of 6.4 mm in diameter is so rigid that undercuts in the weld bead are sometimes caused by the unstable wire feeding. As a result the optimum wire may be 4.8 mm in diameter.(3) As lengthening a wire spacing, nitrogen and oxygen content in a weld metal are increased and they deteriorate the Charpy value, so that each wire spacing is desired to set within about 30 mm.(4) To get the high welding speed due to increasing a melting rate may be to weld at a high welding-current, but in this case, weld defects of the bead appearance such as undercuts are caused because of the hunting of the arc voltage happened by higher welding-current. Therefore sums of the welding current in three wires are desired to be about less than 3000 Amp. and the welding current at each wire is limited in the use of the fused flux.
{"title":"Development of Three Wires Submerged Arc Welding Technique for the Production of Large Diameter and Heavy Wall Thickness Line Pipes (Report 1) : Factors on Bead Shape and Sound Weld Metal","authors":"Kiyoe, K. Hirabayashi, T. Taira, H. Ichinose","doi":"10.2207/QJJWS1943.50.379","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.379","url":null,"abstract":"The development of three wires submerged arc welding techniques was carried out to produce line-pipes in the large-diameter and heavy-wall-thickness from 20 to 50 mm by UOE process. Some factors on a sound weld metal and a bead shape have been clarified as follows.(1) The good correlation between the penetration depth of the weld bead and the sum of 3√ I4/v⋅V2a at the leading and the middle wire could be obtained. The bead width had the good correlation with the heat input, and it was spread by an increase of the welding current and/or the arc voltage at the middle and the trail wire or by a decreasing of the welding speed.(2) The stable arc voltage and the good bead appearance can be obtained in the use of a large diameter welding wire because of lowering down the current density in it. The wire of 4.0 mm in diameter is too small to get a good weld bead, but the wire of 6.4 mm in diameter is so rigid that undercuts in the weld bead are sometimes caused by the unstable wire feeding. As a result the optimum wire may be 4.8 mm in diameter.(3) As lengthening a wire spacing, nitrogen and oxygen content in a weld metal are increased and they deteriorate the Charpy value, so that each wire spacing is desired to set within about 30 mm.(4) To get the high welding speed due to increasing a melting rate may be to weld at a high welding-current, but in this case, weld defects of the bead appearance such as undercuts are caused because of the hunting of the arc voltage happened by higher welding-current. Therefore sums of the welding current in three wires are desired to be about less than 3000 Amp. and the welding current at each wire is limited in the use of the fused flux.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128376532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-10-01DOI: 10.2207/QJJWS1943.50.508
Y. Nakao, K. Nishimoto, M. Terashima
Effect of REM addition on the toughness in the weld metal of high purity 30Cr-2Mo steel was investigated. Welding was carried out by TIG method using deliberately contaminated argon with various ratio of nitrogen or air as shielding gas in order to vary the toughness of weld metals. The toughness of weld metals was evaluatedd using sub-size Charpy V-notch specimens with thickness of 3 mm. The main results obtained in this study are as follows;1) The toughness of the weld metal is significantly improved by addition of REM. Effective content of REM ranges from about 50 ppm to 200 ppm when nitrogen content in shielding gas being less than 1%.2) The quantity of absorbed nitrogen decreases in the REM bearing weld metal, which yields the improvement of toughness in it.3) It was deduced that the decrease of nitrogen in the REM bearing weld metal was attributed to the decrease of its absorption rate due to the formation of REM oxide film or absorbed layer of REM on the surface of the molten pool.
{"title":"Improvement of Toughness in the Weld Metal of High Purity 30Cr-2Mo Steel by Addition of REM : Study on Welding Metallurgy in High Purity Ferritic Stainless Steels (Report 2)","authors":"Y. Nakao, K. Nishimoto, M. Terashima","doi":"10.2207/QJJWS1943.50.508","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.508","url":null,"abstract":"Effect of REM addition on the toughness in the weld metal of high purity 30Cr-2Mo steel was investigated. Welding was carried out by TIG method using deliberately contaminated argon with various ratio of nitrogen or air as shielding gas in order to vary the toughness of weld metals. The toughness of weld metals was evaluatedd using sub-size Charpy V-notch specimens with thickness of 3 mm. The main results obtained in this study are as follows;1) The toughness of the weld metal is significantly improved by addition of REM. Effective content of REM ranges from about 50 ppm to 200 ppm when nitrogen content in shielding gas being less than 1%.2) The quantity of absorbed nitrogen decreases in the REM bearing weld metal, which yields the improvement of toughness in it.3) It was deduced that the decrease of nitrogen in the REM bearing weld metal was attributed to the decrease of its absorption rate due to the formation of REM oxide film or absorbed layer of REM on the surface of the molten pool.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129458600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-10-01DOI: 10.2207/QJJWS1943.50.525
Kimiyuki Nishiguihi, T. Ohji, H. Koga
The molten pool surface profile in arc welding has been analyzed numerically by a finite difference method.In the first part of this report, the numerical method has been discussed and it is made clear that an iterative method of finite difference is useful to solve the non-linear partial differential equation which describes the molten pool surface profile.In the second part, the iterative method has been applied to some typical problems in arc welding and satisfactory results have been obtained.From these numerical analyses, it is concluded that the method, used in this work, is quite available for further investigation of molten pool phenomena in arc welding.
{"title":"Study on Behaviour of Molten Pool in Arc Welding (2nd Report) : Numerical Analysis of Molten Pool Surface Profile","authors":"Kimiyuki Nishiguihi, T. Ohji, H. Koga","doi":"10.2207/QJJWS1943.50.525","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.525","url":null,"abstract":"The molten pool surface profile in arc welding has been analyzed numerically by a finite difference method.In the first part of this report, the numerical method has been discussed and it is made clear that an iterative method of finite difference is useful to solve the non-linear partial differential equation which describes the molten pool surface profile.In the second part, the iterative method has been applied to some typical problems in arc welding and satisfactory results have been obtained.From these numerical analyses, it is concluded that the method, used in this work, is quite available for further investigation of molten pool phenomena in arc welding.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126443133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-10-01DOI: 10.2207/QJJWS1943.50.398
Shigeo Akashi, Mitsuhiro Natsume, M. Fukuzawa
The brittle fracture from a weld defect of through-thickness type (crack length 2a=10-30 mm) for mild steel, which had relatively low toughness, was investigated and compared with the behavior of base metal with machined notch. Results are summarized as follows:1) In bending COD tests, δc(-10)=0.3 mm and δc(-40)=0.2 mm were obtained for a weld defect notch on the manual arc welding. While for the same notch on non-gas arc welding, δc(-10)=0.3 mm and S δc(-40)=0.09 mm were obtained. For the latter, COD characteristic depended well on the temperature.2) In tensile tests on notched specimen of welded joint and base metal at -10°C and -40°C, low stress fracture did not occur and overall strain el exceeded yielding strain ey. But the value of e1 for welded joint was larger than that for base metal. In welded joints, the yielding of parent metal adjacent to weld occured preceding to yielding in the net ligament of weld metal which had higher yielding stress than parent metal. Consequently, for these overmatched joints the Burdekin's design curve gave a conservative estimate in the yielding range.
研究了韧性较低的低碳钢透厚型焊缝缺陷(裂纹长度2a=10 ~ 30mm)的脆性断裂行为，并与带机加工缺口的母材进行了比较。结果表明:1)在弯曲COD试验中，手工弧焊焊缝缺陷缺口的δc(-10)=0.3 mm， δc(-40)=0.2 mm。而在非气体弧焊上，相同缺口的δc(-10)=0.3 mm, S δc(-40)=0.09 mm。2)在-10℃和-40℃条件下，对焊接接头和母材的缺口试样进行拉伸试验，均未出现低应力断裂，总应变el超过屈服应变ey。但焊接接头的e1值大于母材。在焊接接头中，焊缝金属的屈服应力比焊缝金属的高，焊缝金属网带的屈服先于焊缝附近的母材屈服。因此，对于这些过匹配节点，伯德金设计曲线在屈服范围内给出了保守估计。
{"title":"Study on Brittle Fracture Initiation from Weld Defect (Second Report) : Fracture from Notch of Poor Penetration Type","authors":"Shigeo Akashi, Mitsuhiro Natsume, M. Fukuzawa","doi":"10.2207/QJJWS1943.50.398","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.398","url":null,"abstract":"The brittle fracture from a weld defect of through-thickness type (crack length 2a=10-30 mm) for mild steel, which had relatively low toughness, was investigated and compared with the behavior of base metal with machined notch. Results are summarized as follows:1) In bending COD tests, δc(-10)=0.3 mm and δc(-40)=0.2 mm were obtained for a weld defect notch on the manual arc welding. While for the same notch on non-gas arc welding, δc(-10)=0.3 mm and S δc(-40)=0.09 mm were obtained. For the latter, COD characteristic depended well on the temperature.2) In tensile tests on notched specimen of welded joint and base metal at -10°C and -40°C, low stress fracture did not occur and overall strain el exceeded yielding strain ey. But the value of e1 for welded joint was larger than that for base metal. In welded joints, the yielding of parent metal adjacent to weld occured preceding to yielding in the net ligament of weld metal which had higher yielding stress than parent metal. Consequently, for these overmatched joints the Burdekin's design curve gave a conservative estimate in the yielding range.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134080793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1981-07-05DOI: 10.2207/QJJWS1943.50.367
K. Seo, H. Hirano, K. Satoh
The present research deals with the fracture behavior and the strength of welded joints such as a side fillet welded joint which is loaded parallel to the axis of the weld at low temperature.In this paper, the effect of temperature on the fracture behavior in these welded joints are investigated experimentally.Experiments are made with five types of welded specimen in a temperature range from 20°C to -170°C. In the series of experiment, the results obtained are as follows:1) Three different types of fracture mode are appeared according to the different temperature.2) It is cleared that the critical shear displacement which depends on temperature can be applied as the engineering fracture criteria for fracture of these welded joints.3) In these welded joints, small scale of fractures of weld metal by shear force at low temperature induce the fatal brittle fracture of base metal.
{"title":"Strength of the Welded Joints on which Shear Force is Applied at Low Temperature (Part II) : Effect of throat Depth Weld Length","authors":"K. Seo, H. Hirano, K. Satoh","doi":"10.2207/QJJWS1943.50.367","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.367","url":null,"abstract":"The present research deals with the fracture behavior and the strength of welded joints such as a side fillet welded joint which is loaded parallel to the axis of the weld at low temperature.In this paper, the effect of temperature on the fracture behavior in these welded joints are investigated experimentally.Experiments are made with five types of welded specimen in a temperature range from 20°C to -170°C. In the series of experiment, the results obtained are as follows:1) Three different types of fracture mode are appeared according to the different temperature.2) It is cleared that the critical shear displacement which depends on temperature can be applied as the engineering fracture criteria for fracture of these welded joints.3) In these welded joints, small scale of fractures of weld metal by shear force at low temperature induce the fatal brittle fracture of base metal.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128077825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1981-04-01DOI: 10.2207/QJJWS1943.50.409
M. Hamasaki, Fumikazu Tateiwa
The authors have developed a consumable electrode water jet cutting technique as a underwater cutting method. Underwater cuttings of mild steel and aluminum were at this time carried out at a water depth up to 200 m. Welding machine and electrode wire used were DC constant voltage characteristic and 2.4 mm diam. steel wire. Cutting result at a deep water depth obtained was the same that at a shallow water depth, in case no load voltage was heightend 0.5-1.0 v every 10 m deep with increasing of water depth.Underwater cutting of mild steel by aluminum wire was also achieved at water depth up to 90 m. The dross was not recognized at cut surface, which was better than that by steel wire.
{"title":"Underwater Cutting Using a Consumable Electrode Water Jet Technique at a Deep water Depth","authors":"M. Hamasaki, Fumikazu Tateiwa","doi":"10.2207/QJJWS1943.50.409","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.409","url":null,"abstract":"The authors have developed a consumable electrode water jet cutting technique as a underwater cutting method. Underwater cuttings of mild steel and aluminum were at this time carried out at a water depth up to 200 m. Welding machine and electrode wire used were DC constant voltage characteristic and 2.4 mm diam. steel wire. Cutting result at a deep water depth obtained was the same that at a shallow water depth, in case no load voltage was heightend 0.5-1.0 v every 10 m deep with increasing of water depth.Underwater cutting of mild steel by aluminum wire was also achieved at water depth up to 90 m. The dross was not recognized at cut surface, which was better than that by steel wire.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123864121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1981-04-01DOI: 10.2207/QJJWS1943.50.161
A. Ohta, E. Sasaki, Masahide Kamakura, Masatoshi Nihei, M. Kosuge, Masao Kanao, M. Inagaki
The fatigue crack propagation rate and the stress intensity threshold level were measured on welded joints which were made by three kinds of welding processes, manual arc welding with covered electrode, gas metal arc welding, and submarged arc welding. The specimens were 200 mm wide center notched type. The material was a SM50B steel 20 mm in thickness. The fatigue crack propagation properties of the weld metal and the heat affected zone of these welded joints were found to be quite similar to each other and inferior to that of the base metal. The stress intensity threshold level of welded joints was about one fourth of that of the base metal. It is assumed that the inferiority of welded joints in crack propagation properties may be caused from the tensile residual stresses distributed in the middle part of the specimens. The removal of the tensile residual stresses by postweld heat treatment could improve welded joints in the fatigue crack propagation properties. The fatigue crack propagation properties and the stress intensity threshold level of welded joints after the postweld heat treatment are similar to those of the base metal.
{"title":"Effect of Residual Tensile Stresses on Threshold Level for Fatigue Crack Propagation in Welded Joints of SM50B Steel","authors":"A. Ohta, E. Sasaki, Masahide Kamakura, Masatoshi Nihei, M. Kosuge, Masao Kanao, M. Inagaki","doi":"10.2207/QJJWS1943.50.161","DOIUrl":"https://doi.org/10.2207/QJJWS1943.50.161","url":null,"abstract":"The fatigue crack propagation rate and the stress intensity threshold level were measured on welded joints which were made by three kinds of welding processes, manual arc welding with covered electrode, gas metal arc welding, and submarged arc welding. The specimens were 200 mm wide center notched type. The material was a SM50B steel 20 mm in thickness. The fatigue crack propagation properties of the weld metal and the heat affected zone of these welded joints were found to be quite similar to each other and inferior to that of the base metal. The stress intensity threshold level of welded joints was about one fourth of that of the base metal. It is assumed that the inferiority of welded joints in crack propagation properties may be caused from the tensile residual stresses distributed in the middle part of the specimens. The removal of the tensile residual stresses by postweld heat treatment could improve welded joints in the fatigue crack propagation properties. The fatigue crack propagation properties and the stress intensity threshold level of welded joints after the postweld heat treatment are similar to those of the base metal.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133749417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1976-04-01DOI: 10.2534/JJASNAOE1968.1975.138_461
K. Nagai, K. Kajimoto
A series of research so far carried out, has clarified that among various kinds of multiple notches existing in steel structures, the collinear notch has the largest influence upon brittle fracture initiations. In this research, therefore, the collinear notch is taken up as the subject of study, and examination is made on deformation behaviors ahead of notch tip and on fracture characteristics by elastic-plastic analysis based on the finite element method (FEM) and by experiments.The results are summarized as follows : (1) A crack opening displacement (COD) obtained by FEM is approximately equal to the theoretical value by E. Smith and a measured value by Moire method, which enables the coefficient of interaction effects of notches to be estimated by FEM.(2) When notches are contiguous very closely to each other, fracture stress is decreased and at the same time the critical COD is decreased. Therefore the concept of COD is not simply applicable to that case. The reason for the occurrence of such phenomenon is clarified through examination of the relation between the plastic strain in notch tip zone and the COD which are respectively calculated by FEM.
{"title":"Deformation Behaviors and Fracture Characteristics in Plate Containing Two Collinear Notches","authors":"K. Nagai, K. Kajimoto","doi":"10.2534/JJASNAOE1968.1975.138_461","DOIUrl":"https://doi.org/10.2534/JJASNAOE1968.1975.138_461","url":null,"abstract":"A series of research so far carried out, has clarified that among various kinds of multiple notches existing in steel structures, the collinear notch has the largest influence upon brittle fracture initiations. In this research, therefore, the collinear notch is taken up as the subject of study, and examination is made on deformation behaviors ahead of notch tip and on fracture characteristics by elastic-plastic analysis based on the finite element method (FEM) and by experiments.The results are summarized as follows : (1) A crack opening displacement (COD) obtained by FEM is approximately equal to the theoretical value by E. Smith and a measured value by Moire method, which enables the coefficient of interaction effects of notches to be estimated by FEM.(2) When notches are contiguous very closely to each other, fracture stress is decreased and at the same time the critical COD is decreased. Therefore the concept of COD is not simply applicable to that case. The reason for the occurrence of such phenomenon is clarified through examination of the relation between the plastic strain in notch tip zone and the COD which are respectively calculated by FEM.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1976-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116683922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Insert-type Electron Beam Welding Technology (Report 1) : Characteristics of Insert-type Welding","authors":"Y. Arata, K. Terai, H. Nagai, Iwao Futami, S. Shimizu, T. Aota","doi":"10.2207/QJJWS1943.43.931","DOIUrl":"https://doi.org/10.2207/QJJWS1943.43.931","url":null,"abstract":"6mmおよび12mm厚さの2 1/4Cr-1Mo鋼(ASTMF 22)とオーステナイト系ステンレス鋼(AISI 316)の異材継手および炭素鋼(SM 41A)の同材継手について,インサート型電子ビーム溶接による適正裏波溶接条件選定を目的とした諸試験を行なった結果,次の結論を得た.1)最大溶込み深さ部近傍における溶接部の諸特性のうち,スパイク現象については,最大スパイク長さが1.5mm以下のものが全体の約80%を占め,それを越える長さのスパイクの発生頻度は急激に減少する.また,ペネトロパラメータPpが約6以上になると,1.5mmをこえる長さのスパイクが発生し易い.なお,ビード断面形状については,溶込み部先端が極端に細いクサビ(Wedge)型ビードを形成する.いっぽう,最大溶込み深さ部以外における溶接部の諸特性のうち,スパイク現象については,1.5mmをこえる長さのスパイクが発生し始めるPp,sはab>0.90のときPp,s>6,ab≈0.90でPp,s≈6,ab 0.90の場合はビード断面形状は井戸(Well)型に近く,ab≦0.90の場合はクサビ(Wedge)型に近い.2)インサート型電子ビーム溶接法による裏波溶接においては,インサートメタルの幅以上の断面ビード幅を有し,スパイク現象の発生が少なく,表面および裏面部のビード幅がほぼ等しいような井戸型ビード断面形状の得られる溶接条件を選定しなければならない.このような条件を満足するabはほぼ1.20前後である.また継手形状としては,ルートスペースを有する継手形状を採用することにより,裏波溶接が容易になる.また,良好な表面および裏波ビードを得るためには,ビード断面形状および余盛高さの観点より,インサートメタルの高さを継手部の厚さにほぼ等しくなるように選定することが望ましい。3)ルートスペースを有する継手形状を採用することにより,適正溶接条件範囲が広くなり,板厚が増大するにつれてその有効性は著しくなる.その場合の裏波ビード形成機構は対流型に近づく.また,管の溶接の場合において問題となるスパッタについても,ルートスペースを付すことにより,著しく減少し,実用的価値が高い.4)脱酸不十分な炭素鋼の同材継手において,インサートメタルを使用しない場合には欠陥の発生は著しい.しかし,強脱酸性を有するアルミキルド鋼のインサートメタルを使用した場合にはインサートキャップ高さ(またはインサートメタル高さ)または断面積が増大するに従って溶接部に発生する欠陥は減少する。","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1973-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114621291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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