Toshimi Matsurnoto, M. Tsukamoto, F. Suzuki, Y. Wadayama, H. Satoh
In a Power Fusion Reactor, a huge megnetic field is necessary for plasma confinement. This field also interacts with the high current to produce large forces tending to deform the superconducting cables ; this electro-magnetic force demands very high values of the cryogenic yield strength and fracture toughness in the supporting structural materials. It is said to be difficult to develop welds satisfing the same criteria as for the structural material. It is useful to investigate the usability of welded joint with a lower yield strength than the base metal, but associated with a higher fracture toughness.From this viewpoint, the influence of the undermatched joint on the deformation and the stressstrain property of the coil case was investigated by using a finite element method. It is concluded that (1) there is only a slight difference in the overall deformation of the coil case whether the undermatched joint is included in the calculation or not, (2) the maximum strain and the muximum plastic strain at the undermatched welds can be controlled to be less than those in the base metal with a judicious choice of weld location and yield strength level of welds.
{"title":"Investigations on Usability of Undermatched Joint in a Superconducting Coil Case for Fusion Reactor","authors":"Toshimi Matsurnoto, M. Tsukamoto, F. Suzuki, Y. Wadayama, H. Satoh","doi":"10.2207/QJJWS.9.575","DOIUrl":"https://doi.org/10.2207/QJJWS.9.575","url":null,"abstract":"In a Power Fusion Reactor, a huge megnetic field is necessary for plasma confinement. This field also interacts with the high current to produce large forces tending to deform the superconducting cables ; this electro-magnetic force demands very high values of the cryogenic yield strength and fracture toughness in the supporting structural materials. It is said to be difficult to develop welds satisfing the same criteria as for the structural material. It is useful to investigate the usability of welded joint with a lower yield strength than the base metal, but associated with a higher fracture toughness.From this viewpoint, the influence of the undermatched joint on the deformation and the stressstrain property of the coil case was investigated by using a finite element method. It is concluded that (1) there is only a slight difference in the overall deformation of the coil case whether the undermatched joint is included in the calculation or not, (2) the maximum strain and the muximum plastic strain at the undermatched welds can be controlled to be less than those in the base metal with a judicious choice of weld location and yield strength level of welds.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134508382","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}
In this paper, the influence of plate thickness on the fatigue strength of non-load-carrying fillet weld joints is examined both experimentally and analytically, from the view point of weld residual stresses.In order to control the longitudinal residual stresses (in the direction of the weld line), rib-cruciform joint specimens with various plate width were prepared. On the one hand, specimens of which heat input for each pass was varied were also prepared to control the transverse residual stresses (in the perpendicular direction to the weld line). Using these specimens, both residual stress measurement and fatigue tests were carried out.It was found that the plate width of specimen had great effects on the longitudinal residual stresses and little effect on the transverse residual stresses respectively. And it was also found that the transverse residual stresses increased as the heat input decreased.As far as the heat input was constant, the plate width had no effect on the fatigue strength. On the other hand, the heat input significantly influenced the fatigue strength of joints with a same thickness of main plate. That was, the fatigue strength in the case of high heat input was much higher than in the case of low heat input.From above results, it is concluded that the fatigue strength of non-load-carrying fillet weld joints depends on the transverse residual stresses and that the tensile residual stresses increase as the plate thickness increases and/or the heat input decreases, causing the reduction of the fatigue strength.
{"title":"Influence of Residual Stress on Fatigue Strength of Non-load-carrying Fillet Weld Joints","authors":"K. Matsuoka, I. Takahashi, T. Yoshii, E. Fujii","doi":"10.2207/QJJWS.9.36","DOIUrl":"https://doi.org/10.2207/QJJWS.9.36","url":null,"abstract":"In this paper, the influence of plate thickness on the fatigue strength of non-load-carrying fillet weld joints is examined both experimentally and analytically, from the view point of weld residual stresses.In order to control the longitudinal residual stresses (in the direction of the weld line), rib-cruciform joint specimens with various plate width were prepared. On the one hand, specimens of which heat input for each pass was varied were also prepared to control the transverse residual stresses (in the perpendicular direction to the weld line). Using these specimens, both residual stress measurement and fatigue tests were carried out.It was found that the plate width of specimen had great effects on the longitudinal residual stresses and little effect on the transverse residual stresses respectively. And it was also found that the transverse residual stresses increased as the heat input decreased.As far as the heat input was constant, the plate width had no effect on the fatigue strength. On the other hand, the heat input significantly influenced the fatigue strength of joints with a same thickness of main plate. That was, the fatigue strength in the case of high heat input was much higher than in the case of low heat input.From above results, it is concluded that the fatigue strength of non-load-carrying fillet weld joints depends on the transverse residual stresses and that the tensile residual stresses increase as the plate thickness increases and/or the heat input decreases, causing the reduction of the fatigue strength.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132083501","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}
Y. Suita, M. Toyoda, T. Hirano, Kazumasa Kusanagi, S. Nakamura, Yoshihiro Yamamoto, H. Mitani
This paper is concerned with the theoretical evaluation of residual stresses in multilayered structures fabricated on substrates, such as evaporated films and plating films.Firstly, the analysis of thermal stresses in multilayered elastic thin films is carried out by using the method of strain suppression. Next, the theoretical formulas for evaluation of residual stresses arising in thin films and substrates are derived by the use of combining the results of the thermal stress analysis and those of stresses due to the inherent strains of the thin film. Furthermore the controlling parameters of residual stresses are derived theoretically.Experimental results of residual stresses in evaporated Ag films and hard chrominum plating films agree approximately with theoretical ones.
{"title":"Analysis of residual stresses in evaporated and plating films","authors":"Y. Suita, M. Toyoda, T. Hirano, Kazumasa Kusanagi, S. Nakamura, Yoshihiro Yamamoto, H. Mitani","doi":"10.2207/QJJWS.7.543","DOIUrl":"https://doi.org/10.2207/QJJWS.7.543","url":null,"abstract":"This paper is concerned with the theoretical evaluation of residual stresses in multilayered structures fabricated on substrates, such as evaporated films and plating films.Firstly, the analysis of thermal stresses in multilayered elastic thin films is carried out by using the method of strain suppression. Next, the theoretical formulas for evaluation of residual stresses arising in thin films and substrates are derived by the use of combining the results of the thermal stress analysis and those of stresses due to the inherent strains of the thin film. Furthermore the controlling parameters of residual stresses are derived theoretically.Experimental results of residual stresses in evaporated Ag films and hard chrominum plating films agree approximately with theoretical ones.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128319599","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}
The effect of δ ferrite morphology and grain boundary property on the low temperature toughness of austenitic stainless steel SUS304L weld metal has been studied. The types of δ ferrite were classified into three categories : vermicular, lacy, and globular. When Charpy test were performed at low temperature, brittle fracture easily occurred in a vermicular type δ ferrite because the longitudinal direction of this δ perallel to [100]δ, that is a cleavage plain.On the other hand, brittle fracture scarcely occurred in both a globular type and a lacy type δ ferrite, because the the stress concentration must be low at globular type δ and the Kurdjumov-Sachs (K-S) relationship holds between lacy type δ and γ phase. Grain boundary holding the K-S are coherence to grains and hardly cause the decohesion.The present data indicate that changing the δ ferrite morphology from a vermicular type to lacy type prevents the cleavage fracture and increases the fracture toughness at low temperature.
{"title":"The Effects of .DELTA.-Ferrite Morphology on Low Temperature Fracture Toughness of Austenitic Stainless Steel Weld Metal.","authors":"O. Kamiya, K. Kumagai, Y. Kikuchi","doi":"10.2207/qjjws.9.525","DOIUrl":"https://doi.org/10.2207/qjjws.9.525","url":null,"abstract":"The effect of δ ferrite morphology and grain boundary property on the low temperature toughness of austenitic stainless steel SUS304L weld metal has been studied. The types of δ ferrite were classified into three categories : vermicular, lacy, and globular. When Charpy test were performed at low temperature, brittle fracture easily occurred in a vermicular type δ ferrite because the longitudinal direction of this δ perallel to [100]δ, that is a cleavage plain.On the other hand, brittle fracture scarcely occurred in both a globular type and a lacy type δ ferrite, because the the stress concentration must be low at globular type δ and the Kurdjumov-Sachs (K-S) relationship holds between lacy type δ and γ phase. Grain boundary holding the K-S are coherence to grains and hardly cause the decohesion.The present data indicate that changing the δ ferrite morphology from a vermicular type to lacy type prevents the cleavage fracture and increases the fracture toughness at low temperature.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128328302","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}
M. Aritoshi, K. Okita, T. Enjo, K. Ikeuchi, F. Matsuda
The microstructure and bond strength of the friction-welded joint of Al (commercially pure aluminum) to OFC (oxygen free copper) have been investigated in order to understand the formation of intermetallic compounds and its effects on the mechanical properties of the joint. A mixing layer of Al and Cu which showed a fine stratified microstructure was formed in Al adjacent to the weld interface by mechanical picking-up of Cu into Al. In the mixing layer, intermetallic compounds CuAl2, CuAl and Cu9Al4 were detected by X-ray diffraction analyses and TEM. As forge pressure P2 was increased, the width of the mixing layer was decreased and the stratified microstructure became considerably isolated flaky one. The tensile strength of the joint was increased as P2 was increased, and at P2 above 120 MPa the joints were fractured in the heat affected zone of Al. On the other hand, the joints welded at P2 below 80 MPa were fractured mainly in the mixing layer. EDX analyses of the area around cracks suggested that the crack on the tensile test initiated at CuAl in the mixing layer, since the composition around the initiation site of the crack corresponded approximately to that of CuAl. From these results, it can be concluded that the intermetallic compounds, especially CuAl have harmful effects on the mechanical properties of the joint. The increase in the joint strength with rise in P2 can be explained as a consequence of the decrease in the thickness of the mixing layer which includes a number of fine intermetallic compound layers. The formation of mixing layer having the fine stratified microstructure is probably due to the mechanical mixing in the solid state, since the average temperature of frictionn interface estimated from the thermoelectric power between Cu and Al was below the lowest eutectic temperature of the Cu-Al system.
{"title":"Friction Welding of Oxygen Free Copper to Pure Aluminum","authors":"M. Aritoshi, K. Okita, T. Enjo, K. Ikeuchi, F. Matsuda","doi":"10.2207/qjjws.9.467","DOIUrl":"https://doi.org/10.2207/qjjws.9.467","url":null,"abstract":"The microstructure and bond strength of the friction-welded joint of Al (commercially pure aluminum) to OFC (oxygen free copper) have been investigated in order to understand the formation of intermetallic compounds and its effects on the mechanical properties of the joint. A mixing layer of Al and Cu which showed a fine stratified microstructure was formed in Al adjacent to the weld interface by mechanical picking-up of Cu into Al. In the mixing layer, intermetallic compounds CuAl2, CuAl and Cu9Al4 were detected by X-ray diffraction analyses and TEM. As forge pressure P2 was increased, the width of the mixing layer was decreased and the stratified microstructure became considerably isolated flaky one. The tensile strength of the joint was increased as P2 was increased, and at P2 above 120 MPa the joints were fractured in the heat affected zone of Al. On the other hand, the joints welded at P2 below 80 MPa were fractured mainly in the mixing layer. EDX analyses of the area around cracks suggested that the crack on the tensile test initiated at CuAl in the mixing layer, since the composition around the initiation site of the crack corresponded approximately to that of CuAl. From these results, it can be concluded that the intermetallic compounds, especially CuAl have harmful effects on the mechanical properties of the joint. The increase in the joint strength with rise in P2 can be explained as a consequence of the decrease in the thickness of the mixing layer which includes a number of fine intermetallic compound layers. The formation of mixing layer having the fine stratified microstructure is probably due to the mechanical mixing in the solid state, since the average temperature of frictionn interface estimated from the thermoelectric power between Cu and Al was below the lowest eutectic temperature of the Cu-Al system.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134486209","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}
Round bar tension test, Charpy V impact test and static 3-point bending test as well as ultrasonic attenuation and wave velocity measurements are made by using carbon steel heat treated with various conditions. Those tests are carried out for the purpose of establishing the nondestructive methods for material property characterization. Correlations between results of material tests and ultrasonic attenuation or wave velocity are examined.Relationships between yield strength, ultimate strength or elongation percentage and attenuation coefficient are represented by smooth curves. Yield strength as well as ultimate strength decreases and elongation percentage increases with increasing attenuation coefficient. Relationship between Charpy V notch impact energy absorption in the upper shelf region and wave velocity is represented approximately by a straight line. Upper shelf energy absorption increases with increasing velocity. Relationship between critical COD and attenuation coefficient is represented roughly by a straight line. Critical COD increases with increasing attenuation coefficient. Using the results above mentioned, mechanical properties such as strength, elongation and fracture toughness can be estimated nondestructively from ultrasonic attenuation or wave velocity.
{"title":"Inference of mechanical properties in heat treated steel from ultrasonic attenuation and velocity measurements.","authors":"I. Oda","doi":"10.2207/QJJWS.5.550","DOIUrl":"https://doi.org/10.2207/QJJWS.5.550","url":null,"abstract":"Round bar tension test, Charpy V impact test and static 3-point bending test as well as ultrasonic attenuation and wave velocity measurements are made by using carbon steel heat treated with various conditions. Those tests are carried out for the purpose of establishing the nondestructive methods for material property characterization. Correlations between results of material tests and ultrasonic attenuation or wave velocity are examined.Relationships between yield strength, ultimate strength or elongation percentage and attenuation coefficient are represented by smooth curves. Yield strength as well as ultimate strength decreases and elongation percentage increases with increasing attenuation coefficient. Relationship between Charpy V notch impact energy absorption in the upper shelf region and wave velocity is represented approximately by a straight line. Upper shelf energy absorption increases with increasing velocity. Relationship between critical COD and attenuation coefficient is represented roughly by a straight line. Critical COD increases with increasing attenuation coefficient. Using the results above mentioned, mechanical properties such as strength, elongation and fracture toughness can be estimated nondestructively from ultrasonic attenuation or wave velocity.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123673685","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}
Effects of melting conditions and atmospheres on the nitrogen absorption of tungsten arc-melted iron and stainless steel were studied. With the increase of the arc current, the nitrogen content of the melted stainless steel decreases, while that of the melted iron is nearly constant. In both of the two melted metals, the nitrogen content depends hardly on the specimen weight and the gas flow rate. In each of them, the nitrogen content increases with the melting time and then reaches the saturated value which increases with the nitrogen partial pressure of atmosphere. The nitrogen absorption of the arc-melted metal was discussed with equilibrium data and was compared with the gas tungsten arc weld metal.
{"title":"The nitrogen absorption of arc-melted iron and stainless steel.","authors":"T. Kuwana, H. Kokawa","doi":"10.2207/QJJWS.5.497","DOIUrl":"https://doi.org/10.2207/QJJWS.5.497","url":null,"abstract":"Effects of melting conditions and atmospheres on the nitrogen absorption of tungsten arc-melted iron and stainless steel were studied. With the increase of the arc current, the nitrogen content of the melted stainless steel decreases, while that of the melted iron is nearly constant. In both of the two melted metals, the nitrogen content depends hardly on the specimen weight and the gas flow rate. In each of them, the nitrogen content increases with the melting time and then reaches the saturated value which increases with the nitrogen partial pressure of atmosphere. The nitrogen absorption of the arc-melted metal was discussed with equilibrium data and was compared with the gas tungsten arc weld metal.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123792685","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}
As Laser beam can be focused to pointed area, it is suitable to apply high speed welding of thin sheet metal. This experiment was carried out to know what advantage can be expected by applying Laser beam welding to surface coated steel sheet and austenitic stainless steel.The results obtained in this report are as follows;1) Steel sheet can be welded with much smaller distortion by Laser beam welding, compared with TIG welding. For coated sheet, Laser beam welding gives less damage to coated layer than that of TIG weld-ing. It is possible to make full penetration weld to use 3-5 times faster speed by Laser beam welding than by TIG welding.2) TIG weld metal of Zn coated sheet shows Zn rich region at surface but Laser weld metal does not.3) Laser beam welded joints of stainless steel show little weld decay tendency, which is almost same level as electron beam welded joint.
{"title":"Application of Laser Beam Welding to Thin Steel Sheet","authors":"I. Masumoto, T. Shinoda, Hiroyuki Ishiyama","doi":"10.2207/QJJWS.3.26","DOIUrl":"https://doi.org/10.2207/QJJWS.3.26","url":null,"abstract":"As Laser beam can be focused to pointed area, it is suitable to apply high speed welding of thin sheet metal. This experiment was carried out to know what advantage can be expected by applying Laser beam welding to surface coated steel sheet and austenitic stainless steel.The results obtained in this report are as follows;1) Steel sheet can be welded with much smaller distortion by Laser beam welding, compared with TIG welding. For coated sheet, Laser beam welding gives less damage to coated layer than that of TIG weld-ing. It is possible to make full penetration weld to use 3-5 times faster speed by Laser beam welding than by TIG welding.2) TIG weld metal of Zn coated sheet shows Zn rich region at surface but Laser weld metal does not.3) Laser beam welded joints of stainless steel show little weld decay tendency, which is almost same level as electron beam welded joint.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122976722","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}
T. Haramaki, M. Nakamura, Takao Funarnoto, T. Shida
A new barzing method was investigated in order to increase the strength of fusing joints of insulated copper wires. This process is a combination of fusing and brazing of brass terminal and insulated conner wires.The filler metal, the brass terminal and the wires were heated simultaneously by resistance heating, and they were bonded. The joint which was brazed at about 700°C using BCuP-5 (Cu-15%Ag-5%P) filler metal gave the best result. That joint fractured at the insulated copper wire (base metal) in tensile testing.A joint layer which consisted of mainly Cu, Ag, P and a little carbide was formed at the joint interface.
{"title":"Metallic Joining Technique of Insulated Copper Coil.","authors":"T. Haramaki, M. Nakamura, Takao Funarnoto, T. Shida","doi":"10.2207/QJJWS.9.223","DOIUrl":"https://doi.org/10.2207/QJJWS.9.223","url":null,"abstract":"A new barzing method was investigated in order to increase the strength of fusing joints of insulated copper wires. This process is a combination of fusing and brazing of brass terminal and insulated conner wires.The filler metal, the brass terminal and the wires were heated simultaneously by resistance heating, and they were bonded. The joint which was brazed at about 700°C using BCuP-5 (Cu-15%Ag-5%P) filler metal gave the best result. That joint fractured at the insulated copper wire (base metal) in tensile testing.A joint layer which consisted of mainly Cu, Ag, P and a little carbide was formed at the joint interface.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131546319","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}
Preheating is performed to prevent cold cracking in steel constructions. Preheating produces a good effect on cooling times, which are t8/5 (cooling time from 800°C to 500°C) related to the maximum hardness at HAZ, or which are t200, t150, t100 (tθ : cooling time from the solidification to θ) connected with the thermal factor. In the welding field, a whole member can not be preheated uniformly, and then local preheating near the weld line is generally performed.This report deals with local preheating and welding procedures of a butt joint and a corner joint. Predicted values of cooling times have been compared with the experimental data. The predicted values have been obtained by theoretical formulae. The results are summarized as follows :(1) Relation between cooling time and thermal factor, (ΣD·Δt)100 has been investigated. The thermal factor is correlated most closely with cooling time t150.(2) The predicted values of cooling time t8/5 and thermal factor (ΣD·Δt)100 have given good agreement with the experimental values.
{"title":"Estimation of the Cooling Time t8/5 and Thermal Factor of Weldments with Local Preheating.","authors":"T. Terasaki, K. Ishimoto","doi":"10.2207/QJJWS.9.436","DOIUrl":"https://doi.org/10.2207/QJJWS.9.436","url":null,"abstract":"Preheating is performed to prevent cold cracking in steel constructions. Preheating produces a good effect on cooling times, which are t8/5 (cooling time from 800°C to 500°C) related to the maximum hardness at HAZ, or which are t200, t150, t100 (tθ : cooling time from the solidification to θ) connected with the thermal factor. In the welding field, a whole member can not be preheated uniformly, and then local preheating near the weld line is generally performed.This report deals with local preheating and welding procedures of a butt joint and a corner joint. Predicted values of cooling times have been compared with the experimental data. The predicted values have been obtained by theoretical formulae. The results are summarized as follows :(1) Relation between cooling time and thermal factor, (ΣD·Δt)100 has been investigated. The thermal factor is correlated most closely with cooling time t150.(2) The predicted values of cooling time t8/5 and thermal factor (ΣD·Δt)100 have given good agreement with the experimental values.","PeriodicalId":273687,"journal":{"name":"Transactions of the Japan Welding Society","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131661938","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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