Peng HE
,
Jicai FENG
,
Jiecai HAN
,
Yiyu QIAN
材料科学技术（英文）
A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. The method of predicting maximum hardness Hv(y, z) and maximum inherent strain gmax is given. The model T.E.P-Tav-hardness calculation is proposed to predict distribution of inherent strains in T type welding structure. By T.E.P-Tav-hardness calculation, distribution of longitudinal inherent strains can be predicted in T type welding structure, and calculation and experimental results are consistent.
关键词:
Inherent strain
,
null
,
null
Peng HE
,
Jiuhai ZHANG
,
Toshio Terasake
,
Testuya Aliyama
材料科学技术（英文）
A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. The computing method of distribution of longitudinal inherent strains in multiple-passes welding in heavy plate weldment is proposed. Distribution of longitudinal inherent strains in one-pass welding and two-passes welding are compared and analyzed. The effect of cutting on inherent strain is discussed.
关键词:
Peng HE
,
Jiuhai ZHANG
,
Toshio Terasaki
,
Testuya Akiyama
材料科学技术（英文）
A fundamental theory for the analysis of residual welding stresses and deformation based on the inherent strain distribution along the welded joint is introduced. Distribution of inherent strains and longitudinal residual stresses in medium thickness plate weldment is calculated and analyzed. A new method of calculating inherent strains and longitudinal residual stresses is proposed.
关键词:
Peng HE
,
Jicai FENG
,
Heng ZHOU
材料科学技术（英文）
Brazing of Ti3Al alloys with the filler metal Cu-P was carried out at 1173~1273 K for 60~1800 s. When products are brazed, the optimum brazing parameters are as follows: brazing temperature is 1215~1225 K; brazing time is 250~300 s. Four kinds of reaction products were observed during the brazing of Ti3Al alloys with the filler metal Cu-P, i.e., Ti3Al phase with a small quantity of Cu (Ti3Al(Cu)) formed close to the Ti3Al alloy; the TiCu intermetallic compounds layer and the Cu3P intermetallic compounds layer formed between Ti3Al(Cu) and the filler metal, and a Cu-base solid solution formed with the dispersed Cu3P in the middle of the joint. The interfacial structure of brazed Ti3Al alloys joints with the filler metal Cu-P is Ti3Al/Ti3Al(Cu)/TiCu/Cu3P/Cu solid solution (Cu3P)/Cu3P/TiCu/Ti3Al(Cu)/Ti3Al, and this structure will not change with brazing time once it forms. The thickness of TiCu+Cu3P intermetallic compounds increases with brazing time according to a parabolic law. The activation energy Q and the growth velocity K0 of reaction layer TiCu+Cu3P in the brazed joints of Ti3Al alloys with the filler metal Cu-P are 286 kJ/mol and 0.0821 m2/s, respectively, and growth formula was y2=0.0821exp(-34421.59/T)t. Careful control of the growth for the reaction layer TiCu+Cu3P can influence the final joint strength. The formation of the intermetallic compounds TiCu+Cu3P results in embrittlement of the joint and poor joint properties. The Cu-P filler metal is not fit for obtaining a high-quality joint of Ti3Al brazed.
关键词:
Brazed joints
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null
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