摘要
采用热模拟方法，对ＥＨ３６ＭＯＤ钢焊接热影响区粗晶区（ＣＧＨＡＺ）的相变超塑性及其对疲劳寿命的影响进行了研究。研究结果证明：（１）采用热作用与拘束位移的方法，在模拟ＣＧＨＡＺ中确实存在着相变超塑性现象；（２）该超塑性应变值为１．０％时，其ＣＧＨＡＺ的疲劳寿命比无相变超塑性的提高了１９％；（３）微观分析表明，前者Ｍ—Ａ组元的形态为长条状与块状的混合体，其分布为铁素体（Ｆ）基体包围Ｍ—Ａ组元和Ｍ—Ａ组元包围Ｆ基体的两种并存特征，而后者Ｍ—Ａ组元的形态呈单一的长条状，其分布仅为Ｍ—Ａ组元包围Ｆ基体；（４）Ｆ包围Ｍ—Ａ属软相包围硬相，在疲劳断裂过程中Ｆ基体内因滑移受阻所产生的微区应力小于Ｍ—Ａ包围Ｆ的，从而减慢了疲劳裂纹扩展速率，提高了疲劳寿命。
The transformation superplasticity in welding CGHAZ(Coarse Grain Heat Affected Zone)of EH36MOD steel and its effect on fatigue life have been studied with thermal simulating method. Experimental results evidenced that(1)the transformation superplasticity phenomena do exist in the simulated CGHAZ by using restrained displacement;(2)the fatigue life of the CGHAZ is increased by 19% with increasing the superplasticity strain from 0% (no transformation superplasticity) to 1.0%;(3)in the case of 1.0 % strain,the M-A constituent is a striped-massive mixed morphology,but in the case of 0% strain,the M-A constituent is of single striped form;(4) of the above two cases,the former micro-region stress,which was caused by the slip resistance of ferrite matrix,is smaller than that of the latter during fatigue fracture process,the former fatigue life is longer than the latter.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
1996年第1期49-55,共7页
Transactions of The China Welding Institution
基金
国家自然科学基金
关键词
相变
超塑性
疲劳
断裂
焊接
热影响区
粗晶区
s:transformation superplasticity,M-A constituent,fatigue fracture
