摘要
利用有限元法,对Q345R钢焊后热处理进行模拟分析.结果表明,焊态残余应力在焊缝和热影响区具有较高的应力水平,远离焊缝热影响区,应力逐渐降低.热处理后,残余应力降低了近60%,最大值位于热影响区浅表区域.热处理不仅使应力降低,同时使得应力发生再分布,母材热处理后应力增加.热处理过程中,随着温度升高,屈服强度降低,材料发生塑性变形使得应力释放,高温下残余应力基本降为0.在降温过程中,材料屈服强度增加,导致应力回升,热处理态残余应力主要在降温过程中产生.随着热处理温度升高,最大残余应力降低,超过600℃后保持不变,因此热处理温度在600℃左右较为合适.
The post-welding heat treatment(PWHT) is simulated by finite element method.The results show that large as-weld residual stress is generated in the weld metal and heat-affected zone(HAZ),and is decreased gradually far away the HAZ.After PWHT,the residual stress is decreased about 60%.PWHT not only decreases the residual stress,but also makes the residual stress re-distributed.The stress re-distribution makes the stress in base metal increase.During the heating of PWHT,the yield strength is decreased and the plastic deformation is generated,which leads to the relaxation of residual stress.During the cooling of PWHT,the yield strength is increased,which makes the stress increase.The residual stress after PWHT is mainly generated during the cooling of PWHT.The maximum residual stress is increased with the PWHT temperature increase,but keeps stable above 600 ℃.Therefore a suitable temperature of 600 ℃ could be used in PWHT for Q345R steel.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2011年第4期45-48,115,共4页
Transactions of The China Welding Institution
基金
山东省自然科学基金资助项目(ZR2010AQ002
Y2008F38)
中央高校基本科研业务费专项资金资助项目(10CX04030A
09CX04041A)
江苏省工业装备数字制造及控制技术重点实验室开放研究基金资助项目(2010)
关键词
焊接残余应力
焊后热处理
有限元
welding residual stress
post-welding heat treatment
finite element
