基于深度敏感压痕研究高温时效对HR3C/T92异种钢焊接接头局部力学性能的影响

DSI-based Studies of the Effects of High-temperature Aging on Local Mechanical Properties of HR3C/T92 Dissimilar Steel Welded Joint

应用深度敏感压痕技术(DSI)研究了高温时效对HR3C/T92焊接接头局部力学性能的影响。通过引入压痕特征参量来表征焊接接头各区域的强度、塑性与韧性,采用Oliver和Pharr方法计算弹性模量,并结合微观组织结构演化对时效后HR3C/T92焊接接头局部力学性能的变化进行了分析。结果表明:高温时效后,HR3C侧与焊缝的强度增强,塑性与韧性下降,但在T92一侧,力学性能的变化与之相反;高温时效后,HR3C侧与焊缝中析出大量的第二相粒子;在T92一侧,马氏体板条出现回复,位错出现湮灭。

In this paper,depth-sensing indentation(DSI)testing was used to study the effect of long-term high-temperature aging on local mechanical properties of HR3C/T92 dissimilar welded joints.The strength,ductility and toughness in particular zones of the welded joints were characterized by employing indentation characteristic parameters,and the elastic modulus was calculated by using Oliver and Pharr method.The change of local mechanical properties of HR3C/T92 was also analyzed by observing the microstructural evolution.The results show that,after the high-temperature aging,the strength in the HR3C side and weld metal became increased but the ductility and toughness in these zones decreased,while in the T92 side,a contrary tendency was found;in addition,after the hign-temp-eratore aging,extensive second phase particles become precipitated in HR3C and weld metal;and in the T92 side,the recovery of martensitic laths and the disappearance of dislocations were also observed.