奥氏体不锈钢熔敷金属结晶裂纹断口形貌及抗热裂性能
Fracture morphology of solidification crack and crack resisting property of austenitic stainless steel deposited metal
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摘要: 本文用横向可变拘束法,对不同合金系列的奥氏体不锈钢焊条的熔敷金属进行了试验,井用电镜,能谱对断口的形貌进行了观察分析,结果表明,抗热裂性能较差的熔敷金属断口形貌可由角形扩展成矩形。在温度、应变速率一定的条件下,通过调整Creq/Nieq比值,可显著地改变抗热裂性能,本文所研究的Cr29Ni19焊条的熔敷金属Creq/Nieq=1.7,且铁素体平均含量大于15%时,焊缝具有良好的抗热裂性能。Abstract: The deposited metals of austenitic stainless steel type covered electrode with different alloy system are tested by using Trans-varestraint test. Their fracture morphologies of cracks are observered with EPSA. The results show that when the crack-resisting capacity of deposited metal is poor the crack fracture morphologies appear a development from prism to rectangle.The content of ferrite in weld metal is one of important factors affecting the solidification carck sensibility of austentic stainless steels deposited metal. While the temperature and strain rate are constant the crack-resisting property can be obivously improved through changing the ratio of Creq/Nieq.The deposited metal of the Cr29Ni19 type covered electrode researched in this paper possesses better crackresisting property when its Creq/Nieq is 1.7 and its ferrite content is more than 15 pereent.