论文部分内容阅读
以R307耐热钢焊条为试验材料,研究了在不同道间温度下,其熔敷金属的微观组织和力学性能的变化情况。研究发现,随着道间温度的不断升高,微观组织中针状铁素体含量先增加后减少;熔敷金属中合金元素含量降低;力学性能中,抗拉强度和屈服强度逐渐降低,室温及-20℃低温冲击值先升高后降低;当道间温度达到160~175℃之间时,室温及-20℃低温冲击值最高,冲击平均值分别超过210 J和170 J;-20℃低温冲击断口形貌表明,试样冲击韧性越高,断口形貌中韧窝数量越多。
With R307 heat-resistant steel electrode as test material, the changes of microstructure and mechanical properties of deposited metal at different interpass temperatures were studied. The results show that the acicular ferrite content first increases and then decreases with the increase of the interpass temperature. The content of alloying elements in the deposited metal decreases. The tensile strength and yield strength decrease gradually in the mechanical properties. The room temperature And the impact value at -20 ℃ firstly increased and then decreased. When the interpass temperature reached 160 ~ 175 ℃, the impact values at room temperature and -20 ℃ were the highest, and the impact values exceeded 210 J and 170 J respectively. Impact fracture morphology shows that the higher the impact toughness of the specimen, the more the number of dimples in the fracture morphology.