某镍基粉末高温合金盘坯的热处理开裂分析

Analysis of heat treatment cracking of one Ni-based powder metallurgy superalloy disk

针对某镍基粉末高温合金盘坯在热处理后开裂的问题进行了分析。结果表明:盘坯组织中存在热诱导孔隙缺陷,热诱导孔隙缺陷在盘坯表面形成了微裂纹,降低了材料的抗拉强度。盘坯在热处理过程中,受到残余应力共同作用,其数值超过了材料的抗拉强度导致开裂。该盘坯中的孔隙是由于包套在热等静压过程中漏气造成的,提高包套质量是消除盘坯热诱导孔隙缺陷的关键。

One cracking Ni-based powder metallurgy superalloy disk after heat treatment was analyzed. The results show that there is TIP（thermal induced pore） in the disc,and the surface micro-crack induced by TIP reduces the tensile strength of the disk. The residual stress resulted from heat treatment is beyond to the alloy strength,which means the disk cracking and failure. The formation of the pore is because of leaking of cans in the hot isostatic pressing. Improving the quality of cans is the key measure to eliminating the defect of TIP.