1Cr17Ni2不锈钢轴扩口破裂原因分析

1Cr17Ni2不锈钢轴在扩口时常出现批次性破裂。通过对多批次1Cr17Ni2不锈钢轴金相组织进行分析，结果表明:1Cr17Ni2不锈钢中存在严重的气孔和疏松是造成扩口批次性破裂的主要原因之一；高含量的δ-铁素体是造成扩口批次性破裂的又一主要原因；δ-铁素体含量越少，尺寸越细小，越不易出现扩口破裂。增加热处理次数会导致1Cr17Ni2不锈钢钢淬火后δ-铁素体含量增加。

Fracture Analysis of Expanded Mouth of 1Cr17Ni2 Stainless Steel Shafts

During the expansion of 1Cr17Ni2 stainless steel shaft, cracking frequently occurred at the expended mouth. Through metallurgical examination on several batches of 1Cr17Ni2 stainless steel shafts, the failure cause was analyzed. The results indicate that serious blowholes and pinholes are one of the main causes for the failure. The high content of δ-ferrite in the 1Cr17Ni2 steel is another main reason. The lower content and the smaller size of δ-ferrite the 1Cr17Ni2 steel has, the smaller the possibility for the cracking of the expanded mouth is. With the frequencies of heat treatment increasing, the content of δ-ferrite in the 1Cr17Ni2 steel after quenching would significantly increase.