GCr15轴承钢大方坯宏观碳偏析的分析

Analysis on Carbon Macro-segregation in Large Square Billets of GCr15 Bearing Steel

对断面280 mm×325 mm的GCr15轴承钢进行了热酸浸实验与碳偏析检测,研究了碳偏析的低倍组织形貌,探讨了V型偏析的形成机理。结果表明,偏析在铸坯纵剖面上呈V型分布,且V型偏析仅分布于等轴晶区,凝固组织与偏析的形成有密切关系;同时碳元素在铸坯皮下呈负偏析,混晶区呈正偏析。

The hot acid leaching test and carbon segregation test of GCr15 bearing steel with cross section of 280 mm ×325 mm were carried out. The morphologies of low power microstructure of carbon segregation were studied. The formation mechanism of V-type segregation was discussed. The results show that the segregation is a V-type distribution in the longitudinal section of the casting blank, and the V-type segregation is only distributed in the equiaxed crystal region, and the solidification microstructure is closely related to the formation of the segregation. At the same time, the carbon element under the skin of the billet shows negative segregation and positive segregation in the mixed crystal zone.