GCr15SiMn轴承钢中碳元素偏析与疏松的相关性

针对GCr15SiMn钢锭在凝固过程中容易出现宏观偏析与疏松等凝固缺陷的问题，为了制定更合理的模铸浇注工艺，通过真空感应炉冶炼1 kg的GCr15SiMn钢锭，从模铸工艺和钢锭宏观组织的角度研究了实验室与工业生产的相似性，采用OPA、SEM等检验方法研究了碳偏析与疏松的相关性。研究表明，碳元素的偏析最为严重，碳元素偏析与疏松相关。得出了碳偏析与疏松的相关性公式SC=0.92P－0.89，该公式所体现出的基本规律适用于工业生产的铸锭。根据SEM和OPA的统计结果，建立了疏松的当量直径与其定量表征值(表观致密度P)的对应关系。结果表明，随着疏松的当量直径增大，碳的偏析度逐渐增大。利用Scheil微观偏析模型从原理上进行了分析与讨论，得出碳的偏析度和钢液收缩量呈正相关关系。

Correlation between carbon segregation and #br#porosity in GCr15SiMn bearing steel

Some solidification defects such as macrosegregation and porosity will occur during the solidification of GCr15SiMn steel ingots. In order to develop a more reasonable die casting process, the GCr15SiMn ingot of 1 kg was smelted in vacuum induction furnace. And the similarity between laboratory and industrial production was studied from the perspective of the die casting process and the macrostructure of ingot. The correlation between the carbon segregation and porosity of GCr15SiMn ingot was studied by OPA and SEM. The results showed that the segregation of carbon was the most serious and related to porosity. The relationship between segregation degree (S) of carbon and compactness degree (P) can be expressed as SC=0.92P－0.89. The basic law embodied in this formula was applicable to industrial ingots. According to the statistical results of SEM and OPA, the corresponding relationship between the equivalent diameter of the porosity and the quantitative characterization value (compactness degree P) was established. The result showed that the segregation degree of carbon increased with the increase of the equivalent diameter of porosity. The Scheil model was used to analyze and discuss in principle, and it was found that the segregation degree of carbon was positively correlated with the shrinkage of molten steel.