摘要
改编了碳偏析指数随温度及时间的变化模型,研究了一种线材碳偏析指数在热扩散试验中的变化规律,通过试验验证了碳偏析模型的有效性,并根据模型公式预测了铸坯碳偏析指数需要的热扩散时间。试验结果表明:线材在1200℃经2 min和4 min热扩散后,其碳偏析可以降低至1. 10和1. 05以下,空冷组织网状渗碳体级别显著降低。线材热扩散试验数据与模拟数值趋势一致,存在着线材升温至稳定所需的约0. 5 min差值。经过数值模拟,铸坯经过1200℃-590 min热扩散后偏析指数可降低至要求范围,但在实际操作中需考虑铸坯在加热过程中的热扩散。
The variation of carbon segregation index with temperature and time was adapted in this paper,and the variation of carbon segregation index of wire rod in thermal diffusion test was obtained. The validity of the carbon segregation model was verified by experiments.The thermal diffusion time of carbon segregation index in the slab was predicted according to the model formula. The results show that the carbon segregation of high carbon steel wire can be reduced to less than 1. 10 and 1. 05 after 2 min and 4 min heat diffusion at 1200 ℃,the cementite net level of the air cooled microstructure is significantly reduced. The wire thermal diffusivity test data and numerical simulation trend are consistent. There is a 0. 5 min difference between wire rod heating and stability. The segregation index of the billet can be reduced to the required range after 590 min heat diffusion at 1200 ℃ through numerical simulation,but the heat diffusion of the billet during the heating process should be considered in the actual operation.
引文
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