摘要:
以国内某厂65Mn矩形坯为研究对象,建立了矩形坯的传热和热弹塑性模型,模拟矩形坯凝固过程的温度场,以及在进行单点矫直时矫直点处的应力场分布情况;分析温度场及热应力的分布对铸坯质量的影响,为优化连铸工艺提高矩形坯的质量提供了理论依据。模拟结果表明:采用普碳钢工艺浇铸65Mn钢时,在矫直点还存在大量液芯,高拉速下铸坯处于带液芯矫直,较全凝固矫直而言,其应力云图出现了不规则分布,且应力梯度增大,大大增加了内裂的产生几率。通过对工艺优化前后的铸坯低倍进行对比分析发现,本研究所提出优化工艺方向合理,铸坯质量大幅提高,取得较好的实践效果。
Abstract:
The heat transfer and thermal plastic models had been established based on industrial 65 Mn rectangular billet,and been used to simulate solidification temperature field and stress field in straightening point,in order to determine the effect of the distribution of temperature field and thermal stress filed on casting slab quality. The simulation results indicate that when plain carbon steel casting process is used to cast 65 Mn steel,there is a large number of liquid core retained in the straightening point,high speed casting causes a irregular distribution of stress nephogram and the stress gradient increases,this will greatly increase the internal crack occurrence; Macro observation on billet indicates that the proposed process optimization can greatly improve the quality of casting billet.