82B盘条非平衡态冷却异常组织形成机理研究

Study on the formation mechanism of abnormal structure in non-equilibrium cooling of 82B wire rod

对斯太尔摩风冷线非平衡态冷却生产的18.9万吨82B盘条进行统计分析,得出网状渗碳体出现的概率大于条状马氏体出现的概率。通过对比不同规格82B盘条散冷温度曲线,得出不同位置冷却速率的差异对芯部异常组织的形成具有诱导作用。通过相变推导论证,得出提高共析相变前搭接点温度有利于抑制网状渗碳体形成,降低相变快结束时的冷却速率有利于抑制铬锰偏析导致的条状马氏体形成。本研究结果为82B盘条非平衡态冷却的质量稳定提供改进思路。

A statistical analysis has been conducted to the 189,000 tons of 82B wire rod produced by the non-equilibrium cooling of the Steyrmore air-cooled line,it is obtained that the probability of occurrence of network cementite is greater than that of strip martensite.By comparing the cooling temperature curves of 82B wire rods of different specifications,it is concluded that the difference in cooling rate at different positions can induce the formation of abnormal core tissues.Through the deduction of phase transformation,it is concluded that increasing the temperature of the overlap point before the eutectoid transformation is beneficial to inhibit the formation of network cementite,and reducing the cooling rate at the end of the phase transformation is beneficial to inhibit the strip martensite caused by the segregation of chromium and manganese form.The results of this study provide improvement ideas for the stable quality of 82B wire rod in non-equilibrium cooling.