铸造低合金Cr-Mo钢CCT曲线的测试及分析
发布时间:2018-01-21 20:03
本文关键词: Cr-Mo钢 组织转变 CCT曲线 冷却速度 元素分布 出处:《铸造技术》2017年11期 论文类型:期刊论文
【摘要】:借助Gleeble-1500D热模拟试验机,根据温度传感器实时提取出来的温度-时间曲线计算冷却速度,采用分段冷却的方式,得到了铸造低合金Cr-Mo钢的连续冷却转变CCT曲线,并对其进行了分析。结果表明,铸造低合金Cr-Mo钢的Ac3,Ac1和Ms分别为925,765和485℃。冷却速度小于3℃/s时,发生奥氏体向贝氏体的转变;冷却速度为3~18℃/s时,发生奥氏体向珠光体和贝氏体的转变;冷却速度为18~50℃/s时,出现马氏体;冷却速度大于50℃/s时,只发生马氏体转变。CCT曲线中珠光体和贝氏体两大转变区相互分开,Ms线右端下降,没有先共析铁素体转变区。随着冷却速度的增加,硬度值逐渐增大;随着冷却速度的减小,元素分布趋于均匀,较慢的冷速有利于生成细小均匀的室温组织。
[Abstract]:With the help of Gleeble-1500D thermal simulation testing machine, the cooling rate is calculated according to the temperature-time curve extracted from the temperature sensor in real time, and the method of subsection cooling is adopted. The continuous cooling transition CCT curves of cast low alloy Cr-Mo steel are obtained and analyzed. The results show that the cast low alloy Cr-Mo steel has 925 Ac1 and Ms, respectively. When the cooling rate is less than 3 鈩,
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