冷却速率对大型铸钢件用CrMoV材料冲击性能的影响

The influence of cooling rate on the impact properties of CrMoV materials for large steel castings

通过控制大型铸钢件试块热处理过程保温温度和保温时间,对低合金耐热钢CrMoV材料进行(20~25)℃/min、(7~10)℃/min和(2~5)℃/min的冷却速率处理,研究其冲击性能和显微组织,得到最佳热处理冷却速率方案。结果表明:冷却速率由(20~25)℃/min降至(2~5)℃/min时,室温冲击均值由138J降至18.4J,显微组织由贝氏体组织变为贝氏体组织+少量铁素体组织。

By controlling the heat preservation temperature and time of the heat treatment process of large steel castings,the low alloy heat-resistant steel CrMoV material has been treated at(20~25)℃/min,(7~10)℃/min and(2~5)℃/min cooling rate.The impact performance and microstructure has been studied and the best heat treatment cooling rate plan has been obtained.The results show that when the cooling rate is reduced from(20~25)℃/min to(2~5)℃/min,the average room temperature impact is reduced from 138J to 18.4J,and the microstructure changes from bainite to bainite+a small amount of ferrite structure.