ZG25MnCrNi钢组织偏析铸件的热处理工艺

为了使存在明显组织偏析的ZG25MnCrNi钢铸件的断后伸长率和断面收缩率达到技术要求，通过试验，分析研究了正火温度、回火温度对其强度和塑性的影响，以及显微组织发生的变化。结果表明，900～920℃保温120min正火，随后在600～640℃回火，铸件断后伸长率和断面收缩率均达到并超过了技术要求，获得了良好的综合力学性能，虽然组织偏析仍然存在，但偏析部分的组织应力得以消除，能够满足使用要求。

Heat Treatment for ZG25MnCrNi Steel Castings with Segregated Structure

In order to make the elongation and percentage reduction in area of ZG25MnCrNi steel castings with segregated structure satisfy the reqirements of standard, the effect of normalizing temperature and tempering temperature on strength, plasticity and microstructure of the castings was investigated. The results show that the castings austenitized at 900 -920 ℃ for 120 min and cooled in air and subsequently tempered at 600 -640 ℃ will possess both elongation and percentage reduction in area equal to or above the standard, and gain good mechanical properties. Although the segerated structure still exists in the castings, a transformation stress in segerated zone has been eliminated, with the castings meeting the needs of application.