Effect of Heat Treatment on Microstructure and Hardness of 9Cr13Mo3Co3Nb2V Steel

• Main Authors: HUO Dengping, LIANG Zhikai
• Format: Article
• Language: zho
• Published: Journal of Aeronautical Materials 2016-12-01
• Series: Journal of Aeronautical Materials
• Subjects: 9Cr13Mo3Co3Nb2V steel; secondary hardening; heat treatment; microstructure; hardness
• Online Access: http://jam.biam.ac.cn/CN/10.11868/j.issn.1005-5053.2016.6.006

Effect of heat treatment on the microstructure and hardness of 9Cr13Mo3Co3Nb2V steel was studied systematically by metallographic examination and hardness testing. The results show that after quenching, cryogenic treatment and multiple tempering, the retained austenite of 9Cr13Mo3Co3Nb2V steel is adequately transformed into tempered martensite, and the significant secondary hardening effect is brought. Consequently the steel gains stable microstructure and high hardness. Secondary carbide begins to precipitate and the secondary hardening effect emerges when the tempering temperature is above 350℃, and the tempering hardness reaches the maximum value when tempering temperature range is from 480℃ to 520℃.