30Mn水淬钢调质热处理工艺的研究

测定了30Mn钢的CCT曲线和淬透性。研究表明,当冷却速度大于60℃/s时,能得到50%以上的马氏体组织,淬透性能满足Φ245mm×13.84mm以下油井管的要求。在此基础上研究了不同的回火温度、回火保温时间、淬火温度和淬火保温时间对30Mn钢组织性能的影响规律,制订了实验室条件下的调质热处理工艺,并进行了试验研究。结果表明,经此调质工艺处理后,材料的力学性能达到了API5CT标准要求。作为水淬钢种,30Mn钢可用来生产N80Q钢级的油井管。

Study on Quenching-and-tempering Process of Water-quenched 30Mn Steel

The continuous cooling transformation or CCT characteristics and hardenability of the 30Mn steel are investigated. The results show that when cooling rate is higher than 60 ℃/s, in the metallurgical structure of the specimen martensitic structure accounts for over 50%, and the hardenability is up to the requirement as set for oil well pipes with sizes under Ф 245mm × 13.84 mm. Based on these data, further investigation is conducted, in-volving the law of the effect of different temper temperature & temper soaking time and the quench temperature & quench soaking time on the mechanical properties of the 30Mn steel. Accordingly, relevant lab quenching-and-tempering process is designed and performed experimentally, resulting in the conclusion that the mechanical prop-erties of the 30Mn steel as quenched and tempered has met relevant requirements as specified in API Spec 5CT, and thus the 30Mn steel as a kind of water-quenched steel is applicable to the production of N80Q oil well pipes.