热轧工艺对700MPa级带钢组织性能的影响

EFFECT OF CONTROLLED ROLLING PROCESSING ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF HOT ROLLED FORMABLE STRIP STEEL WITH YIELD STRENGTH OF 700 MPa

采用低C添加Si Mn Nb Ti成分,通过两阶段控制轧制开发出了屈服强度为700MPa级热轧带钢。研究了不同轧制温度对钢板力学性能及析出粒子的影响规律,并采用TEM、SEM等实验技术对钢板经不同时间时效处理后的组织及析出强化规律进行了研究。结果表明,高温轧制更有利于析出粒子在后续卷取保温过程中的析出,从而提高强度;降低终轧温度能获得良好的韧性。

A low carbon SiMnNbTi hot-rolled strip steel with yield strength of 700 MPa was developed by thermo-mechanieally controlled processing （TMCP）. The precipitation-hardening behavior and mechanical properties of test plates rolled at different temperatures were analyzed. The microstrueture and precipitates with different aging times at the same aging temperature were researched by using TEM and SEM analysis test and so on. The results showed that the higher rolling temperature was in favor of the precipitation of the carbonitrides during the coiling procedure. The lower rolling temperature was adopted in the industrial production in order to obtain excellent impact toughness.