控轧控冷工艺对30CrMnTi盘条组织和性能的影响

Influence of Controlled Rolling and Cooling Process on Microstructure and Mechanical Properties of 30CrMnTi Wire Rod

研究了控轧控冷工艺对φ6.5 mm规格30CrMnTi热轧盘条显微组织和性能的影响,并进行了相关分析。结果表明:降低吐丝温度和辊道速度能有效降低其抗拉强度、屈服强度和硬度,提高断面收缩率和断后伸长率,异常组织贝氏体含量的减少是各性能发生变化的根本原因。降低吐丝温度和辊道速度,使吐丝温度接近相变温度,降低盘卷出保温罩的温度,延长珠光体转变区域停留时间,有利于异常组织贝氏体含量的降低。为保证盘条显微组织是铁素体+珠光体,吐丝温度应控制在(790±10)℃,辊道速度应控制在0.19 m/s。

The effects of controlled rolling and cooling process on microstructure and mechanical properties of 30CrMnTi wire rod with 4,6.5 ram were studied. And the correlation analysis was carried out. The results show that reducing spinning temperature and roller speed can efficiently reduce the tensile strength, yield strength and hardness of the steel, and enhance the increase of reduction ratio of area and elongation. The decrease of content of abnormal bainite is the root cause of the changes of all performances. Reducing spinning temperature and roller speed, the spinning temperature closing to the phase transition temperature, and reducing the temperature of the coil out of the insulation cover,and extending pearlite transition region residence time are advantageous to the reduction of the bainite content of abnormal microstructure. In order to ensure that the microstructure of wire rod is ferrite＋pearlite, spinning temperature should be controlled at （790±10）℃, and roller speed should be controlled at 0.19 m/s.