轧制工艺对14Cr1MoR钢板组织与性能的影响

采取光学显微镜、扫描电镜及拉伸、冲击试验机对板厚60 mm的14Cr1MoR热轧钢板正火+回火态和模拟焊后态的组织与性能进行了研究。结果表明:一阶段控轧与两阶段控轧的钢板相比,终轧温度高,轧后冷却速度慢,钢板铁素体晶粒尺寸粗大,珠光体含量多;钢板的强度低,伸长率高,冲击性能低。两阶段控轧的钢板经655 ℃保温3 h模拟焊后热处理,屈服强度下降44 MPa,抗拉强度下降24 MPa,冲击吸能能量降低;模拟焊后保温时间延长到12 h,强度和冲击性能变化不大。两阶段控轧的14CrMoR钢板,经正火+回火或再经过655 ℃模拟焊后热处理,钢板的力学性能优良。

Effect of rolling process on microstructure and properties of 14Cr1MoR steel plate

Microstructure and properties of 14Cr1MoR hot rolled steel plate with 60 mm thickness after normalizing+tempering, and simulated post-weld heat treatment were studied by using optical microscope, scanning electron microscope, tensile and impact testing machine. The results show that compared the steel plate of one-stage controlled rolling with that of two-stage controlled rolling, when the final rolling temperature is high and the cooling rate after rolling is slow, the ferrite grain size is coarser and the pearlite content is higher; the steel plate has lower strength, higher elongation, and lower impact value. After simulated post-weld heat treatment at 655 ℃ for 3 h, the yield strength and tensile strength of the two-stage controlled rolling steel plate decrease by 44 MPa and 24 MPa, respectively, and the impact absorbed energy decreases. When the simulated holding time is extended to 12 h, the strength and impact properties do not change much. The two-stage controlled rolling 14CrMoR steel plate has good mechanical properties after normalizing+tempering+simulated post-weld heat treatment at 655 ℃.