实验室条件下超高强度X120钢管微观组织和性能研究

摘要

Experimental melting is carried out at the Bardin TsNIIchermet research complex for smelting steel of strength category X120 of two chemical composition versions: microalloyed with and without boron. Thermomechanical rolling is implemented in a laboratory rolling mill with different interrupted cooling temperatures in order to form ferrite-bainite, bainite, and martensite structures. Accelerated tempering technology is simulated with the aim of increasing ductility and toughness. Mechanical tests and metallographic analysis are performed. The results show that the mechanical performance for steel of strength category X120 microalloyed without boron, the best aging temperature is 300 ℃ and cooling speed is 30 ~35℃/s;The best microstructure should be granular bainite. The steel obtained exhibits mechanical properties corresponding to strength category X120 according to standard.%在实验室条件下对含B和不含B的两种X120管线钢进行了熔体试验，在实验室的热机械轧制机上以不同的冷却速度轧制试验坯以获得不同的组织形态，同时为增加钢的延展性和韧性还模拟了加速回火技术，对试样均进行了力学性能试验和金相分析。结果表明，不含B 元素X120钢所需的力学性能，最佳时效温度为300℃且冷却速度为30～35℃/s；最佳的组织结构应为粒状贝氏体结构，该试验用钢显示了标准规定X120钢所具有的力学性能。