屈服强度1400MPa级超高强钢的研发及应用

Development of yield strength 1400 MPa grade ultra-high strength steel and its application

随着装备制造不断向着大型化、高端化和轻量化方向发展,对所使用结构钢板的强度、强韧性等提出了更高的要求。通过低碳当量和微合金化的成分设计,利用控制轧制和热处理相结合的方法,并协同细晶强化和纳米析出强化等方式,获得了强韧性匹配良好的屈服强度1 400 MPa级别超高强结构钢板,分析了不同热处理工艺对试制钢板组织和力学性能的影响规律,并在国内某钢企进行工业化试生产。结果表明:试制钢板在920℃淬火、180℃回火后,获得超细晶的回火板条马氏体组织,此时的强韧性配比最佳,屈服强度大于1 400 MPa,抗拉强度大于1 600 MPa,伸长率大于11%,-40℃冲击功大于40 J,产品综合性能良好。

With the development of equipment manufacturing towards large-scale, high-end and lightweight, the high requirements for the strength and toughness of structural steel plate are put forward. Through the composition design of low carbon equivalent and microalloying, the combination of controlled rolling and heat treatment, and the combination of fine grain strengthening and nano-precipitation strengthening, the yield strength of 1 400 MPa grade ultra-high strength structural steel plate with good strength and toughness was obtained. The influence rule of different heat treatment processes on the microstructure and mechanical properties of the tested plate was analyzed, and the industrial trial production was carried out in a domestic steel enterprise. The results show that ultrafine grain tempered lath martensite structure of tested steel is obtained after quenching at 920 ℃ and tempering at 180 ℃. At this time, the strength and toughness match is the best, the yield strength is greater than 1 400 MPa, the tensile strength is greater than 1 600 MPa, the elongation is greater than 11%, and the impact energy at-40 ℃ is greater than 40 J, the product has good composite performance.