本文对20CrMnMo进行了不同原始组织处理,分别对试样进行亚温淬火处理,再研究其微观组织和机械性能。研究结果表明：20CrMnMo钢经过预淬火+770℃亚温淬火+200℃低温回火后的组织(板条马氏体+条状铁素体)形态和分布较为均匀,并且具有良好的强度和塑性配合,其抗拉强度为σb=1

体，其强度和塑性配合最好。

(4)预淬火+亚温淬火+低温回火可获得的硬度与正火态＋亚温淬火+低温回火得的硬度基本相同，但强度与塑性却差的很多，可见亚温淬火后的强度不仅取决于强化相马氏体的含量，而且取决于韧性相铁素体的形态和分布。

参考文献

[1] 符蓉,王国顺.20SiMnTi钢亚温淬火工艺研究[J].热加工工艺,2002,(7):16.

[2] 周子年,马跃新,王小俊.亚温淬火及其强韧化机理的探讨[J].金属热处理,1984,(4):59.

[3] 董玉顺．马氏体加铁素体纤维状双相组织形成机理[J]．金属热处理学报，1990,(2)：54－62.

[4] 肖纪美.金属的韧性与韧化[M]．上海:上海科学技术出版杜，1980：415－430.

The Effect of Original Structure on Mechanical Properties of 20SiMnTi Steel of the Sub-critically Quenched Specimens

Zhang Shiying，Chi Changzhi

Department of Material Science and Engineering，Liaoning Technical University，FuXin，Liaoning

(123000)

Abstract In this paper, microstructure and mechanical properties of 20CrMnMo steel ,whose different original

structure undergoes sub-critical quench, have been investigated．The results show that ,after pre-quenching and 770℃sub-critical quench followed by 200℃ low temperature tempering, the structure is martensite and ferrite, configuration and distribution are uniform, the strength and plasticity of the steel match very well. The tensile strength is 1026.23MPa，the elongation is15.40% and the reduction of area is 54.95%.

Keywords：dual phase steel，room temperature deformation，aging treatment，sub-critical quenching