Abstract: The microhardness, impact toughness, wear resistance, phases composition and microstructure of die steel for auto engine crankshaft forging of boroning process at 850 ~950 ℃ 3 ~6 h are studied. The research results show that the steel boronized at 925 ℃ for 4 h has better performance, that is the maximum HV microhardness value of tlie boronizing lay¬er 1712,the thickness of the boronizing layer 58.6 pjn,and the impact toughness value at 400 ℃ and 24 ℃ respectively 39 J • cm^-2 and 27 J • cm^-2 ,and the wear amount after 90 min friction test 6.7 mg of die steel. The phase composition shows that the main phase of the boronizing layer is Fe₂B, while the boriding layer,transition layer and matrix microstructure are obviously observed in microstructure.

Key words: Boronizing Process, Die Steel for Automobile, Properties, Microstructure ,

摘要： 研究了850～950℃3～6 h渗硼处理的汽车发动机曲轴锻造用模具钢的显微硬度、冲击韧性、耐磨性能以及物相组成和微观结构。研究结果表明,925℃渗硼4 h后的样品性能较优,模具钢渗硼层最大HV显微硬度值1712,渗层厚度58.6μm,400℃和24℃冲击韧性值分别为39 J·cm^-2和27 J·cm^-2,90 min摩擦试验后的磨损量6.7 mg。物相组成显示渗硼层主相为Fe₂B,显微结构中可以明显看见渗硼后的渗硼层、过渡层以及基体。

关键词: 渗硼工艺, 汽车模具钢, 性能, 微观结构