深冷处理对Cr7V钢高温耐磨性与位错密度的影响

对Cr7V模具钢进行了(1030℃×0. 5 h)淬火+(-196℃×3,6,12 h)深冷处理+(560℃×2 h)三次回火处理,通过销盘摩擦磨损试验研究了深冷处理工艺参数对其高温耐磨性的影响。通过XRD获得不同热处理工艺下的衍射图谱,并通过X射线线形分析法研究深冷处理不同工艺参数对Cr7V模具钢位错密度的影响。结果表明:深冷处理对Cr7V模具钢高温耐磨性和位错密度的影响规律一致,随保温时间的延长,高温耐磨性和位错密度的提升程度均呈现先升后降的趋势,其中深冷保温6 h后试样磨损量为87. 6 mg,位错密度为1. 4295×10¹⁶m^-2,表现出最好的性能,其高温耐磨性较未深冷处理试样提高了53%,位错密度提高约28%。

Effect of cryogenic treatment on wear resistance at elevated temperature and dislocation density of tool steel Cr7V

The tool steel Cr7V was treated by quenching at 1030 ℃ for 0. 5 h,followed by deep cryogenic treatment at -196 ℃ for 3,6 and12 h and tempering at 560 ℃ for 2 h by three times. The effect of deep cryogenic treatment parameters on wear resistance of the Cr7V steel was studied by pin-on-disc friction and wear tests. The spectrums of the specimens with different heat treatment parameters were measured by means of XRD. The ray diffraction method was applied to evaluate the dislocation density of the specimens. The results show that the cryogenic treatment has the similar effect on the wear resistance and the dislocation density of the Cr7V steel,with the increase of the holding time,the wear resistance and the dislocation density has a tendency of increasing first and then decreasing. The specimen of cryogenic treated for 6 h and tempering by three times has mass loss of 87. 6 mg and dislocation density of 1. 4295 × 10^16 m^-2,the specimen shows the best properties,of which the wear resistance is improved by 53% and the dislocation density is increased by 28% compared with the specimen of conventional treatment.