深冷处理对17CrNiMo6钢渗碳层组织和硬度的影响
Effect of Cryogenic Treatment on Microstructure and Hardness in Carburized Layer of 17CrNiMo6 Steel

对经不同深冷工艺处理后的17CrNiMo6钢进行了组织观察、力学性能检测、摩擦磨损试验和X射线衍射试验。结果表明，回火前深冷处理能显著降低钢中残余奥氏体量，析出细小弥散的碳化物颗粒，且组织更加均匀，从而增大有效渗硬层深度，使钢的硬度和耐磨性得到显著提高，但冲击韧性略有降低。与普通热处理相比，回火后深冷处理出现大的块状碳化物，残余奥氏体含量增加，组织均匀性变差，对钢的性能改善不利。综合来讲，“淬火，840℃ × 2 h + 深冷处理，−150℃ × 10 h + 回火，200℃ × 4 h”工艺能使17CrNiMo6钢的组织和综合性能都达到最佳状态。

Abstract: The microstructure, mechanical properties, wear resistance and X-ray diffraction of 17CrNiMo6 steel with different cryogenic treatment were investigated. The results revealed that, when the samples experienced cryogenic treatment before tempering, the residual austenite content decreased significantly, more carbides precipitation formed in the steel and the microstructure was more uniform, thus the effective hardened layer depth increased. As a result, hardness and wear resistance improved obviously with a slight decrease of impact toughness. However, when the samples experienced cryogenic treatment after tempering, the lumpish carbides emerged, the content of retained austenite increased and the microstructure was less uniform than that of common heat treatment, which could not improve the performance of the steel well. In conclusion, the microstructure and combination properties of 17CrNiMo6 steel when it experienced cryogenic treatment at −150˚C for 10 h before tempering at 200˚C for 4 h achieved best.

[1] 李雄, 李士燕, 袁子洲. 深冷处理对高速钢高低温力学性能的影响研究[J]. 甘肃工业大学学报, 2001, 27(3): 80- 81.

[2] 陈鼎, 肖廷, 蒋琼, 陈劲松. 深冷处理对钢铁材料耐磨性的影响[J]. 矿冶工程, 2010, 30(2): 107-111.

[3] 闫献国, 庞思勤, 李永堂. 高速钢深冷处理技术研究进展[J]. 新技术新工艺, 2008(3): 14-18.

[4] 吕雁文, 闫献国, 韩晓君, 刘冈超, 智红英. 深冷处理对W6Mo5Cr4V2高速钢红硬性的影响[J]. 金属热处理, 2015, 40(10): 91-94.

[5] 陈鼎, 陈吉华, 严红革, 黄培云. 深冷处理原理及其在工业上的应用[J]. 兵器材料科学与工程, 2003, 26(3): 68- 72.

[6] 蔡红, 叶俭, 卢军. 《钢件深冷处理》标准探讨[J]. 金属热处理, 2011, 36(9): 67-69.

[7] 张劲松, 袁子洲, 刘秀芝, 李士燕. 金属材料深冷处理现状[J]. 甘肃工业大学学报, 2003, 29(1): 32-35.

[8] 刘勇, 于文平, 张金东, 田保红. 深冷处理对T8A钢组织和力学性能的影响[J]. 材料热处理学报, 2010, 31(10): 48-52．

[9] 阎红娟, 徐宏海. 深冷处理对W4Mo3Cr4VSi钻头耐磨性的影响[J]. 北方工业大学学报, 2009, 21(1): 63-66.

[10] 沈簧靓, 闵娜, 谢尘, 吴晓春. 深冷处理对80Cr9Mo2钢组织的影响研究[J]. 上海金属, 2014, 36(5): 13-18.

[11] Bensely, A., Venkatesh, S., Mohan Lal, D., et al. (2008) Effect of Cryogenic Treatment on Distribution of Residual Stress Incase Carburized En353 Steel. Materials Science and Engineering A, 479, 229-235.
https://doi.org/10.1016/j.msea.2007.07.035

[12] 张红, 王俊杰, 郭嘉. 深冷处理3Cr13对组织和力学性能的影响[J]. 热加工工艺, 2008, 37(22): 64 -66.

[13] 沙桂英. 高温奥氏体化对40Cr钢疲劳裂纹扩展行为的影响[J]. 金属热处理, 1990(11): 12-19.

[14] Liu, H.-H., Wang, J., Yang, H.-S., et al. (2006) Effect of Cryogenic Treatment on Property of 14Cr2Mn2V High Chromium Cast Iron Subjected to Subcritical Treatment. Journal of Iron and Steel Re-search International, 13, 43-48.
https://doi.org/10.1016/S1006-706X(06)60108-8