利用OM和SEM研究了核反应堆驱动机构用12Cr13不锈钢的组织特征, 分析了退火态组织中碳化物形貌及其对冲击韧性的影响. 实验结果表明, 碳化物形貌是决定不锈钢冲击韧性的关键因素. 分布在原马氏体晶粒内、尺寸细小、分布均匀的颗粒状碳化物可显著改善12Cr13的冲击性能; 而分布在晶界上的块状和条状碳化物, 以及铁素体晶粒内随机分布的大颗粒状碳化物, 则严重恶化不锈钢的冲击韧性. 退火温度对碳化物析出和分布具有较大影响, 当退火处理温度由760 ℃升高到860 ℃时, 碳化物尺寸增大, 使得12Cr13不锈钢的冲击功由151 J降低到106 J; 当碳化物完全消失且呈块状或条状分布时, 不锈钢冲击功降低至5 J.
The microstructure and its effect on impact toughness of the annealed 12Cr13 stainless steel were investigated by OM and SEM. The results show that the morphology of carbides is the main factor that influences the impact properties. Globular-like, block or strip-like carbides precipitated continuously during annealing. Fine globular-like carbides in the pre-existed martensite grains improved the impact toughness. Block or strip-like carbides at the grain boundaries or in the $\delta$--ferrite grains are detrimental to the impact property. The annealing temperature has significant effect on the carbide precipitation behavior. With the annealing temperature increasing from 760 ℃ to 860 ℃, carbides coarsen resulting in the decrease of the impact energy from 151 J to 106 J. The sample with only block or strip-like carbides has low impact energy of 5 J.
[1] Cardoso P H S, Kwietniewski C, Porto J P, Reguly A, Strohaecker T R. Mater Sci Eng, 2003; A351: 1
[2] Li H S. Special Steel Technol, 2006; 12(49): 25
(李海生. 特钢技术, 2006; 12(49): 25)
[3] Nikitin P N, Muraveva E M, Rudnev N F, Elyutina G I. Met Sci Heat Treat, 1979; 20: 573
[4] Mulford R A, Mcmahon C J, Pope D P, Feng H C. Metall Mater Trans, 1976; 7A: 1183
[5] Wen D C. Mater Trans, 2006; 47: 2779
[6] Bhadeshia H K D H, Honeycombe R W K. Steel–Microstructure and Properties. 3rd Ed., London: Linacre House, 2006: 247
[7] Wang X F, Qiao X L. Special Steel, 1991; 12(6): 34
(王晓芳, 乔雪莲. 特殊钢, 1991; 12(6): 34)
[8] Fujita Teruo. Translated by Ding W H, Zhang X J, Chen Y Z. Heat Treatment of Stainless Steels. Beijing: China Machine Press, 1983: 30
(藤田辉夫著; 丁文华, 张绪江, 陈玉璋译. 不锈钢的热处理. 北京: 机械工业出版社, 1983: 30)
[9] Miao B H, Northwood D O. Mater Sci Eng, 1993; A171: 21
[10] Li L C, Lai M O, Ma J. Mater Sci Eng, 1993; A171: 13
[11] Bain E C. Functions of the Alloying Elements in Steel. Ohio: American Society for Metals, 1945: 265
[12] Briant C L, Banerji S K. Int Met Rev, 1978; 23: 164
[13] Beachem C D. Metall Trans, 1975; 2: 377
[14] Zhang W H. Stainless Steels and Heat Treatment. Shenyang: Liaoning Science and Technology Publishing House, 2010: 119
(张文华. 不锈钢及其热处理. 沈阳: 辽宁科学技术出版社, 2010: 119)
[15] Tsai M C, Chiou C S, Du J S, Yang J R. Mater Sci Eng, 2002; A332: 1
[16] Cui Z Q, Tan Y C. Metallography and Heat Treatment. 2nd Ed., Beijing: China Machine Press, 2007: 268
(崔忠圻, 覃耀春. 金属学与热处理. 第二版, 北京: 机械工业出版社, 2007: 268)
[17] Li J H, Lin D C. Metallographical Atlas for Metallic Materials. Beijing: China Machine Press, 2007: 969
(李炯辉, 林德成. 金属材料金相图谱. 北京: 机械工业出版社, 2007: 969)
[18] Mao W M, Zhu J C, Li J, Long Y, Fan Q C. The Structure and Properties of Metallic Materials. Beijing: Tsinghua University Press, 2008: 200
(毛卫民, 朱景川, 郦剑, 龙 毅, 范群成. 金属材料结构与性能. 北京: 清华大学出版社, 2008: 200)
[19] Huang Q Y, Li H K. Superalloy. Beijing: Metallurgical Industry Press, 2000: 28
(黄乾尧, 李汉康. 高温合金. 北京: 冶金工业出版社, 2000: 28)
