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~试验研究~
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一种高强度低合金贝氏体钢高温回火析出的极细MC租
般匠1,4，刘天威2，刘文庆
（1.上海贝钢锁材工作室，上海200439;2.中国石油大学（北京）材料科学与工程系，北京102249； 3.上海大学分析测试中心，上海200444;4.江苏亚星锚链股份有限公司，江苏靖江214533）
摘要：将一种直径为100mm的高强度低合金贝氏体圆钢，于980℃奥氏体化1h水泽，切割成试片，然后
进行620℃×0.5h回火处理。采用透射电子显微镜（TEM)和三维原子探针分析技术（3DAP）详细研完了钢的淬火态组织和碳化物析出相。结果，钢的萍火态组织为上、下贝氏体和马氏体，回火后，主要析出相是三种合金碳化物：（1）-M,C型渗碳体，其大小为50nm以下，主要分布在板条铁素体晶界；（2）铁素体板条内析出的针形ε-M,C型碳化物，宽度小于20nm，长度小于200nm，分布较均匀；（3）铁素体板条内析出的约2nm大小的高密度MC型碳化物。此外，论述了三种析出相对材料性能可能的影响。
关键词：贝氏体钢；碳化物；微观结构：三维原子探针：透射电镜：R5级海洋系泊链
中图分类号：TG115.21
文献标识码：A
文章编号：1008-1690（2016)04-0009-09
Ultra-Fine MC-Type Precipitates Formed During High Tempering in a High-Strength Low-Alloy Bainitic Steel
YINJiang'.4，LIUTianwei2，LIUWenqing
(1.Shanghai Bainite Chain Material Workshop,Shanghai 200439,China;
2. Materials Science and Engineering Department of China University of Petroleum, Beijing 102249, China
3. Analysis and Test Center of Shanghai University, Shanghai 200444, China; 4. Jiangsu Asian Star Anchor Chain Co., Ltd., Jingjiang 214533, Jiangsu China)
Abstract: A bar steel 100 mm in diameter, made of high-strength low-alloy bainitic steel, was austenitized at 980 °C for 1 h and quenched in water, cut into test pieces, and then tempered at 620 °C for 30 min. As-quenched microstructure and various precipitated carbides in the steel were investigated in detail by using TEM and three dimensional atom probe (3DAP). The results indicate that as-quenched microstructure of the steel consists of upper beinite, lower beinite and martensite; and that there are three categories of alloy carbide were observed in the steel tempered : (1) 3-M, C cementite as size as less than 50 nm,essentially lies in lath ferrite boundaries; (2) acicular-M,C carbide, which precipitates in lath ferrite of the steel, is as size as less than 20 nm wide by less than 200 nm long, and exhibits uniform distribution; (3) highly dense MC carbide as size as about 2 nm. Beyond this, the possible effect of the three types of precipitates on mechanical properties of the steel was discussed.
Key words: bainitic steel; carbide; microstructure; three-dimensional atom probe (3DAP); TEM; R5 grade offshoremooringchain
收稿日期：2016-03-31
作者简介：般匠（1941-），男，江苏宜兴人，清华大学工学博士，教授级高工，享受国务院津贴，日本钢铁协会
(ISIJ)海外会员；曾在上钢五厂（宝钢特钢）从事特钢劳动、工程实践和自主科学研究50年,2012 年至今继续担任海工、特钢行业首席专家和学术委员，领衔国家级课题和钢的海洋环境氢脆研究。以融合特殊钢材料科学和工程的模式进行应用研究，设计原创性成分和工艺，包括部件裂纹机制研究和预防措施。近年来在强度1GPa以上的大型深海系泊长链及其附件用高强韧低屈强比低氢脆敏感性钢的研制和产业化等方面取得多项研究成果，是获得国家科技进步特等奖的R5级系泊链的核心技术；作为第一完成人，获上海市科技进步一等奖、国家科技进步三等奖、国防科工委等国家和省部级奖励十余项，以及国内外发明奖项等荣誉。联系电话：13917990050，E-mail：yinjiang@asac.cn
《热处理》
2016年第31卷第4期
.9.