邓承元 丁灿灿 胡斌 罗海文. 初始组织对新型热成形钢显微组织和力学性能的影响[J]. 金属学报, DOI: 10.11900/0412.1961.2025.00081.

摘要 相关文章 Metrics 全文: PDF(2087 KB)   摘要: 利用热成形钢初始组织中碳化物在奥氏体化过程溶解产生的浓度梯度能够提高残余奥氏体含量，并利用残余奥氏体的相变诱导塑性(TRIP)效应改善塑性，但不同形貌初始组织对于热成形后组织和力学性能的影响缺乏研究。因此，本工作研究了不同形貌的珠光体初始组织对新型热成形钢Fe-0.29C-1.75Si-1.2Mn-2.1Cr-0.027Nb在915 ℃下短时热成形并烘烤后力学性能和微观组织的影响。结果表明，片状珠光体(LP)初始组织在915 ℃保温20~30 s的短时热成形后，其强度和塑性均优于球状珠光体(SP)初始组织。保温25 s时，LP初始组织样品的UTS、YS和TE比SP初始组织样品分别提高约75 MPa、35 MPa和1%，比22MnB5钢分别提高490 MPa、440 MPa和3%。针对奥氏体逆转变动力学的模拟计算结果表明，由于片状渗碳体的固溶速率高于球状渗碳体，在片状渗碳体上形核、长大的奥氏体的C含量也高于球状渗碳体形核的奥氏体，因此片状渗碳体区域的马氏体相变开始温度(Ms)更低。这一方面导致LP初始组织在热成形后的马氏体相变中产生更多位错，从而提高样品屈服强度，另一方面也增加了LP初始组织热成形后的残余奥氏体分数，进而可通过增强TRIP效应而改善加工硬化，所以其抗拉强度和延伸率也更优。 关键词 ： 热成形钢,  渗碳体,  初始组织,  力学性能,  残余奥氏体     Abstract：New press-hardening steels (PHSs) have been developed recently to further improve strength and ductility, meeting the demand of the automobile industries. PHSs are usually formed by retaining austenite grains with sufficient fraction and stability for enhancing the transformation-induced-plasticity (TRIP) effect by deliberately introducing spherical carbide particles, where austenite grains can be nucleated and grow in company with their gradual dissolution. However, lamellar pearlite (LP) microstructure, rather than spherical pearlite (SP), is commonly formed in automotive steels during industrial hot rolling. This study investigated the influence of the initial microstructure (LP or SP) on the resultant microstructures and tensile properties of a new PHS (Fe-0.29C-1.75Si-1.2Mn-2.1Cr-0.027Nb) after press-hardening with a short solution period at 915°C and baking at 170°C. The results show that compared to an initial SP structure, an initial LP structure resulted in higher yield strength (YS), ultimate tensile strength (UTS), and total elongation (TE) after the press-hardening at 915°C for 20-30 s. On increasing the solution period to 25 s, the YS, UTS, and TE of the LP specimen were higher than those of the SP specimen (by approximately 35 MPa, 75 MPa, and 1%, respectively) and the 22MnB5 specimen (by 440 MPa, 490 MPa, and 3%, respectively). The austenitic reversion kinetics in the solution were simulated using DICTRA. The simulation results indicate that lamellar cementite dissolves more rapidly than the spherical one under identical solution treatments. Moreover, the austenite that nucleated and grew on the lamellar cementite had a higher C content than the austenite on the spherical cementite. Thus, compared to an initial SP structure, an initial LP structure resulted in a lower start temperature of martensite transformation (Ms) under identical press-hardening processes. This resulted in a higher dislocation density in martensite in the LP specimen, improving its YS and retaining more austenite, thereby enhancing the TRIP effect after press-hardening and improving work hardening. Thus, compared to an initial SP structure, the LP one resulted in higher resultant YS, UTS, and TE after press-hardening with a solution period of 20-30 s. Key words： Press hardening steel,    cementite,    starting structure,    mechanical property,    retained austenite 收稿日期: 2025-03-31      基金资助:国家自然科学基金;云南省重点研发计划——材料基因组项目;中国宝武低碳冶金创新基金 服务 把本文推荐给朋友 加入引用管理器 E-mail Alert RSS 作者相关文章 邓承元 丁灿灿 胡斌 罗海文 44.8K 链接本文: https://www.ams.org.cn/CN/Y0/V/I/0 [1] 张天宇, 张鹏, 肖娜, 王小海, 刘国强, 杨志刚, 张弛. 奥氏体化温度对2 GPa超高强钢显微组织和力学性能的影响[J]. 金属学报, 2025, 61(9): 1353-1363. [2] 王洪瑛, 姚志浩, 李大禹, 郭婧, 姚凯俊, 董建新. 高 γ' 相含量粉末及变形高温合金组织和力学性能的异同性[J]. 金属学报, 2025, 61(9): 1364-1374. [3] 吴志勇, 邵徽凡, 蔡长春, 曾敏, 王振军, 王艳丽, 陈雷, 熊博文. 斜纹碳布缝合织物结构增强铝基复合材料的高温拉伸及断裂行为[J]. 金属学报, 2025, 61(9): 1387-1402. [4] 肖文龙, 臧晨阳, 郭锦涛, 冯佳文, 马朝利. 基于原位电阻法的7A65铝合金厚板双级时效工艺[J]. 金属学报, 2025, 61(8): 1153-1164. [5] 刘继浩, 迟宏宵, 武会宾, 马党参, 周健, 谷金波. 喷射成形工艺对M3高速钢碳化物特征及力学性能的影响[J]. 金属学报, 2025, 61(8): 1229-1244. [6] 谢昂, 陈胜虎, 姜海昌, 戎利建. Nb含量和均质化处理对奥氏体不锈钢铸态组织和力学性能的影响[J]. 金属学报, 2025, 61(7): 1035-1048. [7] 葛蓬华, 张勇, 李志明. 异构FeCoNi中熵合金的软磁与力学行为[J]. 金属学报, 2025, 61(7): 1119-1128. [8] 钦兰云, 张健, 伊俊振, 崔岩峰, 杨光, 王超. 固溶时效对激光沉积修复ZM6合金组织及力学性能的影响[J]. 金属学报, 2025, 61(6): 875-886. [9] 李夫顺, 刘志鹏, 丁灿灿, 胡斌, 罗海文. 一种新型高强奥氏体低密度钢的强塑性机理[J]. 金属学报, 2025, 61(6): 909-916. [10] 雷云龙, 杨康, 辛越, 姜自滔, 童宝宏, 张世宏. 机械合金化AlCrCu0.5Mo0.5Ni高熵合金及其后续退火态的结构演化[J]. 金属学报, 2025, 61(5): 731-743. [11] 孟祥龙, 刘瑞良, Li D. Y.. 钽合金表面渗碳层中碳化物析出及其性能的第一性原理研究[J]. 金属学报, 2025, 61(5): 797-808. [12] 孙军, 刘刚, 杨冲, 张鹏, 薛航. 耐热铝合金：组织设计与合金制备[J]. 金属学报, 2025, 61(4): 521-525. [13] 杨明辉, 李星吾, 孙崇昊, 阮莹. 定向凝固与固态相变双联协控下Monel K-500合金的组织和力学性能[J]. 金属学报, 2025, 61(4): 561-571. [14] 蔡正清, 尹大伟, 杨靓, 王文祥, 王飞龙, 温永清, 马明臻. Ag替换Cu对Zr-Ti-Cu-Al非晶合金性能的影响[J]. 金属学报, 2025, 61(4): 572-582. [15] 邹建新, 张嘉祺, 赵颖燕, 林羲, 丁文江. 高容量镁基储氢合金材料研究与应用进展[J]. 金属学报, 2025, 61(3): 420-436. Viewed Full text Abstract Cited   Shared      Discussed