摘要
采用洛氏硬度计、光学显微镜、扫描电镜、透射电镜等研究了回火冷却方式对80 mm厚Q690D钢硬度、微观组织、-20℃低温冲击性能的影响。结果表明,回火冷却方式对试验钢调质态厚度方向上的硬度分布基本没有影响,和淬火态硬度相比,最大硬度差由13 HRC降低至6 HRC。620℃回火后空冷,碳化物沿奥氏体晶界、板条界析出,试验钢-20℃冲击吸收能量为65 J,冲击断口形貌为准解理特征。回火后采用5~8℃/s的水冷,碳化物在晶界、板条界的析出受到抑制,试验钢-20℃冲击吸收能量提高到210 J,断口形貌以韧窝为主。采用回火后水冷,工业化生产的试验钢-20℃低温冲击吸收能量为174~252 J,和空冷工艺相比,冲击性能提高了105%~397%。
Rockwell hardness tester,optical microscope,scanning electron microscope and transmission electron microscope were used to study the effects of tempering cooling method on the hardness,microstructure and-20℃low-temperature impact toughness of 80 mm thick Q690D steel.The results show that the tempering cooling method has little effect on the hardness distribution in the thickness direction of the quenched and tempered steel,compared with the quenched state hardness,the maximum hardness difference decreases from 13 HRC to 6 HRC.After tempering at 620℃followed by air cooling,carbides precipitate along austenite grain boundary and lath boundary,the impact absorbed energy of the steel at-20℃is 65 J,and the impact fracture morphology is quasi cleavage.After tempering followed by water cooling(5-8℃/s),the precipitation of carbide at grain boundary and strip boundary is restrained,the impact absorbed energy of the steel at-20℃is increased to 210 J,and the fracture morphology is mainly dimples.After tempering followed by water cooling,the impact absorbed energy at-20℃of industrial produced steel is 174-252 J,which is increased by 105%to 397%compared with air cooling.
作者
杨维宇
刘颖
刘泽田
姜秉坤
Yang Weiyu;Liu Ying;Liu Zetian;Jiang Bingkun(Technical Center,Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou Inner Mongolia 014010,China;School of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot Inner Mongolia O10051,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2024年第12期46-51,共6页
Heat Treatment of Metals
基金
中央引导地方科技发展资金项目(2024ZY0099)
内蒙古自治区自然科学基金(2022QN05005)
内蒙古自治区直属高校基本科研业务费项目(JY20220109)
内蒙古工业大学科学研究项目(ZZ202104)。
关键词
Q690D钢
厚规格
回火冷却方式
碳化物析出
力学性能
Q690D
thickness specification
tempering cooling method
carbide precipitation
mechanical properties
