建筑用C345-3耐低温热轧H型钢应变时效敏感性行为研究  

Study on strain aging sensitivity behavior of C345-3low-temperature resistant hot rolled H-beam for construction

作　　者：冯岩青 黄飞 吴国臣 王海燕[3] 田方铖 吴娟 FENG Yanqing;HUANG Fei;WU Guochen;WANG Hanyan;TIAN Fangcheng;WU Juan(Baotou Vocational and Technical College,Baotou 014030,China;Wuhai Baosteel Wanteng Iron and Steel Co.,Ltd.,Wuhai 016000,China;Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]包头职业技术学院,内蒙古包头014030 [2]乌海市包钢万腾钢铁有限责任公司,内蒙古乌海016000 [3]内蒙古科技大学,内蒙古包头014010

出　　处：《轧钢》2025年第1期101-106,共6页Steel Rolling

基　　金：国家自然科学基金项目(52161008);中央引导地方科技发展资金项目(2022ZY0072);包头职业技术学院新材料工艺改进及性能控制创新团队项目(CX202203)。

摘　　要：热轧H型钢作为主体承重构件结构钢,其低温应变时效敏感性问题被越来越多的学者所关注。利用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、应变时效敏感度实验和夏比冲击试验对C345-3热轧H型钢组织特征、低温冲击断口、应变时效敏感性进行了研究。结果表明:实验钢经5%应变时效处理后,时效脆性倾向随测试温度的降低而增加,当实验钢处于韧脆转变温度以下时,时效脆性表现显著。实验钢应变时效后,其微观组织中出现了少量弥散分布的析出相渗碳体(Fe_(3)C)颗粒;低温冲击断口面上存在二次裂纹,恶化了实验钢的低温韧性。同时,钢中的位错密度增加,会引起能量升高和内部应力的出现,而Cottrell气团越多,位错运动受到阻碍、钉扎作用力越大,实验钢在应变时效时后的强韧性降低。实验钢-40℃时V型缺口试样的应变时效敏感系数C_(V)仅为14%,-70℃时U型缺口试样的应变时效敏感系数C_(V)仅为20%。As the main load bearing member structural steel,hot rolled H-beam has attracted more and more scholars'attention to the sensitivity of its strain aging at low temperature.Optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),strain aging sensitivity test and Charpy impact test were used to study the microstructure characteristics,low-temperature impact fracture and strain aging sensitivity of C345-3hot rolled H-beam.The results show that the brittleness tendency of the experimental steel increases with the decrease of the test temperature after 5%strain aging treatment,and the aging brittleness performance is significant when the experimental steel is below the tough-brittle transition temperature.In the microstructure,a small amount of dispersed precipitated carbide(Fe_(3)C)particles can be observed after strain aging,and there are secondary cracks on the low-temperature impact fracture surface of the experimental steel,which worsens the low-temperature toughness of the steel.At the same time,the increase of dislocation density in the steel will cause the increase of energy and the occurrence of internal stress,while the more Cottrell air masses,the more the dislocation movement will be hindered,the greater the pinning force,and the strength and toughness of the experimental steel after strain aging will decrease.The strain aging sensitivity coefficient C_(V)of the V-shaped notched specimen was only 14%at-40℃,and the strain aging sensitivity coefficient C_(V)of the U-notched specimen was only 20%at-70℃.

关 键 词：热轧H型钢 低合金钢 应变时效敏感性 冲击韧性 

分 类 号：TG335.11[金属学及工艺—金属压力加工] TU511.3[建筑科学—建筑技术科学]