低温环境中Q345qD对接焊缝力学性能与冲击韧性  

MECHANICAL BEHAVIOR AND IMPACT TOUGHNESS OF Q345QD BUTT WELD AT LOW TEMPERATURE

作　　者：贾单锋 王元清[3] 崔佳[2] 廖小伟[3] 石永久[3] JIA Danfeng;WANG Yuanqing;CUI Jia;LIAO Xiaowei;SHI Yongjiu(Shenzhen China Merchants Real Estate Co. , Ltd. , Guangdong Shenzhen 518067, China;School of Civil Engi. , Chongqing Univ. , Chongqing 400045, China;Key laboratory of Civil Engin. Safety and Durability of China Education Ministry, Department of Civil Engi. , Tsinghua Univ. Beijing 100084, China)

机构地区：[1]深圳招商房地产有限公司,广东深圳518067 [2]重庆大学土木工程学院,重庆400045 [3]清华大学土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《低温建筑技术》2017年第12期23-26,共4页Low Temperature Architecture Technology

基　　金：国家自然科学基金(51378289);国家自然科学基金(51678339);高等学校博士学科点专项科研基金(20130002110085)

摘　　要：焊接钢桥在低温环境的断裂评估对焊接节点的力学性能及冲击韧性随温度变化规律研究提出了迫切的需求。本文对Q345qD对接焊缝进行了硬度测试、低温拉伸试验和低温冲击试验,得到焊接接头的硬度分布规律和5个温度点下强度、塑性、断裂及冲击韧性等参数,提出屈服应力、极限应力和冲击功随温度变化的关系曲线。结果表明,随环境温度的降低,Q345qD对接焊缝的屈服应力和极限应力有所增加,屈强比减小,冲击韧性下降,塑性指标和断裂应力没有明显变化。与高强度钢材对接焊缝相比,Q345qD对接焊缝冲击功中弹性功占比较小,对温度的敏感性更高。The fracture evaluation of welded steel bridge in low forward the urgent demand for the study of the mechanical behavior and at different temperature. The experiments of hardness, low-temperature pact were executed in this paper. The hardness distribution, strength temperature environment has put impact toughness of welded joints tension and low-temperature im- , plasticity, fracture and impact toughness of the butt weld were obtained at 5 temperature points, and the relationship curves of yield stress, ultimate stress and impact energy with temperature were also presented. The results show that the yield stress and ultimate stress of the Q345qD butt welds increase as the ambient temperature decreasing, while the yield strength ratio and impact toughness decrease, and the plasticity index and fracture stress do not change obviously. In addition, compared with the high strength steel butt weld, Q345qD butt weld is more sensitive with temperature decreasing because the elastic work takes minor proportion of the impact energy.

关 键 词：低温 对接焊缝 力学性能 冲击韧性 防断设计 

分 类 号：TU391[建筑科学—结构工程]