摘要
To study the distribution law and random characteristics of casting defects in steel castings,24 civil engineering structural cast steel joints were divided into two groups:simple cast steel joints and complex cast steel joints.Three kinds of nondestructive testing(NDT)methods,namely,visual,magnetic particle,and ultrasonic inspections,were used to detect the macroscopic defects in joints.The NDT results were then statistically analyzed.The results show that the unfused core support is a common defect of complex cast steel joints,and the defect can be seen visually,so excavation and repair welding should be carried out before castings leave factories.Casting cracks are extremely likely to occur in the intersection area of tubes,which is called the ultrasonic inspection blind zone.The occurrence probability of gas pores on simple cast steel joints is the largest,and the occurrence probability of core support incomplete fusions on complex cast steel joints is the largest.However,when cast steel joints are counted as a whole sample,the occurrence probability of gas pores is larger than that of core support incomplete fusions.Therefore,it is the most common defect in cast steel joints.
为研究铸钢件中铸造缺陷的分布规律和随机特征,将24个土木工程结构用铸钢节点分为简单铸钢节点和复杂铸钢节点2组样本,利用目测、磁粉和超声波3种无损探伤方法对节点中的宏观铸造缺陷进行检测,然后对无损探伤试验结果进行统计分析.试验结果表明:芯撑未熔合缺陷为复杂铸钢节点中比较常见的缺陷,该类缺陷目视可见,在铸件出厂前都会进行挖除焊补;铸造裂纹极易出现在复杂铸钢节点的管管相交区域,而该区域为超声波探伤盲区;简单铸钢节点上气孔缺陷发生的概率最大,复杂铸钢节点上芯撑未融合缺陷发生的概率最大;将24个铸钢节点作为整体样本进行统计时,发现气孔缺陷发生的概率超过了未融合缺陷发生的概率,为铸钢节点中最常见的缺陷.
基金
The National Key R&D Program of China(No.2017YFC0805100)
the National Natural Science Foundation of China(No.51578137)
the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
the Open Research Fund Program of Jiangsu Key Laboratory of Engineering Mechanics。
