关键词：钢铁；检测缺陷；Q370qE；桥梁建造钢板；微孔
摘 要：The flaws in a heavy bridge-making steel plate (Q370qE) were detected by ultrasonic test,the types and formation reasons of which were studied by metallographic examination,scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectrometer.The results showed that the types of the flaws were mainly crack,micropore and inclusion.The formation of crack and micropore was attributed to the center segregation,porosity,as well as the role of structural stress and thermal stress.Moreover,the inclusions were mainly composite oxides (MgO,Al2O3,CaO,etc.) and MnS,the former came from the raw materials and impurity oxides,however,the latter came from the center segregation of the alloying elements.Besides,some improvement measures to reduce detecting flaws were also proposed.