本标准适用于采用脉冲反射式超声波探伤仪对公称厚度大于等于50mm的压力容器用碳钢和低合金钢锻件进行的超声波探伤。并且规定了探伤方法和结果的等级分类。本标准不适用于奥氏体不锈钢等粗晶材料;也不适用于内径与外径之比在75%以下的环形和简形锻件的横波探伤。 This standard applies to the use of pulse reflectance ultrasonic flaw detector nominal thickness of 50mm or more for pressure vessels with carbon steel and low alloy steel forgings ultrasonic flaw detection. It also specifies the level classification of testing methods and results. This standard does not apply to austenitic stainless steel and other coarse-grained materials; also does not apply to the inner diameter and outer diameter ratio of less than 75% of the annular and simple forging transverse shear testing.