Nondestructive testing technology in the whole production process of stainless steel cap

　　1、 Radiographic examination

　　The radiographic inspection method is applicable to the inspection of internal defects of pressure vessel cap cover or butt weld. Generally, the thickness of steel suitable for inspection by X-ray flaw detector is not more than 80mm, the thickness range of lr-192 inspection is 20 ~ 100mm, and the thickness of Co-60 inspection is 40 ~ 200mm.

　　2、 Surface inspection

　　The magnetic particle or penetration method is generally used for the surface inspection of thick steel plate welds, fillet welds and butt welds during the production and manufacturing of pressure vessel cap, and also for the surface inspection of large and medium-sized steel castings after machining.

　　3、 Ultrasonic testing

　　The ultrasonic inspection method is applicable to the inspection of the internal defects of the butt weld of the pressure vessel cap shell with a thickness of more than 6mm