Answer: Deformation is one of the main defects that occur during the use of pressure vessels. There are many types of deformation. Bulging and bulging (including dents) are both deformations. The main reasons for formulating this article are:
(1) Different types of deformation have different impacts. Mechanical bulging caused by blunt impact and processing bulging caused by improper molds generally have no major impact; bulging and expansion caused by local overheating, local corrosion, local wear, and local scouring of metal are mostly caused by working conditions and threaten the safety of pressure vessels; hydrogen bulging caused by hydrogen is not only affected by working conditions, but also by material reasons. It is a dangerous defect. Analyzing the cause of deformation and determining the type of deformation will help determine whether the pressure vessel can continue to be used.
(2) Measuring the size of the deformation will help determine the severity of the deformation and provide data for analysis.
(3) Checking whether the bulge is accompanied by other defects is necessary to analyze the type of bulge and determine the degree of bulge damage. Mechanical bulges formed by impact of sharp objects should be subjected to surface nondestructive testing on the cold-worked hardened areas at the sharp corners; bulges caused by local corrosion may produce cracks, and severe hydrogen bulges may have cracks on the top.
