Answer: Corrosion is a common defect that affects the safety of pressure vessels. The degree of impact depends on the following aspects:
(1) The nature of corrosion. There are many types of corrosion, including uniform corrosion and non-uniform and dispersed corrosion. The most dangerous is the latter type of corrosion, such as stress corrosion, intergranular corrosion, hydrogen corrosion, wear, fatigue corrosion, thermal corrosion, pitting, sediment corrosion, waterline corrosion, alkali embrittlement, hydrogen embrittlement, etc. Clarifying the nature of corrosion is conducive to judging its degree of harm. The method of clarifying the nature mainly relies on inspection and analysis.
(2) The degree of corrosion. The depth, diameter, length and distribution of corrosion are the main indicators for judging the degree of corrosion. Measuring these parameters is necessary to judge the nature and degree of corrosion.
(3) Find out the cause of corrosion, firstly to identify the nature of corrosion, and secondly to take targeted measures to prevent corrosion from continuing to develop.
Mechanical damage, like corrosion, is a surface defect, but the type and cause are simpler than corrosion. It is usually left over from manufacturing, and sometimes caused by poor management during use. However, for pressure vessels with special requirements, when the mechanical damage is serious, the depth, length and distribution should also be measured, and corresponding measures and countermeasures should be taken according to the cause.
