来源：http://www.tayfsk.com/ 发布时间：2023-08-24 浏览次数：
To ensure the long-term safe operation of heat-resistant steel welded joints under high temperature, high pressure, and various corrosive media conditions, the performance of pressure vessel automatic welding joints should meet the following requirements.
① The high-strength heat-resistant steel joint of the joint should not only have room temperature and high-temperature short-term strength that is basically equal to the base material, but more importantly, it should have high-temperature endurance strength similar to the base material.
② The hydrogen resistance and oxidation resistance of the joint. The heat-resistant steel joint should have basically the same hydrogen resistance and high-temperature oxidation resistance as the base material. Therefore, the alloy composition and content of the weld metal should be basically consistent with the base metal.
③ The structural stability of heat-resistant steel welded joints, especially thick walled joints, will undergo multiple heat treatments for a long time during the manufacturing process. During operation, they will be subjected to high temperature and pressure for a long time. There should be no obvious structural changes or resulting embrittlement or softening in each area of the joint.
④ Although most heat-resistant steel pressure vessels work at high temperatures, the resistance to brittle fracture of joints will undergo a water pressure test at 1.25 times the design pressure at room temperature after the completion of pressure vessel and pipeline manufacturing. After installation and maintenance, it is necessary to undergo a hydraulic test and a cold start process. Therefore, heat-resistant steel welded joints should also have a certain degree of resistance to brittle fracture.
⑤ The physical homogeneity of the joint is that the welded joint of heat-resistant steel should have basically the same physical properties as the base material. The thermal expansion coefficient and thermal conductivity of the weld metal should be basically consistent, so as to avoid thermal stress in the joint during high-temperature operation.