Cracks occur during the welding of stainless steel Cr20Ni34
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I would like to ask experts how to eliminate the cracks that occur during welding of the collectors in hydrogen production conversion furnaces (made of stainless steel Cr20Ni34), and what causes these cracks? (Operating temperature 750 degrees, 12 years in use; hydrogen removal treatment at 350 degrees for 90 hours prior to welding.) ）
For stainless steel, the main issues are thermal cracking and intergranular corrosion; intergranular corrosion is the result of both the material properties and the manufacturing process. Thermal cracking is mainly caused by high interlayer temperatures, which alter the duplex structure of stainless steel. Regardless of the perspective from which it is analyzed, excessive welding current and high temperatures are the main causes. It is recommended to use 2.5MM electrodes and weld at a low current. If problems persist, the cause should be investigated in terms of the materials used; try using a different batch of electrodes.
Thank you, the problem still hasn’t been resolved.
I need to check this code – it relates to the thermosensitive temperature of stainless steel. The main focus is on quickly passing through that thermosensitive temperature, on how to eliminate residual stresses, and also on properly shaping the welds on the inner and outer walls.