Welding of dissimilar steels
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Can 15CrMo and 20g be welded together? Plan? Thank you
15CrMo can be welded; preheating is required before welding. A preheating temperature specific to 15CRMo should be applied. During interpass welding, the interpass temperature must not be lower than the preheating temperature of 300°C
Thank you! Could the welding process be described in more detail?
The client needs to be more specific – for example, which model and specification of 15CrMo should be welded with which model and specification of 20G; otherwise, it’s not clear what type of process evaluation and process sheet is required.
Material 273 Type 20 and Material 273 Type 15CrMo
For welding 15CrMo and 20g, TIG-J50 is used for the root pass, while J427 electrodes are used for the fill and cover passes. Preheating and post-weld heat treatment are carried out in accordance with the requirements for 15CrMo (preheating at 300°C, tempering at 700°C).
The preheating temperature doesn’t need to be that high.
A preheating temperature of 300 degrees is sufficient; did someone upstairs say to use a 427-degree surface?
If it is a pressure pipeline, it is best not to weld it but to use flange connections instead.