Question: A doubt regarding the welding of dissimilar steels?
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Thermocouple sleeves are welded to the steam collection header of the power plant boiler; the material of the steam collection header is 12Cr1MoV, while the material of the thermocouple sleeves is 304 stainless steel. Question: What type of welding wire and electrode should be used during welding? Is pre-heating before welding and post-weld heat treatment required?
It is recommended to use nickel-based dissimilar steel welding materials
Welding rod, model E309-16: grade A302, model ENICRFE-3
Dear masters, could you also provide the basis (that is, regulations, standards, etc.)? Thank you!
DLT 868-2014: Procedure for Welding Process Evaluation; DLT 869-2012: Welding Techniques in Thermal Power Plants; DLT 752-2010: Welding Techniques for Dissimilar Steels in Thermal Power Plants. Check these three standards; section 5 of DLT 752, on the selection of welding materials, provides the answer
Many years ago, I saw an English book in the Equipment Department; it was a guide comparing domestic and foreign pipe materials as well as welding materials, along with tables outlining the selection of welding materials for different welding processes. Everything was described in great detail in that book, but I’ve forgotten its title. Perhaps there is also a translation in China titled “I don’t know what it’s called.”
I don’t know how to weld; by using flanges of the same material, welding them together eliminates the risk of cracks due to different materials
SH-T 3526-2015 Code for Welding of Dissimilar Steels in Petrochemical Industries; DL-T 752-2010 Technical Specifications for Welding of Dissimilar Steels in Thermal Power Plants; HG-T 20581-2011 Regulations for the Selection of Materials for Steel Chemical Containers
This is a common issue: there is a lack of communication between the instrumentation team and the piping team. Instrumentation manufacturers usually use stainless steel, which leads to problems with welding different types of steel during installation. However, this is not an issue for reputable boiler manufacturers