What type of welding electrode is needed for welding 45# medium-carbon steel and 20# carbon steel?
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Which welding electrode should be chosen for welding 45# medium-carbon steel and 20# carbon steel? What welding process is required? It’s urgent. If any fellow travelers know, please let me know.
I’m not sure about the conditions of the workpiece you need to weld. For ordinary components, using J507 welding rod in manual arc welding is sufficient; in cases where there is a high degree of constraint, post-weld stress-relief heat treatment is required.
The workpiece is a single-exit lens pad made of 45# steel, and it is necessary to drill holes in the lens pad in order to weld high-pressure pipes made of 20# steel onto it.
Generally, low-hydrogen welding electrodes with strong desulfurization capability, low diffused hydrogen content in the deposited metal, and good plasticity and toughness are selected. When equal strength is required, select low-hydrogen electrodes of the appropriate grade; when equal strength is not required, use low-hydrogen electrodes with a strength lower than that of the base material ； If preheating of the base material is not allowed during welding, in order to prevent cold cracks in the HAZ, austenitic stainless steel electrodes can be used to obtain a weld structure with good plasticity and strong crack resistance, such as A307, A302, A407, A402, etc.
thj422 diameter 3.2-4.0 e4303 diameter 3.2-4.0
I’ve encountered this situation; I used A307, and A302 works as well.
Either J472 or J507 will work; preheating before welding, welding with low heat input, and slow cooling after welding. Heterogeneous welds are also acceptable, but they are probably not the recommended approach.
Any welding electrode suitable for medium carbon steel can be used.
Reply to 6# dongyihao2008: Austenitic welding electrodes have good plasticity
Either J507 or A307 can be used; it depends on whether your company has the capability for welding procedure qualification
The principle for welding dissimilar steels is generally to match the strengths; J427 will suffice for this purpose. Welding rods with slightly higher strength, such as J507, or those of other strength levels can also be used. It is acceptable for the strength of the welding rod to be between 20# and 45#, which means there is a wide range of options available. 45# steel must be preheated before welding, and appropriate heat retention is required after welding; heat treatment is not necessary.