Repair welding of final machined ASTM A 743 CB 30

[gustorf]

Hello.

Has anyone experience with weld repairs on martensitic stainless steel castings ASTM A 743 CB 30 (Or material grade GX22CrNi17+QT = 1.4059 in EN Terms)?
As the parts are final machined now, we are looking for procedures WITHOUT PWHT.

So far we are used to simply scrap the parts when we find defects after machining - not very economically and time consuming.

 

[metengr]

CB30 grade is a ferritic stainless steel alloy casting that is chromium, nickel(2%) and iron. This grade is not exceptionally hardened by heat treatment, so you stand a chance of possible weld repairs with no PWHT. Heat input from welding is critical to avoid grain growth and reduced properties of the weld region.

What type of weld repairs area and depth) are you considering? With elevated preheat and proper selection of filler metal (309ss), you may be able to qualify a repair welding procedure.

 

[arunmrao]

I agree with metengr and I reproduce a section from the standard, which is self explanatory.

["b]8.3.2 Post weld heat treatment is not required on the other grades of this specification. When post weld heat treatment is believed necessary for adequate corrosion resistance in the service environment, castings should be ordered in accordance with Specification A 744/A 744M.[/b]"

Scrapping of the parts is the best option. Attempt to salvage, may cause distortion, reduce corrosion resistance or spoil the aesthetics, by discolouration. It all depends on the ground realities, based on the urgency .


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