Advice on welding 8630 casting

[teb1]

I have a project where the initial metalurgical sample indicated a rather "soft" steel casting with a fairly low hardnes,83HRB.

I submitted a larger section for analysis and the larger section showed a much higher hardness away from the surface ,253HRB, and therefore a higher tensile strength. The material was identified as a 8630 casting.

I plan to locally preheat with resistance blankets and maintain a preheat around the repair area of approxiamtely 450-500F. I plan to use a temper bead method, where I butter the the surfaces of the bevel with minimum heat input, grind part of the thicknes of the butter pass away and then butter again with little more heat input, grind part of that layer away and then fill with bevel out.

I can't perform a PWHT of the whole casting. I could perform a local but am hesitant because of the complexity of the geometry.

Any thoughts from group would be appreciated.

Thanks,

Tommy

 

[metengr]

Yes, my advice would be to have the welder(s) practice the half bead temper bead method before use. The half bead technique, and it's sister technique the temper bead method are based strictly on welder experience, and the welder(s) should be qualified on using this method. Do you have a qualified procedure to at least conduct this weld repair? If not, I would suggest you develop a WPS for this and qualify it for use.
NDT - wet fluorescent MT should be specified before welding and after the completion of welding for final acceptance of the repair. Make sure you maintain your stated preheat and watch interpass temperatures.