Welding SUS316 Plate to ZG35CrMo

What is the Chinese sub-contractor's reasoning?

His reasons..."very difficult to weld"..."ZG35CrMo same like AISI4140, very high carbon content..will crack"....

But I'd remember sending a AISI4140 shaft for repair by welding up using suitable weld materials. Prior to the weld build-up, the shaft was warmed-up. I believe it was wrapped with a special kind of thermo-blanket. The rest is hisory.

Is there any other cheaper methods? Coz I believe the Chinese sub-contractor will give reasons.

I am not sure of the designations you are referring but I have welded 316L stainless steel to chrome-moly many times when installing s/s thermo wells to chrome moly steam pipe. I qualified a procedure for this using a inconel welding electrode (ER-182 If memory serves me) I am not sure this material is close the same as what you are referring to as I deal with ASME nomenclature on piping/tubing mostly. if I get a chance I will look into these materials more.