|"CAN WE WELD MP35N 2" THICK PLATE TO 2" THICK AISI 4130 METAL PLATE? WHAT WILL BE THE POSSIBLE MICRO & PROPERTIES IN THE HEAT AFFECTED ZONE AND WELD REGION?"
Generally speaking, that material combination you are trying to join should weld just fine. However we cannot determine the metallurgical properties until we have first welded this particular application ourselves, as the 2” material thicknesses you are using may become a point of concern due to the amount of material being melted and/or heated.
Also keep in mind is that 4130 often requires post weld heat treatment (PWHT) in order to regain acceptable mechanical properties.