| Welding cold-rolled steel to cast iron
Dear Elmer: Is there a way to weld 1018 cold-rolled steel to cast iron? If so, how? James Dear James: You can weld 1018 low-carbon steel to cast iron using shielded metal arc welding (SMAW) and a nickel-based ENiFe electrode. Clean the surfaces before you start. If the joint is highly restrained or if the casting is thick, you might need to preheat the casting. Preheating reduces the cooling rate, residual stress, distortion, and the tendency for cracking. Use short stringer beads. Don't overheat the base metal. The maximum interpass temperature is 600 degrees F. Peening sometimes is used to relieve stress if cracking is a problem. Peening is a mechanical working of metals using impact blows. Peening while the weld deposit is still warm (or as it cools) can help to improve the properties of the deposit and help refine the metallurgical structure. It also assists in relieving shrinkage stresses and in correcting distortion. Peening works the metal and expands it, which counteracts the shrinkage (which causes the cracking) that occurs or may occur during the cooling. | | ||||||
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Hi, You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this. Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime. Again, these simulated no. Of cycles shall be specified in MTC. The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case). One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example. In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...
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