Welding of 15CrMo and 321 thick-walled pipes

It is determined based on the operating temperature: when the design temperature is below 371 degrees, it is recommended to use austenitic stainless steel welding materials from a cost-effective perspective; whereas when the design temperature is above 371 degrees, nickel-based welding materials are advised. In the weld area, to reduce the fusion ratio and minimize the dilution of the weld metal, a large groove is used, along with low current and rapid multi-pass welding. Welding materials should primarily be chosen such that their Ni and Cr contents are higher than those of the base material. For 15CrMo materials, preheating to above 150 degrees is necessary before welding, and it is advisable to start welding from the 15CrMo side first. It is recommended to use welding materials: wire H1Cr26Ni21 (ER310) and electrode A407 (E310-15) ； If the temperature is low and lower corrosion resistance is required, the following can also be used: welding wire HCr24Ni13 (ER309), and electrode A307 (E309-15) ； It is recommended to use this when the temperature is above 371 degrees; the welding wire is ERNiCrFe-1, and the electrode is Ni307 (ERNiCrFe-1).