Questions regarding surfacing welding
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Hello, respected seniors. I would like to ask some questions regarding surfacing here. Because the customer needs to manufacture a steam pressure regulator, the main material required is 32MnMo, while the cladding layer on the inner wall should be made of 321 material. I’m not very familiar with surfacing techniques, so I need to prepare a research report on whether this method is feasible. Could the seniors give some ideas or suggestions?
I also want to know the answer to this question. Good question!
Regulator, alternating hot and cold conditions – I’m not aware of the operating conditions specified in your design; I wonder what the maximum temperature levels are. Is it necessary to take into account the significant differences in thermal expansion between the base layer and the overlay layers? It is best to first weld a transition layer, with the aim of reducing weld dilution and ensuring that there is sufficient austenitic structure in the weld. The ideal material for this purpose is certainly a nickel-based alloy; however, depending on the operating conditions and cost considerations, E309 can also be used for welding. The transition layer should have no fewer than two layers; generally, this means 6 mm. During welding, it is essential to control the fusion ratio, and the process parameters must be appropriate. For double-layer welding, use 321; normal welding methods will suffice. Pay attention to the preheating issue when necessary. In terms of welding methods, it depends on the equipment available; electric welding is the simplest and ensures good quality. Tungsten inert gas welding is another option, but it’s more expensive and less efficient. For submerged arc welding, special attention must be paid to the fusion ratio. There is also information on this topic available online, in the form of papers and books; you can refer to the parameters provided there. Also, there’s a small issue: is the material of the main body indeed called 32MnMo?
Thank you to this senior; the main material should be 20MnMoIII – I got it wrong. A pressure regulator for testing, with a design pressure of 17.32 MPa and a design temperature of 375 degrees Celsius. At the moment, I’m thinking about which companies in China are good at performing this kind of surfacing. I know Dongguan Boiler, Harbin Electric, and Xi’an Nuclear Power; do any experienced colleagues have any other manufacturers to recommend?
I also thank this senior for their guidance.
Looking at the parameters, your industry is really special. Following your line of thought, I can only say that I’ve heard of Shangdian and Yizhong
If surfacing is required, you may refer to Zhengzhou Wanda Heavy Industry Co., Ltd., which uses the hot-wire TIG welding process along with equipment from Austrian company Fronius to perform surfacing on INCONEL 625; contact number: 18638730687