For valves used in polysilicon plants, which is better: a valve core made of 2Cr13 or 304 material?
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I currently have a polysilicon project that requires the purchase of a batch of valves; Nalees ball valves have been selected for this purpose. The process media involved are silicon powder and chlorosilane. The client requires that the valve core be made of 304 material, but the valve supplier says that 2Cr13 is the standard material used for manufacturing these valves, and it is difficult to use 304 material. Question for those familiar with polysilicon: 1. What is the difference between 2Cr13 and 304? Which one has better wear and corrosion resistance? 2. Under these operating conditions, should 2Cr13 or 304 be chosen? (The medium is silicon powder and chlorosilane; the temperature is around 250 degrees, with a pressure of 1–2 kilograms.) Thank you! ! !
304 is equivalent to 1Cr18Ni9. Its chemical composition (%): SUS304 – C≤0.15%, Cr:17–19%, Si≤1.5%, Mn≤2.0%, S/P≤0.05%. The hardness ranges from 350–430 HV. In the production of polysilicon, there are certain requirements regarding the material of pipes and valves, namely low levels of B and P. It must be wear-resistant when transporting silicon powder.
Question: Are the valve cores of the process pipelines and valves in polysilicon production facilities (isolating valves, control valves, manual valves; media: silicon powder, chlorosilane, etc.) made of 2Cr13 material? Thank you! ! !
Some are used, generally in non-corrosive utility media.
It depends on the stage at which it is used. If it is used in the SiHCl3 synthesis stage, 2Cr13 is completely suitable; if it is used after crude distillation, the latter option should be chosen
The valve supplier said that 2Cr13 is the standard material for manufacturing, and it’s difficult to use 304; the supplier cannot provide 304? ? It probably won’t
I personally recommend 304; our factory uses 304 for this purpose. If there are difficulties in using it, imported materials can be used. Otherwise, maintenance issues are a minor problem, but if it causes delays in operation, that would be a serious issue
At such pressures and temperatures, carbon steel is sufficient for the body, but no matter what hardness the valve core has, tungsten carbide spraying is required
It seems that disc valves are now used more frequently in silicon powder in China, and they yield better results as well
2Cr13 is wear-resistant, while 304 has better corrosion resistance
12 pairs of valves for rod reduction furnaces: SPDSDL750 high-purity valves –26.9x1.6
Under these conditions, a ball valve made of 304 material would be slightly better, but neither of these materials is wear-resistant; for the long term, it is more reliable to choose a gate valve.