For plates used in high-pressure equipment, should composite sheets be chosen or weld-on coatings?
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For the high-pressure tank of the white oil system, the design pressure is 21.5 MPaG, the design temperature is 300°C; the media involved are oil and hydrogen. The diameter of the tank is 1600, and the material used is 12Cr2Mo1R. It is required that 304 stainless steel be welded on top of this material. The designed thickness of the tank shell is 112 mm. Should the tank be fabricated from sheet metal or from forgings? In this case, is it better to use composite sheets or to apply welding? I hope experts can offer some guidance; thank you!
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From our design experience, it fits right at the edge. It can be segmented or rolled; in our designs, those with a diameter of over 120 generally use forging, and the advantages and disadvantages of forging versus rolling will not be reiterated here. Both thickness and diameter need to be considered.
For designing such equipment, surfacing welding is employed; since a relatively thick stainless steel layer is required (usually 9 mm), it is difficult to ensure 100% proper adhesion of the composite layers. In high-temperature hydrogen environments, even slight deficiencies in adhesion can affect the quality of the equipment.
It is recommended to perform surfacing on the inner surface, as the base layer and the overlay of the composite plate can separate under high temperature and pressure