When the composite plate head is cold formed, the surface of the cladding after pressing will always leave scratch marks, and the local thickness will be reduced, especially near the R transition area. The repeated rolling of the cladding is also prone to wrinkles. If the composite board is defective during explosive compounding, the cladding is easily peeled off. In addition, the material of the cladding dual-phase steel has high strength, high hardness, and low thermal expansion. Performance, yield strength is twice higher than ordinary stainless steel, and has enough plastic toughness during forming, and it is generally difficult to control the size in cold forming.
When the dual-phase steel clad plate head adopts hot forming, it is generally necessary to strictly control the heating temperature and holding time. After forming, it should be cooled quickly to minimize the precipitation of σ phase at 500~925℃ and high temperature embrittlement at 400~500℃. Precipitatingα'phase produces brittleness at 475°C. The production of these two phases will affect the toughness of the steel, and the local corrosion resistance will decrease, which is detrimental to the corrosion resistance of the material. The cladding duplex stainless steel of the head is designed to be corrosion resistant, so In the manufacturing process of the head, it is difficult for the mechanical properties of the material, the corrosion resistance of the coating and the geometric size of the head to guarantee and meet the standard requirements at the same time, which will inevitably bring difficulties to the manufacturing of the head. According to the previous manufacturing experience of composite plate material heads such as SA-516Gr.70+SA-240-304L and the recommendations of the head manufacturer, if the composite plate head is integrally formed, it is best to choose the hot press type. Therefore, the forming method of the composite plate head adopts hot pressing type, and brings a test plate and the head plate into and out of the furnace at the same time, and sprays and cools immediately after forming to avoid the precipitation of brittle phase. Perform physical and chemical tests on the furnace test panel to verify whether the mechanical properties and corrosion resistance of the composite panel material are damaged during the hot pressing process.