The main reasons why composite steel plates are generally not heat-treated are, firstly, the different linear expansion coefficients of the two materials; heat treatment might...

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Does the composite material in bg4.png require heat treatment? If so, how should the heat treatment process be formulated? A urea synthesis tower made of composite plates, with a base layer of 75mm thick made of 16MnR, and an overlay layer of 5mm thick made of OOCr17Ni14Mo2. Is post-weld heat treatment required? () a. Yes ； b. Not required ； Explanation 1: Heat treatment at B affects the intergranular corrosion resistance of the cladded material ； Explanation 2: The base material is the one that bears the main pressure loads. With such a thick base layer, the welding stresses are very high; moreover, the stresses inside the cylinder are also significant. Failing to carry out heat treatment after welding creates safety hazards for the equipment. There is information available on the heat treatment of composite panel manufacturing equipment; it seems that ensuring the safety of the equipment should be a priority, before considering issues related to stainless steel sensitization and corrosion. Explanation 3: The reason why a composite steel plate is generally not subjected to heat treatment is mainly that the linear expansion coefficients of the two materials differ, and heat treatment may cause delamination at the composite interface ； Second, the sensitization temperature of stainless steel is exactly the temperature for post-weld heat treatment. The base materials are the main compression-bearing components; without heat treatment after welding, the equipment poses safety risks. The appropriate solutions are, first, to select a suitable heat treatment process, and second, to create welding test specimens of the products in order to specifically evaluate their corrosion resistance after heat treatment.