Explosive stainless steel clad steel plate vessel heat treatment Explosive stainless steel clad steel plate is used more and more widely in the pressure vessel industry due to its excellent corrosion resistance, perfect combination of mechanical strength and reasonable cost performance. However, the heat treatment problem of this material It should also attract the attention of pressure vessel designers. Pressure vessel designers usually pay more attention to the technical index of the composite plate is its bonding rate, and the heat treatment of the composite plate is often considered very little or thinks that this problem should be considered by the relevant technical standards and manufacturers. The process of explosive processing of metal composite panels is essentially a process of applying energy to the metal surface. Under the action of high-speed pulses, the composite material obliquely collides with the substrate. In the state of the metal jet, a zigzag composite interface is formed between the composite metal and the base metal to achieve interatomic bonding. The base metal after explosive processing has actually undergone a strain-strengthening process. As a result, the tensile strength σb increases, the plastic index decreases, and the yield strength value σs is not obvious. Whether it is Q235 series steel or 16MnR, after explosive processing and then testing its mechanical performance indicators, it shows the above-mentioned strain strengthening phenomenon.
In this regard, both the titanium-steel composite plate and the nickel-steel composite plate require that the composite plate be subjected to stress relief heat treatment after explosive compounding. The 99 edition "Capacity Regulations" also has clear regulations on this, but there is no such regulation for explosive composite austenitic stainless steel plates. In the current relevant technical standards, the question of whether and how to heat the austenitic stainless steel plate after explosive processing is more ambiguous. GB8165-87 "Stainless steel clad steel plate" stipulates: "According to the agreement between the supplier and the demander, it can also be delivered in hot rolled or heat-treated state." It can be supplied by leveling, trimming or cutting. According to the requirements of the buyer, the composite surface can be pickled, passivated or polished, and can also be supplied under heat treatment." There is no mention of how to perform heat treatment. The main reason for this situation is still the aforementioned austenitic stainless steel producing intergranular corrosion sensitized area problem. GB8547-87 "Titanium-steel composite plate" stipulates that the heat treatment system of stress-relieving heat treatment of titanium-steel composite plate is: 540℃±25℃, heat preservation for 3 hours. And this temperature is just within the sensitization temperature range of austenitic stainless steel (400℃-850℃).
Therefore, it is more difficult to give clear regulations on the heat treatment of explosive composite austenitic stainless steel plates. In this regard, our pressure vessel designers must have a clear understanding, give full attention, and take corresponding measures. First of all, 1Cr18Ni9Ti should not be used for composite stainless steel, because compared with low-carbon austenitic stainless steel 0Cr18Ni9, it has a higher carbon content and is more prone to sensitization, which reduces its resistance to intergranular corrosion. In addition, when the shell and head of the pressure vessel made of explosive composite austenitic stainless steel plate are used in harsher conditions, such as high pressure, pressure fluctuations, and extremely hazardous media, 00Cr17Ni14Mo2 should be used. Ultra-low carbon austenitic stainless steel can minimize the possibility of sensitization. And should clearly put forward the heat treatment requirements of the composite board, and negotiate with the relevant parties to determine the heat treatment system, so as to achieve a certain amount of plastic storage for the base material and the composite material to have the required corrosion resistance.
In this regard, both the titanium-steel composite plate and the nickel-steel composite plate require that the composite plate be subjected to stress relief heat treatment after explosive compounding. The 99 edition "Capacity Regulations" also has clear regulations on this, but there is no such regulation for explosive composite austenitic stainless steel plates. In the current relevant technical standards, the question of whether and how to heat the austenitic stainless steel plate after explosive processing is more ambiguous. GB8165-87 "Stainless steel clad steel plate" stipulates: "According to the agreement between the supplier and the demander, it can also be delivered in hot rolled or heat-treated state." It can be supplied by leveling, trimming or cutting. According to the requirements of the buyer, the composite surface can be pickled, passivated or polished, and can also be supplied under heat treatment." There is no mention of how to perform heat treatment. The main reason for this situation is still the aforementioned austenitic stainless steel producing intergranular corrosion sensitized area problem. GB8547-87 "Titanium-steel composite plate" stipulates that the heat treatment system of stress-relieving heat treatment of titanium-steel composite plate is: 540℃±25℃, heat preservation for 3 hours. And this temperature is just within the sensitization temperature range of austenitic stainless steel (400℃-850℃).
Therefore, it is more difficult to give clear regulations on the heat treatment of explosive composite austenitic stainless steel plates. In this regard, our pressure vessel designers must have a clear understanding, give full attention, and take corresponding measures. First of all, 1Cr18Ni9Ti should not be used for composite stainless steel, because compared with low-carbon austenitic stainless steel 0Cr18Ni9, it has a higher carbon content and is more prone to sensitization, which reduces its resistance to intergranular corrosion. In addition, when the shell and head of the pressure vessel made of explosive composite austenitic stainless steel plate are used in harsher conditions, such as high pressure, pressure fluctuations, and extremely hazardous media, 00Cr17Ni14Mo2 should be used. Ultra-low carbon austenitic stainless steel can minimize the possibility of sensitization. And should clearly put forward the heat treatment requirements of the composite board, and negotiate with the relevant parties to determine the heat treatment system, so as to achieve a certain amount of plastic storage for the base material and the composite material to have the required corrosion resistance.
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