Heat treatment process for composite plate pressure vessels
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Our company is manufacturing a pressure vessel, with the main material being 15CrMoR combined with 304. I would like to ask the experts about the heat treatment process for this material
It should be noted that the heat treatment temperature must not exceed the sensitization temperature of 304.
In a sense, this is incorrect. 15CrMoR is a steel that hardens easily; after the composite plates are combined, significant stresses arise in the steel, and normalizing 15CrMoR is necessary to eliminate these stresses. After normalizing, since 15CrMoR is a steel that hardens easily, it must undergo tempering at around 700 degrees to remove the hardened structures within the steel. On the other hand, 0Cr18Ni9 is a regular austenitic stainless steel, and around 700 degrees is the temperature at which this steel becomes most sensitive to sensitization. Given that the thickness of the steel plate using 15CrMoR is likely not very thin, the sensitization time (i.e., the tempering time) will be quite long. As a result of such treatment, the corrosion resistance of 0Cr18Ni9 becomes extremely poor. It is likely that manufacturers do not use this combination of materials; instead, ultra-low carbon grades resistant to sensitization are used. It is recommended to discuss this matter with the design team to see if using 15CrMoR together with 00Cr19Ni10 or 304 would work – it is likely that it would have the same issues as 0Cr18Ni9
OP, how thick is this 15CrMoR+304?
Is there any difference between composite 00Cr19Ni10 and composite 0Cr18Ni9?
Has anyone done it before? I need it urgently too
Since 00Cr19Ni10 has an ultra-low carbon content, it has better resistance to sensitization. 0Cr18Ni9, on the other hand, is prone to sensitization. Steel plates that combine 15CrMoR with 0Cr18Ni9 require heat treatment before leaving the factory due to the explosive processes used in their fabrication; however, after this treatment, 0Cr18Ni9 loses its properties as stainless steel and thus fails to maintain its corrosion-resistant characteristics. For plates of such thickness, it’s likely that steel manufacturers won’t be able to produce them. You might want to consult with steel manufacturers. Hehe, I’m also a designer – maybe with the advances in technology, steel manufacturers will be able to produce such plates after all＾＿＾.
Is there any difference between composite 00Cr19Ni10 and composite 0Cr18Ni9? Well, this is mainly because when austenitic stainless steels are cooled slowly in the range of 400 to 850 degrees, there is enough time for high-chromium carbides such as Cr23C6 to precipitate and accumulate at the grain boundaries. This results in chromium-deficient areas adjacent to these carbides, which leads to a tendency for intergranular corrosion in corrosive environments. The use of ultra-low carbon content can reduce this tendency
Refer to Section 6 of HG20584-98: lol
Due to its large diameter, a 16MnR+304L composite plate head could only be formed by cold spinning, according to the head manufacturing factory. Can the heat treatment after cold spinning be carried out according to the heat treatment specifications for the base material? Does it have a significant impact on 304L cladding?
Is it possible to heat-treat 50mm 15CrMoR and then weld on 309L+347?
Is it possible to heat-treat 50mm 15CrMoR and then weld on 309L+347?