The base material of the corrosion-resistant alloy composite equipment does not come into contact with the medium; then why is Q345R (R-HIC) still used?
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This post mentions that corrosion-resistant alloy composite materials were used for the first time in this application, specifically the NS1402+Q345R (R-HIC) corrosion-resistant alloy bimetallic composite. I would like to ask: since the base material does not come into contact with the medium, why was Q345R (R-HIC) still chosen? Are there any special considerations? 【Ten Years of Rapid Development in Chemical Engineering Equipment】Corrosion-resistant alloy composite material equipment for the development of ultra-high sulfur content gas fields from 1998 to 2023 https://bbs.hcbbs.com/thread-4176937-1-1.html (Source: Haichuan Network)
This post was last edited by xlxuiin on 2023-7-4 at 13:06. Some composite materials require the substrate to bear the main loads, necessitating high strength; there are also specific requirements regarding the particles, whiskers, short fibers, etc., in the substrate. The test items for Q345RHIC material include: tensile testing, bending testing, properties in the thickness direction, grain size, Brinell hardness, ultrasonic testing, HIC testing, impact testing, high-temperature tensile testing, SSCC testing, melting analysis, and finished product analysis. Smelting process for Q345RHIC material: electric furnace + secondary refining; Ca treatment is carried out during the smelting process, and it should be an essentially fine-grained steel with an actual grain size of grade 5 or above.
The owner has no financial constraints; perhaps the original design called for Q345R (R-HIC), and now, with the technical upgrades, composite panels are being used. Some designers simply add an NS1402 layer on top of them and that’s it