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Super corrosion resistance: high Mo (3-4%), suitable for working conditions in seawater, hydrochloric acid, sulfuric acid, and acetic acid containing Cl ⁻, with a critical pitting temperature (CPT) significantly higher than 316L;
Welding friendly: Low carbon+stable austenite, can be used without heat treatment after welding, high welding efficiency of heat exchanger tube plate flange assembly;
Forging strengthening: Forging ratio ≥ 3, continuous metal flow lines, elimination of internal shrinkage and looseness, better fatigue and impact resistance than cast flanges;
Temperature applicability: Long term use temperature -196 ℃ to 450 ℃, suitable for alternating working conditions of hot and cold media in heat exchangers
element | C | Si | Mn | P | S | Cr | Ni | Mo |
Standard value | ≤0.030 | ≤ 0.75 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0 ~ 20.0 | 1.0 ~ 1.5.0 | 3.0 ~ 4.0 |
performance | Tensile strength (MPa) | Yield strength (MPa) | Elongation (%) | Hardness (HB) |
index | ≥48 5 | ≥ 170 | ≥40 | ≤ 21 7 |
Raw materials: using electric furnace/electric arc furnace+AOD/VOD refining A182 F317L forging billet to prevent hydrogen induced cracking
Forging: Control heating temperature of 1100-1200 ℃, multi-directional forging to ensure grain refinement and no shrinkage/inclusions
Heat treatment: solution treatment at 1040-1100 ℃, water cooling to completely eliminate forging stress and obtain uniform austenite structure
Non destructive testing: 100% UT (ultrasonic) testing of the interior of forgings, RT spot checks, surface MT/PT testing
Chemical/Petrochemical: Hydrochloric acid regeneration unit, sulfuric acid cooler, chlorine gas drying tower;
Marine engineering: seawater heat exchanger, offshore platform condenser;
Pharmaceutical/paper-making: Heating/cooling system for highly corrosive media;
Nuclear power: auxiliary circuit heat exchanger.
