Petrochemical
Nickel Alloys for Mixed Acids, Chlorides and Furnace Duty
Industry Overview
Petrochemical service is rarely one corrosive agent. Alkylation carries sulfuric acid, reformers run above 800°C, chlorides arrive in trace amounts through cooling water and catalysts, and process streams mix oxidising and reducing conditions in the same line. TOKO ALLOY supplies the four alloys that cover this space — Hastelloy C-276 and C-22 for mixed and halide-bearing acids, Incoloy 825 for sulfuric and phosphoric service, Inconel 625 and Alloy 601 for high-temperature furnace and reformer sections.
Key Challenges
Mixed Acid Streams — Oxidising and Reducing at Once
Sulfuric, nitric and organic acids arrive together, and the mix can swing between oxidising and reducing conditions with process changes. Hastelloy C-276 handles both ends simultaneously, which is exactly the case where a single-mode alloy fails with no warning.
Wet Chlorine, Hypochlorite and Ferric Chloride
Halide-bearing streams pit and crevice-corrode standard stainless rapidly. Hastelloy C-22's higher chromium (20–22.5% versus 14.5–16.5% in C-276) is the specific answer where ferric and cupric chlorides or wet chlorine dominate — C-276 remains the better choice for reducing acids.
Sulfuric and Phosphoric Acid at Temperature
Concentrated sulfuric acid attacks Ni-Cr-Mo grades from the reducing side. Incoloy 825's controlled copper addition (1.5–3.0%) is what gives it resistance across the concentration range in alkylation and sulfonation units, up to about 540°C.
Reformer and Cracker Furnace Sections
Above 800°C the failure mode changes from wet corrosion to carburisation, sulfidation and metal dusting. Alloy 601 forms a tightly adherent alumina layer that resists all three to 1260°C; Alloy 800H/800HT provides creep and rupture strength to 815°C and 980°C respectively at lower cost.
TOKO ALLOY Solutions
Hastelloy C-276 and C-22 Reactor Piping
ASTM B622/B619 pipe and B626 tube in C-276 (N10276) for reducing mixed acids and wet chlorine; C-22 (N06022) where ferric/cupric chlorides and oxidising media are present. Both are supplied solution-annealed with PMI on 100% of joints.
Incoloy 825 for Acid Service (N08825)
ASTM B423 seamless pipe from 1/8" to 6" OD for sulfuric and phosphoric acid lines, pickling tank heaters and pollution-control scrubbers. Copper-bearing chemistry, resistant to intergranular attack after welding.
Alloy 601 and 800H/800HT for Furnace Sections
Alloy 601 (N06601) tube and bar for reformer and cracker internals where carburisation and metal dusting govern; Alloy 800H/800HT (N08810/N08811) for headers, pigtails and transfer lines where creep strength to 815–980°C is the design driver.
Inconel 625 for High-Temperature Chloride Service (N06625)
ASTM B444 pipe and B446 bar where a single alloy must carry both high temperature (to 980°C) and chloride pitting resistance (PREN > 45) — catalyst handling, high-temperature chlorination and flue-gas desulfurisation hardware.
Recommended Materials Petrochemical
View detailed chemical composition, mechanical properties, and corrosion resistance data for each recommended grade:
Related Products
Need Piping Solutions for Petrochemical?
Tell us about your project requirements and we will recommend the optimal material and product specification.
Request Quote