1. ASTM International Standards (U.S. Standards, Widely Used Globally)
ASTM standards are the most commonly referenced technical specifications for Inconel 625 in international trade, with clear requirements for chemical composition, mechanical properties, heat treatment, and inspection methods for each product form:
ASTM B443: Specification for nickel-chromium-molybdenum-columbium [niobium] alloy (UNS N06625) and nickel-chromium-cobalt-molybdenum alloy (UNS N06022) plate, sheet, and strip. This standard applies to flat products of Inconel 625, defining dimensional tolerances, tensile properties, and corrosion test requirements.
ASTM B444: Specification for nickel-chromium-molybdenum-columbium [niobium] alloy (UNS N06625) seamless pipe and tube. It covers seamless pipes and tubes, including requirements for hydrostatic testing, eddy current testing, and grain size control.
ASTM B446: Specification for nickel-chromium-molybdenum-columbium [niobium] alloy (UNS N06625) rod and bar. This standard is for round, square, and hexagonal bars, stipulating mechanical properties such as tensile strength and elongation in the solution-annealed state.
ASTM B564: Specification for nickel alloy forgings. It applies to Inconel 625 forgings used in high-temperature and corrosive environments, with strict regulations on forging processes, heat treatment cycles, and non-destructive testing (NDT) methods.
ASTM B670: Specification for nickel-chromium-molybdenum-columbium [niobium] alloy (UNS N06625) welded pipe and tube. It targets welded pipes and tubes, specifying welding processes, filler metal selection, and post-weld heat treatment (PWHT) requirements (if needed).
ASTM B829: Specification for nickel-chromium-molybdenum-columbium [niobium] alloy (UNS N06625) wire. It is used for wires processed into fasteners, electrodes, or 3D printing raw materials, with requirements for diameter tolerance and tensile properties.
2. ASME Standards (For Pressure Vessel and Boiler Applications)
ASME standards are derived from ASTM standards but are specially adapted for pressure-bearing equipment, widely used in petrochemical, power generation, and nuclear industries:
ASME SB443: The pressure vessel version of ASTM B443, applicable to Inconel 625 plates and sheets used in pressure vessel shells, heads, and heat exchanger components, requiring compliance with ASME Boiler and Pressure Vessel Code (BPVC) Section VIII.
ASME SB444: Corresponding to ASTM B444, it is used for seamless pipes and tubes in pressure-bearing systems, with additional requirements for burst pressure testing and material traceability.
ASME SB564: The forging standard for pressure vessel applications, which strictly controls the internal quality of forgings to avoid defects such as shrinkage cavities and cracks that affect pressure-bearing safety.
3. European Standards (EN Standards, EN 2.4856 is the Material Number of Inconel 625)
European standards are mandatory for products sold in the EU market, with unified technical requirements across member states:
EN 10088-1: General requirements for stainless steels and nickel alloys for structural purposes, specifying the basic classification and marking rules of Inconel 625 (material number: 2.4856).
EN 10088-3: Specific requirements for plates, sheets, and strips of stainless steels and nickel alloys, covering dimensional tolerances and mechanical properties of Inconel 625 flat products.
EN 10272: Specification for stainless steel bars and rods for pressure purposes, applicable to Inconel 625 bars used in high-pressure equipment.
EN 10216-5: Specification for seamless steel tubes for pressure purposes - Part 5: Nickel alloy tubes, which defines the technical parameters of Inconel 625 seamless pipes for pressure-bearing applications.
EN 10217-7: Specification for welded steel tubes for pressure purposes - Part 7: Nickel alloy tubes, applicable to Inconel 625 welded pipes.
4. National Standards of Other Countries/Regions
China National Standards (GB):
GB/T 15007: Nickel-base alloy designation, which equates Inconel 625 to the Chinese brand NS336.
GB/T 14992: Nickel and nickel alloy rods and bars, specifying the technical requirements for NS336 (Inconel 625) bars.
GB/T 20590: Nickel and nickel alloy plates and sheets, covering the production standards of NS336 plates and sheets.
Japanese Industrial Standards (JIS):
JIS H4551: Nickel alloy plates, sheets and strips, which includes the requirements for Inconel 625 flat products.
JIS H4552: Nickel alloy bars, applicable to Inconel 625 bars.
Russian Standards (GOST):
GOST 28983: Nickel alloys for sheets, strips and plates, which defines the corresponding grade of Inconel 625 in the Russian standard system.
5. Industry-Specific Standards
NACE MR0175/ISO 15156: Standard for materials resistant to sulfide stress cracking (SSC) in sour oil and gas environments. Inconel 625 that meets this standard can be used in equipment handling H₂S-containing fluids, requiring strict control of impurity elements and heat treatment processes.
AMS 5599: Aerospace Material Specification issued by SAE International, applicable to Inconel 625 plates, sheets, and strips for aerospace engine components, with higher requirements for material purity and mechanical property consistency.
