Nickel alloy steels, due to their excellent corrosion resistance, high-temperature strength, and mechanical properties, are widely used in aerospace, petrochemical, energy, and marine engineering applications. However, due to differences in performance requirements, testing methods, and classification standards for nickel alloy steels across different countries and regions, several mainstream international standards have emerged, including the US ASTM/ASME, the EU EN, the international ISO, the Japanese JIS, and the Chinese GB. This article will comprehensively compare and analyze these standards from the perspectives of chemical composition, mechanical properties, corrosion resistance, manufacturing processes, and application areas, to help engineers and purchasers better understand and select appropriate nickel alloy steels.

1. Overview of major international standard systems

01. ASTM/ASME

Nickel alloy steel standards developed by the American Society for Testing and Materials (ASTM) and the American Society of Mechanical Engineers (ASME) have a wide range of influence worldwide, such as ASTM B160 (nickel rod), ASTM B162 (nickel plate), and ASTM B163 (nickel pipe). ASME standards (such as the ASME SB series) are generally based on ASTM standards but add additional requirements for pressure vessel and piping applications.

02. EN

European standards (EN), developed by the European Committee for Standardization (CEN), cover the chemical composition, mechanical properties, and test methods of nickel alloy steels, such as EN 10095 (heat-resistant nickel alloys) and EN 10216-5 (nickel alloy steel pipes). EN standards are often harmonized with ISO standards, applicable to the EU market, and adopted by many countries around the world.

03. ISO

Nickel alloy steel standards developed by the International Organization for Standardization (ISO), such as ISO 6208 (Nickel and nickel alloy bars) and ISO 6207 (Nickel and nickel alloy wire), have a high degree of international applicability, but some standards may reference ASTM or EN content.

04. JIS

Nickel alloy steel standards in the Japanese Industrial Standards (JIS), such as JIS G4901 (nickel and nickel alloy rods) and JIS G4902 (nickel and nickel alloy plates), are mainly applicable to the domestic Japanese and Asian markets, and some standards are compatible with international standards.

05. GB

Nickel alloy steel standards in China's national standards (GB), such as GB/T 2882 (nickel and nickel alloy rods) and GB/T 2881 (nickel and nickel alloy plates), have gradually been aligned with international standards in recent years. However, differences still exist in some special grades and test methods.

2. Comparison of chemical composition

There are significant differences in the chemical composition requirements of nickel alloy steels among different standards, especially the content ranges of key elements such as nickel (Ni), chromium (Cr), molybdenum (Mo), and iron (Fe).

Key differences:

ASTM/ASME has stricter control over the Mo and W content of certain special alloys (such as the Hastelloy series) for use in extremely corrosive environments. EN/ISO focuses more on the material's weldability and formability, and some grades may have slightly higher Fe content.

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3. Comparison of mechanical properties

Mechanical properties (such as tensile strength, yield strength, and elongation) are important bases for the selection of nickel alloy steels. Different standards have different requirements for heat treatment status and test conditions.

Key differences:

ASTM/ASME has stricter requirements for high-temperature endurance strength and creep properties, making it suitable for boilers and aircraft engines. EN/ISO focuses more on the cold working properties of materials, with some standards providing mechanical data in the cold-rolled or cold-drawn state.

4. Corrosion resistance comparison

The corrosion resistance of nickel alloy steels depends primarily on their chemical composition, particularly the content of elements such as Cr, Mo, and Cu. Different standards use different testing methods for corrosion resistance (e.g., intergranular corrosion, pitting corrosion, and stress corrosion).

Key differences:

ASTM has stricter testing requirements for extreme corrosive environments (such as hydrochloric acid and sulfuric acid) and is suitable for the chemical industry. EN/ISO focuses more on the material's resistance to intergranular corrosion and is suitable for the nuclear industry and marine engineering.

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5. Comparison of manufacturing processes and application areas

Nickel alloy steels of different standards also differ in manufacturing processes (such as forging, rolling, welding) and application areas.