1. Chemical composition
Inconel 600 is a nickel-based solid solution strengthened high-temperature alloy, belonging to the Ni-Cr-Fe alloy series. Its chemical composition (weight percentage) is typically in the following range:
- Ni: ≥72%
- Cr: 14.0~17.0%
- Fe: 6.0~10.0%
- Others: C≤0.15%, Mn≤1.0%, Si≤0.5%, S≤0.015%
The alloy mainly provides an excellent corrosion-resistant base through high nickel content, chromium enhances oxidation resistance and corrosion resistance, and iron optimizes processing performance and cost balance. Its chemical composition complies with international standards such as ASTM B166 and ASME SB-166.
2. Comparison with other grades
-Inconel 600 is a nickel-chromium-iron-based solid solution strengthened alloy (Ni≥72%, Cr 14-17%, Fe 6-10%). Its performance depends on the balance between the corrosion resistance of the high nickel base and the oxidation resistance of the chromium iron, and is suitable for medium and high temperature corrosion environments.
-Inconel 625 is a high-molybdenum-niobium solid solution strengthened nickel-based alloy (Ni≈58%, Cr 20-23%, Mo 8-10%, Nb 3.15-4.15%), which can enhance local corrosion resistance (pitting/crevice corrosion) and does not require post-weld treatment after welding.
-Inconel 718 is a precipitation hardened nickel-based alloy with a room temperature tensile strength of up to 1275 MPa, which is 2.3 times that of 600. This strengthening mechanism allows 718 to maintain 80% of room temperature strength at 650°C, while 600 has a strength drop of about 20% at the same temperature. They are the best choice for high temperature and high strength, and are irreplaceable in aerospace and deep-sea engineering.
3. Analysis of key characteristics
-Corrosion resistance
- Strong oxidizing environment: Excellent performance in high-temperature gases containing chlorine, fluorine, and sulfur, and resistance to boiling sulfuric acid, hydrochloric acid, and hydrofluoric acid corrosion with a concentration of ≤50%.
- Intergranular corrosion resistance: By controlling the carbon content (≤0.15%) and heat treatment process, the chromium-poor area caused by the precipitation of chromium carbide at the grain boundary is avoided, meeting the requirements of the ASTM A262 intergranular corrosion test.
- Stress corrosion cracking resistance: The ability to resist chloride ion stress corrosion in high temperature and high pressure water is significantly better than that of austenitic stainless steel (such as 304/316).
-High temperature mechanical properties
- Operating temperature range: -253°C to 1093°C, the maximum short-term oxidation resistance temperature can reach 1177°C.
- Room temperature mechanical properties (annealed state):
- Tensile strength: ≥550 MPa
- Yield strength (0.2% offset): ≥240 MPa
- Elongation: ≥30%
- High temperature strength retention: At 650°C, the tensile strength is still maintained at about 450 MPa, which is suitable for scenes with long-term high temperature loads.
-Processing and welding performance
- Hot processing: Forging/rolling temperature range is 980~1200°C, and it is necessary to avoid staying in the range of 480~870°C for a long time (to prevent σ phase precipitation embrittlement).
- Cold processing: It can be formed by cold rolling, spinning and other processes, with a medium work hardening rate, and requires intermediate annealing (1090~1150°C water cooling) to eliminate stress.
- Welding: Suitable for GTAW (TIG), GMAW (MIG) and electron beam welding. ERNiCr-3 (welding wire) or ENiCrFe-3 (welding rod) is recommended as a welding material. No preheating is required before welding. Annealing can be performed after welding to optimize performance according to needs.
https://www.fanmetalloy.com/nickel-and-alloys/nickel-alloy/nickel-chromium-wire.html
Summary
Inconel 600 has become a key material in aerospace, chemical, nuclear power and other fields due to its high nickel-based corrosion resistance platform and balanced comprehensive performance in the medium temperature range. Its core value lies in: providing better reliability than stainless steel within the range of moderate corrosion intensity and temperature, while having more cost and processing advantages than complex composition alloys (such as 625, 718).
