RAYCHIN LIMITED

Inconel Washers – Types & Configurations

Critical Applications of Inconel Washers

International Standards & Global Designations – Inconel Washers

RAYCHIN LIMITED manufactures Inconel washers from material conforming to the most widely used national and international specifications. All material is traceable to the mill.

Chemical Composition (Weight %) – Inconel Alloys for Washers

Our Inconel washers are produced from melts conforming to the following limits per ASTM/ASME/AMS.

Inconel 600 (UNS N06600 / 2.4816)

Inconel 625 (UNS N06625 / 2.4856)

Inconel 718 (UNS N07718 / 2.4668)

Inconel X-750 (UNS N07750 / 2.4669) – Typical for Spring Washers

Metallurgical note: High nickel content (≥50%) provides exceptional resistance to chloride stress corrosion cracking. Chromium (14–23%) ensures oxidation resistance up to 1150°C. Molybdenum (in 625) and Nb+Ti (in 718/X-750) contribute to solid‑solution strengthening and precipitation hardening. Inconel X-750 and 718 are precipitation-hardenable, allowing spring washers to maintain high load capacity at elevated temperatures. Inconel 625 is solid-solution strengthened and requires no heat treatment for corrosion resistance.

Complete Mechanical & Physical Properties – Inconel Washers (MPa / ksi)

Inconel washers are supplied in solution annealed (600, 625, 601) or age‑hardened (718, X‑750) condition per specification. Data represent typical values based on ASTM, AMS, and industry standards. ksi values (kilopound per square inch) are provided alongside MPa.

Mechanical Properties – Typical Values (room temperature) for Inconel Washers

Physical Properties (typical) – Inconel Washers

High‑Temperature Performance of Inconel Washers

Inconel superalloys retain significant strength at elevated temperatures, making Inconel washers ideal for furnace fixtures, gas turbine joints, and exhaust system assemblies. Data below demonstrate the superiority of Inconel 718, 625, and 601 for high‑T applications.

Elevated Temperature Strength – Comparison by Grade

At 650°C, Inconel 718 retains about 80% of its room‑temperature tensile strength, outperforming many other alloys. Inconel X-750 is specifically designed for spring applications at elevated temperatures, offering excellent relaxation resistance. Inconel 625 and 601 provide outstanding resistance to oxidation and carburization at even higher temperatures, making them excellent choices for high‑temperature washers in furnace and heat treat applications.

High‑Temperature Limits & Oxidation Resistance

Exceptional Corrosion Resistance of Inconel Washers

The high nickel and chromium content imparts resistance to a wide range of corrosive media: chlorides, acids, and alkalis. Inconel 625 and Inconel 718 washers are particularly resistant to pitting and crevice corrosion in seawater and sour environments.

• Chloride stress corrosion cracking (SCC): All Inconel grades exhibit high resistance due to Ni >40%; immune to chloride-ion SCC.
• Sulfuric & Hydrochloric acids: Inconel 625 shows exceptional performance in reducing acids (Mo addition).
• Sour service (H₂S): Inconel 625 & 718 qualified per NACE MR0175/ISO 15156 for oil & gas.
• Oxidation & carburization: Inconel 601 outperforms due to aluminum addition.
• Seawater: Inconel 625 resists pitting and crevice corrosion, used extensively in marine fasteners.
• High-purity water & alkalis: Inconel 600 offers excellent corrosion resistance in nuclear applications.
• Dry chlorine & hydrogen chloride: Inconel 600 resists attack up to 650°C.

Manufacturing Standards – Inconel Washers

All Inconel washers are manufactured and tested to meet:

We offer surface finishes: passivation (ASTM A967), silver plating (AMS 2410 for anti‑seize), PTFE coating, electropolish, and zinc‑nickel plating. Full traceability and destructive/non‑destructive testing available (UT, MPI, PMI).