A351 CK20

ASTM

A351 CK20

ASME

SA351 CK20

UNS -Cast

J94202

Overview

CK20 is an austenitic stainless steel casting alloy defined by ASTM A351/A351M, primarily intended for high-temperature, pressure-containing components such as reformer tubes, manifolds, and heat exchanger parts. With a nominal composition of 25% chromium and 20% nickel, CK20 offers excellent resistance to oxidation, carburization, and sulfidation in elevated-temperature service environments. Its stable austenitic microstructure ensures good creep resistance and structural integrity under long-term thermal exposure, making it a preferred material in the petrochemical, refining, and heat treatment industries. CK20 is widely used where both high-temperature strength and corrosion resistance are critical for reliable performance.

Chemical Composition

Carbon

0.04 - 0.20%

0.04 - 0.20%

0.04 - 0.20%

Manganese

1.50% Max

Silicon

1.75% Max

Phosphorus

0.04% Max

Sulfur

0.04% Max

Chromium

23.00 - 27.00%

Nickel

19.00 - 22.00%

Molybdenum

0.50% Max

Mechanical Properties

Yield Strength

28 ksi Min

Tensile Strength

65 ksi Min

Elongation at 2 in

30% Min

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© Alloy Casting Industries Ltd 2025

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© Alloy Casting Industries Ltd 2025

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© Alloy Casting Industries Ltd 2025