ASTM A217

USED FOR:

Governs chromium-molybdenum alloy steel castings for pressure-containing parts

intended for elevated-temperature service, including valve bodies, bonnets, flanges, fittings, and other cast components.

This is a casting specification, distinct from ASTM A182 forgings and ASTM A106/A335 wrought pipe. It applies specifically to material produced by the casting process.

RELATED STANDARDS:

Sibling specs: ASTM A216 covers carbon steel castings for the same product types in moderate-temperature service where alloy content is not required; ASTM A351 covers austenitic stainless steel castings for corrosion-resistant service; ASTM A352 covers alloy and stainless steel castings for low-temperature service requiring impact toughness. ASTM A217 fills the niche for chromium-molybdenum alloy steel castings intended for elevated-temperature and creep-resistant service.

Design code that invokes it: ASME B16.34 lists ASTM A217 grades as acceptable valve body and bonnet materials with associated pressure-temperature ratings. ASME B31.1 and ASME B31.3 use the allowable stresses published in ASME Section II Part D (SA-217) for pressure design.

Dimensional standards that pair with it: ASTM A217 defines material requirements only. Valve dimensions and pressure-temperature ratings are established by ASME B16.34, face-to-face dimensions by ASME B16.10, flange dimensions by ASME B16.5 where applicable, and butt-weld end preparations by ASME B16.25.

GRADE / TYPE RANGE:

ASTM A217 covers grades including WC1, WC4, WC5, WC6, WC9, C5, C12, and C12A, broadly following the chromium-molybdenum alloy progression found in ASTM A182 forgings, but in cast form.

WC1 and WC4 are lower-alloy grades with moderate chromium and molybdenum contents for elevated-temperature service.

WC5, WC6, and WC9 provide progressively higher chromium and molybdenum contents, improving creep strength, oxidation resistance, and resistance to high-temperature hydrogen attack.

C5, C12, and C12A are the higher-chromium grades, intended for the most demanding elevated-temperature applications requiring improved creep strength and oxidation resistance. Heat treatment requirements vary by grade and are specified individually within ASTM A217.

Grade selection is driven primarily by design temperature, creep requirements, hydrogen service, and compatibility with the adjoining alloy steel piping materials.

DESCRIPTION:

ASTM A217 covers chromium-molybdenum alloy steel castings intended for valves and other pressure-containing components operating at elevated temperatures, produced by conventional casting processes and supplied in the heat-treated condition required for the applicable grade.

The specification establishes chemical composition limits, mechanical property requirements (tensile strength, yield strength, elongation, and reduction of area), and the required heat treatment for each individual grade. Depending on the grade, heat treatment may include annealing, normalizing and tempering, or quenching and tempering.

Mandatory testing includes chemical analysis and tensile testing in accordance with the sampling requirements of the specification. Radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), liquid penetrant testing (PT), impact testing, or hardness testing are not mandatory requirements of the base specification and are only performed when specified by supplementary requirements or by the purchase order.

Weld repair of casting defects is permitted when performed in accordance with ASTM A217 using qualified welding procedures. The extent of repair, required post-weld heat treatment, inspection, and purchaser notification depend on the applicable specification requirements and any supplementary requirements invoked.

Marking includes the manufacturer’s identification, grade designation, and heat identification to ensure complete material traceability.

TYPICAL INDUSTRY USE:

Widely specified for cast valve bodies, bonnets, and other pressure-retaining castings in refining, petrochemical, chemical processing, and fossil-fired power plants operating at elevated temperatures, particularly where the valve material must match adjoining ASTM A335 alloy pipe or ASTM A182 alloy forged components.

IMPORTANT NOTES:

• A common specification mistake is confusing ASTM A217 with ASTM A351. ASTM A217 covers chromium-molybdenum alloy steel castings for elevated-temperature service, whereas ASTM A351 covers corrosion-resistant stainless steel castings.

• Weld repairs are permitted by ASTM A217 but must be performed in accordance with qualified procedures. Repair extent, required heat treatment, inspection, and purchaser notification depend on the specification and any supplementary requirements. For critical service, repair documentation should always be reviewed.

• Supplementary requirements can specify additional NDE (RT, UT, MT or PT), impact testing, hardness testing, or additional chemical and mechanical testing. Project specifications should clearly identify which supplementary requirements are required, since they are not part of the base ASTM A217 specification.

• NACE MR0175 / ISO 15156 compliance is not automatic. Where ASTM A217 castings are used in sour service, hardness limits, heat treatment, weld repair qualification, and any additional requirements must be verified against the applicable edition of NACE MR0175 / ISO 15156.

• From a procurement standpoint, foundry quality, weld repair records, heat treatment documentation, and supplementary NDE reports are often more critical than the base material certification itself, particularly for WC9, C12, and C12A castings used in high-temperature or hydrogen service.