ASTM A217 Grade WC9

STANDARDASTM A217FORMCastingEN 10213G17CrMo9-10 · 1.7379 (near)Wrought counterpartF22

2¼Cr–1Mo alloy steel casting. Higher creep strength than WC6; the classic body material for superheated steam lines in power plants.

Rp0.2 · MPa: ≥ 275
Rm · MPa: ≥ 485
TEMPERATURE: −29 … +593 °C
COST

Representative sample of WC9: machined top face and as-cast side — REPRESENTATIVE IMAGE

Chemical composition

C0.05–0.18

Mn0.40–0.70

P≤ 0.04

S≤ 0.045

Si≤ 0.60

Cr2.00–2.75

Mo0.90–1.20

Ni≤ 0.50

%. ASTM A217. Residual elements (Cu, W) and their total are limited separately in the standard.

Mechanical properties

STANDARD · CONDITION	Rp0.2 MPa	Rp1.0 MPa	Rm MPa	A %	KV J
ASTM A217 · WC9	275	—	≥ 485	20	—
EN 10213 · G17CrMo9-10 (+QT)	400	—	590–740	18	—

Room temperature, normalized + tempered. Hardness ≤ 241 HB. Z ≥ 35%.

ASME B16.34 pressure-temperature ratings

CLASS · bar	−29 … 38 °C	100 °C	200 °C	300 °C	400 °C	500 °C
Class 150	19.8	17.7	13.8	10.2	6.5	2.8
Class 300	51.7	51.5	48.6	42.9	36.5	28.2
Class 600	103.4	103.0	97.2	85.7	73.3	56.5
Class 900	155.1	154.6	145.8	128.6	109.8	84.7
Class 1500	258.6	257.6	243.4	214.4	183.1	140.9
Class 2500	430.9	429.4	405.4	357.1	304.9	235.0

Standard class, bar. Material group: WC9. Greyed values are outside the material's service range (−29 … +593 °C). Flanged-end ratings end at 538 °C.

Service temperature

−29 °C+593 °C−200−1000100200300400500600700800

This is the limit of the material itself. A valve's service temperature is usually set by the seal and seat materials; product pages give it for each seal option.

Physical properties and heat treatment

HEAT TREATMENT: Normalizing + tempering (≥ 675 °C).

Media suitability GENERAL TREND

Fresh water

Seawater

Steam

Hydrocarbons, oil

Dilute acid

Caustic

Air, gas

Low temperature

Emsal assessment. The final choice is made from corrosion tables, taking concentration, temperature, chloride content and flow velocity into account.

Strengths and weaknesses

Strengths

Higher creep strength than WC6
Standard in superheated steam service

Weaknesses

Preheating and post-weld heat treatment are mandatory
Limited corrosion resistance

Manufacturing and use

ECONOMY: Medium.
MANUFACTURING METHODS: Sand casting + normalizing and tempering
TYPICAL VALVE PARTS: Body · Bonnet

Surface protection

Wet paintIndustrial wet paint systemExternal surface; silicone-based heat-resistant paint is needed at high temperature

Source: ASTM A217. Values compiled and verified by Emsal Vana; for binding values, refer to the current edition of the standard and the material certificate.