ASTM A182 F9 and ASTM A336 F9 Forgings, 9Cr-1Mo Alloy Steel

What ASTM A182 F9 is

F9 belongs to the chrome-moly family, the steels that piping and pressure vessel engineers turn to once service temperature passes the roughly 425 °C ceiling of plain carbon steel. Chromium handles high-temperature oxidation and the sulphidic corrosion found in refinery streams. Molybdenum keeps strength up at temperature and slows softening during tempering.

Inside that family F9 sits between the 5 % chromium grade F5 and the modified 9Cr-1Mo-V grade F91. It shows up most often in catalytic reformer and hydroprocessing service, where hydrogen and hot hydrocarbon rule out the lower-alloy grades.

Two ASTM specifications cover F9 forgings. The chemistry is the same in both, but they are not interchangeable on paper:

• ASTM A182 / A182M covers forged or rolled alloy and stainless steel pipe flanges, forged fittings, valves and parts for high-temperature service. Order to A182 when the part is a piping component.
• ASTM A336 / A336M covers alloy steel forgings for pressure and high-temperature parts: boilers, pressure vessels and associated equipment. Order to A336 for heavy vessel forgings such as tubesheets, shells and heads.

Chemical composition of ASTM A182 F9

ASTM A336 F9 takes its heat analysis limits from ASTM A335 / A335M Grade P9, with product analysis tolerances given in A336 Table 1. Confirm values against the edition named in your purchase order.

Mechanical properties

Which minimum tensile figures apply depends on the specification the forging is ordered to. Both sets are given below, because this one catches people out.

A182 carries its own tensile table for forged piping components. A336 instead adopts the chemical, tensile, heat treatment and marking requirements of A335 / A335M for the matching pipe grade. Same steel, different acceptance criteria. Real heat-treated properties normally land well above both sets of minima, and we report measured values on the mill certificate.

Heat treatment

State the delivery condition on the purchase order. Annealed and normalized-and-tempered material machine very differently, and getting the wrong one causes arguments at incoming inspection. Where the drawing calls for it, liquid quenching and tempering can be agreed between purchaser and manufacturer.

Equivalent grades and cross-reference

F9 compared with F5, F11, F22 and F91

Creep strength is what separates F9 from F91 in practice. F91 adds vanadium, niobium and controlled nitrogen to a lower-carbon base. Those form fine carbonitrides that roughly double allowable stress at 550 to 600 °C. The price is a much tighter heat treatment window and strict control of post-weld heat treatment. Where the design case is set by creep, F91 usually wins. Where oxidation and sulphidation resistance matter more than creep, F9 does the job for less money and with fewer ways to get the fabrication wrong.

F9 forged products we supply

Every part is forged to order from the customer drawing. We hold no F9 stock shapes.

How we make and test F9 forgings

Process route

• Ingot or billet from electric arc furnace steel with ladle refining and vacuum degassing, supplied with EN 10204 3.1 certification and full chemistry traceability.
• Open-die forging by upsetting and drawing out, with the forging ratio recorded for each piece.
• Radial-axial ring rolling for seamless rings.
• Heat treatment in house: annealing, or normalizing and tempering, with calibrated furnace charts supplied.
• Rough machining, or finish machining to drawing tolerance.

Inspection and documentation

• Chemical analysis by optical emission spectrometry. Positive material identification on request.
• Tensile testing to ASTM A370, Brinell hardness, and Charpy V-notch impact where specified.
• Ultrasonic examination to ASTM A388 / ASME SA-388. Magnetic particle to ASTM E709 or liquid penetrant to ASTM E165.
• Dimensional report against the customer drawing.
• Mill test certificate to EN 10204 3.1, or 3.2 with third-party endorsement.
• Third-party inspection by TUV, SGS, BV, Lloyd's Register or the customer's own inspector, arranged on request.

Where F9 forgings are used

• Oil refining. Catalytic reformer, hydrocracker and hydrotreater internals, exchanger tubesheets and channel covers, transfer line components in hydrogen and hot sulphidic service.
• Petrochemical. Cracking furnace headers, high-temperature valve bodies and flanges.
• Power generation. Boiler headers, steam piping components and valve parts in subcritical and supercritical units.
• Pressure vessels. Shells, heads, nozzle necks and girth flanges for elevated-temperature service.

How to order F9 forgings

Send the points below and a quotation with weight, price and lead time normally comes back within one working day.

• Specification and grade: ASTM A182 F9, ASTM A336 F9 or the ASME equivalent, with the edition year if your project fixes one.
• Drawing in PDF, DWG or STEP, or finished dimensions with tolerances.
• Rough forged, rough machined or finish machined.
• Delivery condition: annealed, or normalized and tempered.
• Quantity and required delivery date.
• NDT scope and acceptance class.
• Certificate level, EN 10204 3.1 or 3.2, and any third-party inspection.
• Marking, packing and destination port.

Email an enquiry +86 189 2135 9659

Questions about F9

About the manufacturer

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, part of the forging cluster on the south bank of the Yangtze, close to Shanghai and Zhangjiagang ports. We forge carbon steel, alloy steel, tool steel, stainless steel and nickel alloys to customer drawings for pressure vessel, refinery, petrochemical, power and general engineering work.

Related grades we forge

Data on this page is taken from ASTM A182 / A182M, ASTM A336 / A336M and ASTM A335 / A335M. Standards are revised periodically, so confirm values against the edition named in your purchase order before using them for design. Published by Jiangyin Jiangnan Metal Co., Ltd. Last reviewed 14 September 2026.