14CrMo4-5 forgings

What 14CrMo4-5 is

14CrMo4-5 is a low-carbon chromium-molybdenum steel with nominally 1 % chromium and 0.5 % molybdenum. Europe specifies it as 13CrMo4-5, material number 1.7335. It is a creep-resistant boiler and pressure-vessel grade. It is not a through-hardening structural steel.

Chromium gives oxidation resistance and resistance to high-temperature hydrogen attack. Molybdenum raises creep-rupture strength and holds back temper embrittlement. The combination keeps useful strength at temperatures where carbon and carbon-manganese steels have already softened. Superheater headers, refinery reactors and steam-line fittings have used this grade for a long time.

Carbon is held low, so the steel welds and machines without difficulty. Normal supply condition is normalised and tempered, not quenched and tempered. Four European standards cover it, depending on product form:

• EN 10222-2, steel forgings for pressure purposes. This governs our forged rings, discs, shafts and hollow forgings.
• EN 10028-2, flat products for pressure purposes. The composition and room-temperature property tables below are quoted from it.
• EN 10216-2, seamless tubes for pressure purposes.
• EN 10273, hot-rolled weldable bars for pressure purposes.

We work to whichever of these the drawing calls up. Projects that need both EN and ASTM acceptance can have both cross-certified on one certificate.

Designation and equivalents

14CrMo4-5 and 13CrMo4-5 are the same steel, EN 1.7335. The 14 spelling comes from Italian UNI practice and from the ISO designation 14CrMo45. The 13 spelling is the current European name in EN 10028-2 and EN 10222-2. Either one on a purchase order describes the same material.

Buyers run into two mix-ups with this grade. Both are worth checking before an order goes out.

The second mix-up is with ASTM. A387 Grade 11 and A182 F11 are nominally 1.25 %Cr, 0.5 %Mo. They sit close to 14CrMo4-5 but carry more chromium. Grade 12, F12 and P12 are the 1Cr, 0.5Mo counterparts and are the correct cross-reference.

One other near neighbour: 10CrMo9-10, material number 1.7380, is the 2.25 %Cr, 1 %Mo grade for service hotter than 14CrMo4-5 can carry.

Chemical composition

EN 10028-2 specifies 0.08 to 0.18 % carbon, 0.70 to 1.15 % chromium and 0.40 to 0.60 % molybdenum, with manganese 0.40 to 1.00 %, silicon to 0.35 %, phosphorus to 0.025 %, sulphur to 0.010 %, nitrogen to 0.012 % and copper to 0.30 %. Balance iron.

EN 10216-2 narrows two of these ranges for seamless tube: carbon 0.10 to 0.17 % and manganese 0.40 to 0.70 %. Hollow forgings ordered as tube-equivalent stock are melted to the tube window, so one billet satisfies both specifications.

Sulphur capped at 0.010 % is tight for a general-purpose alloy steel. That cap is what keeps through-thickness ductility usable in tubesheets loaded in the short-transverse direction. Nitrogen is capped because free nitrogen promotes strain ageing, so the steel is aluminium-killed and vacuum degassed.

Mechanical properties

Normalised and tempered, 14CrMo4-5 gives 450 to 600 MPa tensile strength and 300 MPa minimum yield in sections to 16 mm. Minimum elongation is 22 % longitudinal. Charpy KV at +20 °C is 40 J longitudinal. Both strength figures fall as ruling section increases.

Physical properties

Density is about 7.85 g/cm³, Young's modulus about 212 GPa at room temperature and thermal conductivity about 42 W/m·K. These are typical low-alloy ferritic values.

Heat treatment and forging route

Standard route is normalise at 910 to 940 °C with air cooling, then temper at 650 to 720 °C with air cooling. A quench and temper route is available where a project needs higher strength: harden at 890 to 910 °C in water or 900 to 930 °C in oil, then temper in the same 650 to 720 °C window.

1. Forge, 1150 to 1200 °C Ingot or bloom is soaked, upset and drawn on the open-die press. Minimum 3:1 reduction ratio breaks down the as-cast structure. Forging stops above 850 °C to stay out of the two-phase region. Cool in still air.
2. Normalise, 910 to 940 °C Reheat above the upper critical temperature, soak in proportion to ruling section, cool in still air. This refines grain size and gives the uniform ferrite-bainite structure the property tables assume.
3. Temper, 650 to 720 °C Air cool. Temperature within the window is set from ruling section and the property targets on the order.
4. Stress relieve, 660 to 710 °C Applied when heavy machining, weld overlay or cladding follows. Held below the tempering temperature so the tempered properties stay intact. Air cool.
5. Test and certify Coupons are cut after final heat treatment and carry the same thermal history as the forging. Tensile, Charpy, hardness and ultrasonic results go on the EN 10204 certificate.

Welding 14CrMo4-5

14CrMo4-5 welds with matching Cr-Mo consumables: ER80S-B2L wire for the TIG root, E8018-B2 electrodes for fill and cap. It is a hardenable Cr-Mo steel, so preheat and post-weld heat treatment apply on all but the thinnest sections.

• Preheat and interpass: 150 to 250 °C, rising with thickness, carbon equivalent and restraint.
• Post-weld heat treatment: 650 to 700 °C, held below the tempering temperature of the parent forging.
• Route without PWHT: ER80S-B2L for the root with E309Mo-16 for fill and cap is sometimes used where PWHT is impractical. It changes the creep behaviour of the joint, so agree it with the design authority first.
• Main risk: hydrogen-induced cracking. Keep consumables dry, control interpass temperature, and delay NDT per the governing code.

Qualify the procedure against ASME IX, EN ISO 15614 or the customer specification. The figures above are starting points for procedure qualification.

Forging capability in 14CrMo4-5

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging works in Jiangyin, Jiangsu, China. 14CrMo4-5 / 1.7335 forgings run from 20 kg to 30 tonnes single-piece weight. Seamless rolled rings go to 4,000 mm outside diameter, discs and tubesheets to 3,000 mm diameter.

Steel comes from electric-arc furnace melting with ladle refining and vacuum degassing. That is what holds sulphur under 0.010 % and keeps hydrogen low enough to avoid flaking in heavy sections.

Forging, heat treatment, rough machining, non-destructive testing and mechanical testing all run on site, so one works order covers the part from billet through to certificate. Delivery condition options are as-forged, rough machined with allowance, proof machined, or finish machined to drawing. Weld overlay and cladding of tubesheets in stainless, Inconel 625 or Incoloy 825 runs through regular subcontract partners.

Shapes we forge in 14CrMo4-5

Every item below has run in Cr-Mo grades on our presses and ring mill. Send a drawing and we will tell you the closest existing tooling.

Where 14CrMo4-5 is used

14CrMo4-5 suits pressure-retaining parts running hot enough that carbon steel loses strength, but not hot enough to justify 2.25Cr-1Mo. In practice that is the 400 to 530 °C band in power generation, refining and petrochemicals.

14CrMo4-5 against neighbouring grades

16Mo3 covers service below about 500 °C where chromium is not needed. 14CrMo4-5 covers to about 530 °C. 10CrMo9-10 covers above that. 42CrMo4 is a quenched and tempered structural steel with no creep or pressure-purpose qualification, so it does not substitute.

Testing and certification

Every 14CrMo4-5 forging is released against an EN 10204 3.1 inspection certificate covering heat and product analysis, mechanical test results, the heat-treatment record and the NDT report. EN 10204 3.2 witnessed by a third-party agency is available when specified at order.

Third-party inspection can be arranged at our works. Tell us the inspection level at enquiry stage so the test plan is priced in rather than added later.

How to order

Send a drawing, or a sketch with the ruling dimensions. Without a drawing, these six items are enough for us to quote:

1. Grade and standard. 14CrMo4-5, 13CrMo4-5 or the ASTM equivalent, and which EN or ASTM specification governs.
2. Shape and dimensions, with machining allowance if the part is to be rough machined.
3. Quantity, and whether this is a one-off, a project batch or a repeating annual requirement.
4. Delivery condition. As-forged, rough machined, proof machined or finish machined.
5. Heat treatment condition. Normalised and tempered, or quenched and tempered.
6. Certification and inspection level. EN 10204 3.1, or 3.2 with a named third-party agency.

Quotations go out within 24 hours on working days. Typical lead time is 25 to 45 days from order confirmation, depending on section size and heat-treatment queue, ex-works Jiangyin, shipped through Shanghai or Zhangjiagang. Forgings are packed in seaworthy wooden cases or on steel pallets, with rust preventive applied to machined surfaces.

Frequently asked questions

Data sources and revision

Composition and property values on this page are quoted from EN 10028-2, EN 10222-2 and EN 10216-2. The size envelope, heat-treatment practice and delivery information describe production at our works in Jiangyin. Where customer project data differs from a published table, the mill certificate for that heat governs.

Published 12 April 2019. Last reviewed 8 September 2026 against the current editions of the referenced standards. Maintained by the engineering team at Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China.