21CrMoNiV4-7 (1.6981) forgings: rotor shafts, discs, rings and bars

Data sheet maintained by the Jiangyin Jiangnan Metal engineering department. Last reviewed 10 September 2026.

What 21CrMoNiV4-7 is

21CrMoNiV4-7 is a low-alloy engineering steel carrying about 1 % chromium, 0.7 % molybdenum, a controlled nickel addition and 0.25 to 0.35 % vanadium. The vanadium forms fine carbides during tempering. Those carbides are what keep proof strength up at temperature and give the grade its creep resistance. Carbon stays between 0.17 % and 0.25 %, low enough that the steel remains weldable with correct preheat and post-weld heat treatment.

Alloy content is modest next to a 12 % chromium turbine steel such as X22CrMoV12-1, so the grade hardens through in heavy sections and machines without trouble. Turbine builders specify it for large rotating and pressure-retaining parts where a leaner quenched and tempered steel such as 42CrMo4 would not hold up at service temperature.

We forge the grade from ingot rather than cutting it out of stock bar. Forging reduction ratio, grain flow direction and test-piece location are set to match your drawing and specification.

Chemical composition of 21CrMoNiV4-7

Balance iron. Aluminium content of the cast is reported on the certificate. Where a customer specification is tighter than the table above, for example a lower phosphorus and sulphur ceiling for rotor duty, we order the heat to the tighter limits and report ladle and product analysis separately.

Heat treatment of 21CrMoNiV4-7

Soak times depend on ruling section. We record every furnace cycle and issue the time and temperature chart with the forging.

Mechanical properties and how they are agreed

21CrMoNiV4-7 has no single fixed property table. Proof strength, tensile strength, elongation, reduction of area and notched-bar impact energy are agreed part by part, since they depend on ruling section, test-piece position and the service temperature the turbine builder is designing to. Most specifications call up both room-temperature and elevated-temperature values.

Send us the property table from your drawing or specification. We confirm in writing before the order whether those values are achievable in the section you need, then prove them on the finished forging with witnessed tests. Where the specification requires it, sacrificial test prolongations are forged integrally with the part.

Forged shapes we produce in 21CrMoNiV4-7

All of the following are forged to drawing in 21CrMoNiV4-7 (1.6981). Send geometry and quantity and we will price it.

Size and weight capability

Inspection, testing and certification

We control the whole route in house: ingot selection, forging, heat treatment, machining and final inspection. Nothing leaves the works without a complete document package.

• Material certificate to EN 10204 3.1, or 3.2 counter-signed by a nominated third party such as SGS, BV, TÜV or Lloyd's Register.
• Ultrasonic testing to EN 10228-3, with inspection class and acceptance level set by part geometry and your specification. Full volumetric coverage is available.
• Surface NDT by magnetic particle inspection to EN 10228-1 or dye penetrant to EN 10228-2.
• Chemical analysis of both ladle and product samples by spectrometer.
• Mechanical testing per the table above, with test-piece location recorded on the certificate.
• Heat treatment records, meaning furnace charts for every quench and temper cycle.
• Dimensional report against the drawing, with marking, hard stamping and heat-number traceability.

Third-party witness inspection, customer source inspection and pre-shipment audits are all accommodated. Send the inspection and test plan you work to and we return it marked up with our hold and witness points.

Comparable and related turbine grades

Buyers looking at 21CrMoNiV4-7 usually price these grades at the same time. All of them are forged at the same works, so one enquiry can cover a mixed bill of materials.

• 30CrMoNiV5-11 (1.6946), a higher carbon CrMoNiV turbine steel chosen when more strength is needed in a similar section.
• 21CrMoV5-7 (1.7709) and 21CrMoV5-11 (1.8070), creep-resistant bolting and rotor steels without the nickel addition.
• X22CrMoV12-1 (1.4923), a 12 % chromium martensitic steel for higher steam temperatures and better oxidation resistance.
• 20CrMoNiWV8-8, a tungsten-bearing rotor steel for high-temperature stages.
• 42CrMo4, AISI 4140 and 34CrMo4, general quenched and tempered grades for parts that do not need hot strength.
• Inconel 718, Nimonic 80A and Inconel 706, nickel-base alloys for the hottest turbine sections.

How to get a 21CrMoNiV4-7 quotation

1. Send the drawing or the dimensions. A PDF, a STEP file or a dimensioned sketch is enough to start. Include grade, quantity, delivery condition and any customer specification number.
2. We review and confirm feasibility. Our engineers check section size against achievable properties, confirm the test plan and flag anything in the specification that needs clarifying, normally within one working day.
3. You receive a firm price and lead time. The quotation states ingot route, forging reduction, heat treatment, machining allowance, NDT scope, certificate type and packing.

Frequently asked questions about 21CrMoNiV4-7

Standards and references

• EN 10204, types of inspection document for metallic products.
• EN 10228-1, -2 and -3, non-destructive testing of steel forgings by magnetic particle, penetrant and ultrasonic methods.
• EN 10269, steels and nickel alloys for fasteners with specified elevated or low temperature properties, commonly invoked for turbine bolting.
• ISO 6892-1 and ISO 6892-2, tensile testing of metallic materials at ambient and elevated temperature.
• Independent grade data for 1.6981 is published by Stahlhandel Gröditz and Pauly Stahlhandel.