Steel 54SiCrV6 +CH
Heat-treated state
EN 54SiCrV6
+CH = supplied with guaranteed core hardenability / core hardness band
Order when the finished part must meet a specified through-thickness (core) hardness after quench and temper, e.g. thick torsion bars and heavy leaf sections.
Values for the +CH condition
Other 54SiCrV6 tempers and conditions
54SiCrV6 is listed in 8 conditions; see the grade overview at 54SiCrV6.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Softest, most ductile delivery state — pick for heavy cold upsetting, deep drawing or cold extrusion before hardening. | 420 | 700 | 20 | 210 HB | — |
Treated for high shearability | Pick when bar/coil must be cold sheared or cropped to blanks without cracking prior to hardening. | 440 | 750 | 18 | 19 HRC | 7 % IACS |
Annealed | Choose for cold forming, machining or coiling of bar/flat before final hardening. | 460 | 780 | 16 | 230 HB | — |
Cold drawn | Pick for close dimensional tolerance and bright surface on bar destined for machining and subsequent hardening. | 850 | 1,000 | 8 | 31 HRC | 6.8 % IACS |
+CHThis page Supplied with guaranteed core hardenability / core hardness band | Order when the finished part must meet a specified through-thickness (core) hardness after quench and temper, e.g. thick torsion bars and heavy leaf sections. | 1,350 | 1,500 | 9 | 44 HRC | 6.2 % IACS |
+QTDefault Quenched and tempered | Standard service condition for coil, leaf and torsion springs — highest usable strength/fatigue combination. | 1,650 | 1,800 | 7 | 50 HRC | — |
Hardened | As-quenched state only — maximum hardness but brittle; must be tempered before service. | 1,800 | 2,200 | 1 | 60 HRC | — |
Oil hardened and tempered spring wire (VDSiCr, EN 10270-2) | Pick for high-duty valve springs and small coil springs supplied ready-to-coil at full strength with clean, decarb-free surface. | 1,800 | 2,000 | 5 | 54 HRC | 6 % IACS |
What is 54SiCrV6 +CH?
54SiCrV6 +CH is 54SiCrV6 heat treated to +CH — order when the finished part must meet a specified through-thickness (core) hardness after quench and temper, e.g. thick torsion bars and heavy leaf sections. 54SiCrV6 +CH has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 9% and the elastic modulus is 206 GPa (29.9 Msi). 54SiCrV6 +CH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). +QT is the default condition FabDigit quotes; +CH is available on request or by drawing note.
Advantages
- High strength — 1,350 MPa (196 ksi), better than 95% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 9%, worse than 93% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
54SiCrV6 +CH properties
Typical room-temperature values for 54SiCrV6 +CH; 22 are specific to this condition. Other listed values are 54SiCrV6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
54SiCrV6 +CH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
54SiCrV6 +CH has a yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 9% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
54SiCrV6 +CH is rated for continuous service to 250°C (482 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
54SiCrV6 +CH conducts electricity at 6.2 % IACS, worse than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 54SiCrV6 +CH takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
54SiCrV6 +CH's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (15/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 54SiCrV6 +CH
Is 54SiCrV6 easy to machine?
Machine in +A/+AC condition (carbide or coated HSS, 60–120 m/min); after Q&T at ~50 HRC only grinding or CBN hard-turning is practical.
Can 54SiCrV6 be welded?
Essentially unweldable in service condition (CE ≈ 0.85); if unavoidable, preheat 300–400 °C, low-hydrogen consumables and immediate post-weld temper — expect loss of spring properties.
Can 54SiCrV6 be formed, bent or molded?
Hot form 900–1050 °C or cold coil in annealed state; austenitize ~860–880 °C, oil quench, temper 400–480 °C for 46–52 HRC, then stress relieve after coiling.
What surface finishes work on 54SiCrV6?
Shot peen (and preferably stress-peen) to maximize fatigue life; protect with phosphate + epoxy powder or zinc-flake; avoid electroplating or bake ≥4 h at 200 °C to prevent hydrogen embrittlement; control surface decarburization to spec.
54SiCrV6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.51 – 0.59 | 0.55 |
| Siraises elastic limit and relaxation resistance | 1.2 – 1.6 | 1.4 |
| Mn | 0.5 – 0.8 | 0.65 |
| Crhardenability | 0.5 – 0.8 | 0.65 |
| Vgrain refinement, temper resistance | 0.1 – 0.2 | 0.15 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
54SiCrV6 +CH — frequently asked
What is 54SiCrV6 +CH used for?
54SiCrV6 +CH is typically used for automotive coil springs, torsion bars, railway suspension springs and high-fatigue mechanical springs. In short: valve-spring quality Si-Cr-V; 1650 MPa yield at 50 HRC; effectively unweldable.
What is the yield strength of 54SiCrV6 +CH?
54SiCrV6 +CH has a typical yield strength of 1,350 MPa (196 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 54SiCrV6 +CH easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine in +A/+AC condition (carbide or coated HSS, 60–120 m/min); after Q&T at ~50 HRC only grinding or CBN hard-turning is practical.
Can 54SiCrV6 +CH be welded?
Not readily — weldability is rated poor (15/100). Essentially unweldable in service condition (CE ≈ 0.85); if unavoidable, preheat 300–400 °C, low-hydrogen consumables and immediate post-weld temper — expect loss of spring properties.
What surface finishes work on 54SiCrV6 +CH?
Shot peen (and preferably stress-peen) to maximize fatigue life; protect with phosphate + epoxy powder or zinc-flake; avoid electroplating or bake ≥4 h at 200 °C to prevent hydrogen embrittlement; control surface decarburization to spec.
Can 54SiCrV6 +CH be formed, bent or molded?
Hot form 900–1050 °C or cold coil in annealed state; austenitize ~860–880 °C, oil quench, temper 400–480 °C for 46–52 HRC, then stress relieve after coiling.
What is the maximum service temperature of 54SiCrV6 +CH?
54SiCrV6 +CH is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10089 — Hot rolled steels for quenched and tempered springs — CEN (2002)
- EN 10270-2 — Steel wire for mechanical springs: oil hardened and tempered spring steel wire (VDSiCr) — CEN (2011)
- EN 10083-1 — Steels for quenching and tempering: general technical delivery conditions (delivery states +A, +AC, +S, +QT) — CEN (2006)
- GB/T 1222 — (55SiCrA / 55SiCrVA) — SAC (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (spring steels) — ASM International (1990)
- EN 13906-1 — Cylindrical helical springs, design and calculation — CEN (2013)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.