Steel GCr4-N (Normalized)
Heat-treated state
GB GCr4
Used to break up network carbides or banded structure in large forged rings before spheroidizing.
Values for the N condition
Other GCr4 tempers and conditions
GCr4 is listed in 7 conditions; see the grade overview at GCr4.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard delivery condition for bar, tube and ring blanks — soft, uniform spheroidized carbides, ready for turning and subsequent hardening. | 390 | 640 | 21 | 190 HB | — |
Hot rolled | Mill as-rolled bar or tube blank; must be spheroidize annealed before machining or cold forming. | 480 | 850 | 12 | 25 HRC | 7 % IACS |
NThis page Normalized | Used to break up network carbides or banded structure in large forged rings before spheroidizing. | 520 | 950 | 10 | 30 HRC | 7 % IACS |
Cold drawn | Cold-drawn bar or bearing tube for close size tolerance and better surface before ring parting. | 600 | 780 | 10 | 20 HRC | 7 % IACS |
Q&T + 200–250 °C stabilizing temper | Higher tempering for bearings running warm (up to ~180–200 °C) where dimensional stability outranks peak hardness. | 1,700 | 1,950 | 1 | 58 HRC | 5.4 % IACS |
IH 58–62 HRC | The design condition for GCr4: hard, compressively stressed raceway layer over a tough unhardened core — chosen for large railway and wind-gear bearing rings. | — | 2,100 | 1 | 60 HRC | 40 W/m·K |
Q&T 60–64 HRC | Through-hardened small rings and rollers; limited to thin sections because GCr4 is deliberately low in hardenability. | — | 2,250 | 0.5 | 62 HRC | — |
What is GCr4-N?
GCr4-N is GCr4 heat treated to N — used to break up network carbides or banded structure in large forged rings before spheroidizing. GCr4-N has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 67% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). GCr4-N has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; N is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 85/100, better than 99% of steel grades
Limitations
- Difficult to machine — 25/100, worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
GCr4-N properties
Typical room-temperature values for GCr4-N; 22 are specific to this condition. Other listed values are GCr4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
GCr4-N has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
GCr4-N has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 67% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
GCr4-N 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 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
GCr4-N conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of GCr4-N takes about 31 MJ of energy and emits 2.3 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
GCr4-N's machinability is poor (25/100, worse than 93% 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 GCr4-N
Is GCr4 easy to machine?
Turn and drill only in the spheroidize-annealed state (≤207 HB) with coated carbide, low speed and rigid setup; after hardening use CBN hard turning or grinding.
Can GCr4 be welded?
Effectively unweldable at ~1 %C — if repair is unavoidable, preheat 300–400 °C, use low-hydrogen filler and immediately post-weld temper.
Can GCr4 be formed, bent or molded?
Ring blanks are hot forged/ring-rolled at 1050–1120 °C then slowly cooled and spheroidize annealed (780–800 °C soak, slow cool to ~700 °C) to avoid network carbides.
What surface finishes work on GCr4?
Raceways are hard-turned then ground and superfinished; corrosion protection by oiling, manganese phosphate or black oxide — no anodizing possible.
GCr4 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 | 0.95 – 1.05 | 1 |
| Si | 0.15 – 0.3 | 0.23 |
| Mn | 0.15 – 0.3 | 0.25 |
| Crdeliberately low for shallow hardening | 0.35 – 0.5 | 0.43 |
| Moresidual | ≤ 0.08 | — |
| Niresidual | ≤ 0.25 | — |
| Curesidual; Ni+Cu ≤ 0.50 | ≤ 0.2 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| O≤12 ppm for high-grade bearing quality | ≤ 0 | — |
| Ti | ≤ 0.01 | — |
| Fe | balance | — |
GCr4-N — frequently asked
What is GCr4-N used for?
GCr4-N is typically used for large induction-hardened bearing rings, slewing bearing raceways, crane and excavator slew rings, turntable bearing inner and outer rings, heavy thrust washers and locally hardened shaft journals. In short: induction-hardening bearing steel; leaner Cr than 100Cr6; tough core, hard raceway.
What is the yield strength of GCr4-N?
GCr4-N has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is GCr4-N easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of steel grades). Turn and drill only in the spheroidize-annealed state (≤207 HB) with coated carbide, low speed and rigid setup; after hardening use CBN hard turning or grinding.
Can GCr4-N be welded?
Not readily — weldability is rated poor (15/100). Effectively unweldable at ~1 %C — if repair is unavoidable, preheat 300–400 °C, use low-hydrogen filler and immediately post-weld temper.
What surface finishes work on GCr4-N?
Raceways are hard-turned then ground and superfinished; corrosion protection by oiling, manganese phosphate or black oxide — no anodizing possible.
Can GCr4-N be formed, bent or molded?
Ring blanks are hot forged/ring-rolled at 1050–1120 °C then slowly cooled and spheroidize annealed (780–800 °C soak, slow cool to ~700 °C) to avoid network carbides.
What is the maximum service temperature of GCr4-N?
GCr4-N 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.
What is the difference between GCr4-A and GCr4-CD?
A is the default condition — standard delivery condition for bar, tube and ring blanks — soft, uniform spheroidized carbides, ready for turning and subsequent hardening. CD: cold-drawn bar or bearing tube for close size tolerance and better surface before ring parting. Yield strength is 390 MPa in A versus 600 MPa in CD.
Sources
- ГОСТ 801 Сталь подшипниковая (ШХ4) — Gosstandart (1978)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (Bearing Steels) — ASM International (1990)
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.