Steel 32CrAlMo7-10 +QT+NIT (+QT + gas/plasma nitrided)
Finish state
EN 32CrAlMo7-10
Final in-service condition: 0.2–0.6 mm diffusion case at 900–1050 HV1 for maximum wear and fatigue performance on gears, spindles and screws.
Values for the +QT+NIT condition
Other 32CrAlMo7-10 tempers and conditions
32CrAlMo7-10 is listed in 6 conditions; see the grade overview at 32CrAlMo7-10.
- +A
- +N
- +QT160-250
- +QT100-160
- +QT
- +QT+NIT
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for bar/forging stock that will be rough-machined and then quenched and tempered by the user. | 450 | 720 | 20 | 225 HB | — |
Normalized | Grain-refining condition after forging, usually an intermediate step before final quench and temper. | 560 | 880 | 15 | 27 HRC | 7 % IACS |
+QT | Large-diameter forged bar and rolls; lowest guaranteed core strength band of the grade. | 650 | 850 | 14 | 27 HRC | 7 % IACS |
+QT | Same heat treatment on heavier bar/forging where reduced cooling rate lowers the guaranteed strength band. | 700 | 900 | 13 | 29 HRC | 7 % IACS |
+QTDefault Quenched and tempered | Standard supply and pre-nitriding condition: tough tempered-martensite core with high enough temper temperature (≥ 580 °C) to stay dimensionally stable during nitriding. | 760 | 950 | 12 | 31 HRC | — |
+QT+NITThis page +QT + gas/plasma nitrided | Final in-service condition: 0.2–0.6 mm diffusion case at 900–1050 HV1 for maximum wear and fatigue performance on gears, spindles and screws. | 760 | 950 | 11 | 68 HRC | — |
What is 32CrAlMo7-10 +QT+NIT?
32CrAlMo7-10 +QT+NIT is 32CrAlMo7-10 supplied in the +QT+NIT condition — final in-service condition: 0.2–0.6 mm diffusion case at 900–1050 HV1 for maximum wear and fatigue performance on gears, spindles and screws. 32CrAlMo7-10 +QT+NIT has a yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi). 32CrAlMo7-10 +QT+NIT has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,420°C (2,588 °F). +QT is the default condition FabDigit quotes; +QT+NIT is available on request or by drawing note.
Advantages
- Good corrosion resistance — 25/100, better than 92% of steel grades
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 760 MPa (110 ksi), better than 85% of steel grades
Limitations
- Difficult to machine — 12/100, worse than 99% of steel grades
- Limited ductility — 11%, worse than 89% of steel grades
- Difficult to weld — 18/100, worse than 87% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
- Limited formability — 22/100, worse than 76% of steel grades
32CrAlMo7-10 +QT+NIT properties
Typical room-temperature values for 32CrAlMo7-10 +QT+NIT; 12 are specific to this condition. Other listed values are 32CrAlMo7-10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
32CrAlMo7-10 +QT+NIT has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
32CrAlMo7-10 +QT+NIT has a yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
32CrAlMo7-10 +QT+NIT is rated for continuous service to 500°C (932 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
32CrAlMo7-10 +QT+NIT conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of 32CrAlMo7-10 +QT+NIT takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
32CrAlMo7-10 +QT+NIT's machinability is not recommended (12/100, worse than 99% of steel grades); weldability poor (18/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 32CrAlMo7-10 +QT+NIT
Is 32CrAlMo7-10 easy to machine?
Rough machine soft-annealed, finish in the +QT condition with carbide at moderate speed leaving 0.05–0.15 mm grinding stock; after nitriding only grinding/lapping is possible.
Can 32CrAlMo7-10 be welded?
Effectively non-weldable for structural joints — high Al, Cr and C cause cracking; if unavoidable, preheat 300–350 °C, matching filler and immediate stress relief, and never weld a nitrided surface.
Can 32CrAlMo7-10 be formed, bent or molded?
Hot forge 1100→850 °C with slow cooling and normalising; cold forming is not practical at Q&T strength levels.
What surface finishes work on 32CrAlMo7-10?
Stress-relieve before nitriding, mask threads/holes, then gas or plasma nitride at 500–530 °C; post-oxidation, phosphating or black oxide add mild corrosion protection — do not hard chrome plate over a nitrided compound layer without stripping it.
32CrAlMo7-10 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 | 0.28 – 0.35 | 0.32 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | — |
| Smax; lower for high-cleanliness variants | ≤ 0.04 | — |
| Cr | 1.5 – 1.8 | 1.65 |
| Mo | 0.25 – 0.4 | 0.32 |
| Alnitride former giving the very hard case | 0.8 – 1.2 | 1 |
| Fe | balance | — |
32CrAlMo7-10 +QT+NIT — frequently asked
What is 32CrAlMo7-10 +QT+NIT used for?
32CrAlMo7-10 +QT+NIT is typically used for precision gears, machine tool spindles, wear-resistant shafts and cylinder liners. In short: hardest nitrided case; tough core, hard surface; not weldable.
What is the yield strength of 32CrAlMo7-10 +QT+NIT?
32CrAlMo7-10 +QT+NIT has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 32CrAlMo7-10 +QT+NIT easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Rough machine soft-annealed, finish in the +QT condition with carbide at moderate speed leaving 0.05–0.15 mm grinding stock; after nitriding only grinding/lapping is possible.
Can 32CrAlMo7-10 +QT+NIT be welded?
Not readily — weldability is rated poor (18/100). Effectively non-weldable for structural joints — high Al, Cr and C cause cracking; if unavoidable, preheat 300–350 °C, matching filler and immediate stress relief, and never weld a nitrided surface.
What surface finishes work on 32CrAlMo7-10 +QT+NIT?
Stress-relieve before nitriding, mask threads/holes, then gas or plasma nitride at 500–530 °C; post-oxidation, phosphating or black oxide add mild corrosion protection — do not hard chrome plate over a nitrided compound layer without stripping it.
Can 32CrAlMo7-10 +QT+NIT be formed, bent or molded?
Hot forge 1100→850 °C with slow cooling and normalising; cold forming is not practical at Q&T strength levels.
What is the maximum service temperature of 32CrAlMo7-10 +QT+NIT?
32CrAlMo7-10 +QT+NIT is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10085 — Nitriding steels: technical delivery conditions — CEN (2001)
- GB/T 3077 (38CrMoAl comparison grade) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating / Nitriding — ASM International (2013)
- Nitriding steel 1.8505 / 32CrAlMo7-10 bar datasheet — European special-steel producers (Böhler, Ovako, Lucchini class data) (2022)
- 38CrMoAl — Mysteel / 1688 (2026)
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.