Steel Y45MnV · supply condition · default condition
Steel Y45MnV-HR
Properties of the HR condition, compared with the other Y45MnV tempers.
Standard stock condition: strength comes from V microalloying during air cooling, so parts can be machined straight from bar.
What is Y45MnV-HR?
Y45MnV-HR is Y45MnV supplied in the HR condition — standard stock condition: strength comes from V microalloying during air cooling, so parts can be machined straight from bar. Y45MnV-HR has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). Y45MnV-HR 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).
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 83% of steel grades
- Difficult to weld — 22/100, worse than 81% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
Y45MnV-HR properties
Typical room-temperature values for Y45MnV-HR — 11 properties are specific to this condition; the rest are grade-level values shared by every Y45MnV temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
Y45MnV-HR 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).
Mechanical16
Y45MnV-HR has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Y45MnV-HR is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Y45MnV-HR conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 87% of steel grades.
Sustainability4
Producing a kilogram of Y45MnV-HR takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
Y45MnV-HR's machinability is good (62/100, better than 89% of steel grades); weldability poor (22/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Y45MnV tempers and conditions
Y45MnV is also supplied in 6 other conditions. The full side-by-side table is on the Y45MnV overview.
- HRDefaultStandard stock condition: strength comes from V microalloying during air cooling, so parts can be machined straight from bar.560 MPa yield · 25 HRC
- QT-32-38HRCHigher-strength shaft condition where load capacity outweighs machining cost and impact demands are moderate.930 MPa yield · 35 HRC
- CDChoose for close-tolerance bright bar feeding automatic lathes where straightness and surface finish matter.780 MPa yield · 30 HRC
- QT-25-30HRCGeneral-purpose tempered condition when better toughness and property uniformity than the as-rolled bar is required.720 MPa yield · 28 HRC
- NUsed to homogenise forged blanks and give a uniform ferrite–pearlite structure before finish machining.510 MPa yield · 21 HRC
- APick when maximum machinability or cold-working ability is needed before a later hardening operation.390 MPa yield · 190 HB
Working with Y45MnV-HR
Is Y45MnV easy to machine?
Turns and drills well on automatics thanks to MnS chip breakers; use rigid setups, coated carbide at 120–200 m/min and avoid dwelling, since work-hardened skin on cold-drawn bar dulls edges.
Can Y45MnV be welded?
Not recommended for structural welds — high carbon plus 0.04–0.08 % S gives hot cracking and hard HAZ; if unavoidable preheat 250–300 °C, use low-hydrogen consumables and post-weld temper.
Can Y45MnV be formed, bent or molded?
Hot forge at 1150–850 °C followed by controlled air cooling to develop the non-quenched strength; cold bending or heading is poor because sulfide stringers open transverse cracks.
What surface finishes work on Y45MnV?
Requires protective coating — phosphate + oil, zinc or Mn phosphate, black oxide, or hard chrome on journals; polishing is limited by sulfide pull-out so avoid decorative mirror finishes.
Y45MnV 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 | 0.42 – 0.5 | 0.46 |
| Sisome mill practices run 0.30–0.60 for solid-solution strengthening | 0.17 – 0.37 | 0.27 |
| Mncombines with S to form machinable MnS | 1 – 1.4 | 1.2 |
| VV(C,N) precipitation strengthening on air cooling | 0.06 – 0.13 | 0.1 |
| Sintentional, free-cutting addition | 0.04 – 0.08 | 0.06 |
| P | ≤ 0.06 | 0.03 |
| Crresidual | ≤ 0.3 | — |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.25 | — |
| Fe | balance | — |
Y45MnV-HR — frequently asked
What is Y45MnV-HR used for?
Y45MnV-HR is typically used for crankshafts, high-load shafts and automotive components. In short: strongest grade in family; microalloyed, no quench needed; 860 MPa with 14 % elongation.
What is the yield strength of Y45MnV-HR?
Y45MnV-HR has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is Y45MnV-HR easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Turns and drills well on automatics thanks to MnS chip breakers; use rigid setups, coated carbide at 120–200 m/min and avoid dwelling, since work-hardened skin on cold-drawn bar dulls edges.
Can Y45MnV-HR be welded?
Not readily — weldability is rated poor (22/100). Not recommended for structural welds — high carbon plus 0.04–0.08 % S gives hot cracking and hard HAZ; if unavoidable preheat 250–300 °C, use low-hydrogen consumables and post-weld temper.
What surface finishes work on Y45MnV-HR?
Requires protective coating — phosphate + oil, zinc or Mn phosphate, black oxide, or hard chrome on journals; polishing is limited by sulfide pull-out so avoid decorative mirror finishes.
Can Y45MnV-HR be formed, bent or molded?
Hot forge at 1150–850 °C followed by controlled air cooling to develop the non-quenched strength; cold bending or heading is poor because sulfide stringers open transverse cracks.
What is the maximum service temperature of Y45MnV-HR?
Y45MnV-HR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Y45MnV-HR and Y45MnV-CD?
HR is the default condition — standard stock condition: strength comes from V microalloying during air cooling, so parts can be machined straight from bar. CD: choose for close-tolerance bright bar feeding automatic lathes where straightness and surface finish matter. Yield strength is 560 MPa in HR versus 780 MPa in CD.
Sources
- GB/T 8731 (Free-cutting structural steels) (2008)
- GB/T 15712 (Non-quenched and tempered structural steels) — SAC (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16: Machining (free-machining steel ratings) — ASM International (1989)
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.