Steel AR450 · certified grade
Steel AR450 Q&T-IT
Properties of the Q&T-IT condition, compared with the other AR450 tempers.
Same hardness class but with guaranteed low-temperature Charpy values; pick for cold-climate mining/haul-body structures where impact loading matters.
What is AR450 Q&T-IT?
AR450 Q&T-IT is AR450 in a Q&T-IT certified grade — same hardness class but with guaranteed low-temperature Charpy values; pick for cold-climate mining/haul-body structures where impact loading matters. AR450 Q&T-IT has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). AR450 Q&T-IT 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). Q&T is the default condition FabDigit quotes; Q&T-IT is available on request or by drawing note.
Advantages
- High strength — 1,250 MPa (181 ksi), better than 95% of steel grades
Limitations
- Difficult to machine — 18/100, worse than 98% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 76% of steel grades
AR450 Q&T-IT properties
Typical room-temperature values for AR450 Q&T-IT — 8 properties are specific to this condition; the rest are grade-level values shared by every AR450 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
AR450 Q&T-IT 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
AR450 Q&T-IT has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
AR450 Q&T-IT is rated for continuous service to 250°C (482 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 74% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
AR450 Q&T-IT has an electrical resistivity of 2.5×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of AR450 Q&T-IT takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 30%.
Manufacturability6
AR450 Q&T-IT's machinability is poor (18/100, worse than 98% of steel grades); weldability fair (45/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other AR450 tempers and conditions
AR450 is also supplied in 3 other conditions. The full side-by-side table is on the AR450 overview.
- Q&TDefaultStandard stocked wear plate condition; pick for general abrasion resistance in liners, chutes, buckets and cutting edges.1,250 MPa yield · 46 HRC
- Q&T-ITSame hardness class but with guaranteed low-temperature Charpy values; pick for cold-climate mining/haul-body structures where impact loading matters.1,250 MPa yield · 46 HRC
Working with AR450 Q&T-IT
Is AR450 easy to machine?
Treat as ~45 HRC hardened steel: rigid setup, negative-rake carbide or CBN, low speed/high feed; prefer plasma/laser/waterjet cutting or drilling with carbide, and de-stress after thermal cutting.
Can AR450 be welded?
Weldable with low-hydrogen consumables (undermatching, ~500–700 MPa filler is usual); preheat 100–200 °C depending on thickness and CE, keep interpass below ~225 °C, no PWHT above the tempering temperature.
Can AR450 be formed, bent or molded?
Cold bending possible with min inside radius ≈4–5×t transverse to rolling direction (AR450F allows tighter); hot forming above ~250 °C destroys the hardness.
What surface finishes work on AR450?
Supplied as mill/shot-blasted surface; protect with zinc-rich primer or industrial paint, or overlay/hardface wear faces — not anodizable and rarely polished.
AR450 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 |
|---|---|---|
| Ccarbon equivalent controls preheat | 0.19 – 0.3 | 0.25 |
| Si | 0.15 – 0.7 | 0.35 |
| Mn | 0.8 – 1.7 | 1.3 |
| P | ≤ 0.03 | — |
| S | ≤ 0.01 | — |
| Cr | ≤ 1.2 | 0.6 |
| Nihigher in thick plate for hardenability/toughness | ≤ 1.5 | 0.3 |
| Mo | ≤ 0.6 | 0.25 |
| Bboron treated for through-hardening | ≤ 0.01 | 0 |
| Al | 0.02 – 0.06 | 0.03 |
| Tities up N so boron stays effective | ≤ 0.05 | — |
| Nb+V | ≤ 0.1 | — |
| Fe | balance | — |
AR450 Q&T-IT — frequently asked
What is AR450 Q&T-IT used for?
AR450 Q&T-IT is typically used for mining and quarry liners, dump truck bed floors and sides, bucket wear plates and cutting edges, chutes and hopper linings, crusher and screen plant liners and conveyor skirt and wear strips. In short: workhorse wear-resistant plate.
What is the yield strength of AR450 Q&T-IT?
AR450 Q&T-IT has a typical yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is AR450 Q&T-IT easy to machine?
Not especially — machinability is rated poor (18/100, worse than 98% of steel grades). Treat as ~45 HRC hardened steel: rigid setup, negative-rake carbide or CBN, low speed/high feed; prefer plasma/laser/waterjet cutting or drilling with carbide, and de-stress after thermal cutting.
Can AR450 Q&T-IT be welded?
With care — weldability is rated fair (45/100). Weldable with low-hydrogen consumables (undermatching, ~500–700 MPa filler is usual); preheat 100–200 °C depending on thickness and CE, keep interpass below ~225 °C, no PWHT above the tempering temperature.
What surface finishes work on AR450 Q&T-IT?
Supplied as mill/shot-blasted surface; protect with zinc-rich primer or industrial paint, or overlay/hardface wear faces — not anodizable and rarely polished.
Can AR450 Q&T-IT be formed, bent or molded?
Cold bending possible with min inside radius ≈4–5×t transverse to rolling direction (AR450F allows tighter); hot forming above ~250 °C destroys the hardness.
What is the maximum service temperature of AR450 Q&T-IT?
AR450 Q&T-IT 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.
Can FabDigit make parts in AR450 Q&T-IT?
Yes — AR450 Q&T-IT is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Abrasion-resistant quenched & tempered plate, 450 HBW class datasheets — SSAB / Nucor / ArcelorMittal (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- ASTM E140 / A370 hardness conversion and mechanical testing — ASTM (2021)
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.