Steel ZG35CrMnSi QT-45HRC
Hardness band
QT-45HRC = q&T 42–48 HRC
Maximum-hardness wear condition for liners, jaws and shovel teeth; low toughness, avoid high-impact or notched service.
Values for the QT-45HRC condition
Other ZG35CrMnSi tempers and conditions
ZG35CrMnSi is listed in 8 conditions; see the grade overview at ZG35CrMnSi.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — pick it for rough machining of large castings before final quench and temper. | 340 | 610 | 19 | 180 HB | — |
As fabricated | Cheapest condition for non-critical or later-heat-treated castings; coarse dendritic structure and high residual stress. | 390 | 660 | 8 | 19 HRC | 7.5 % IACS |
Stress relieved | Used after weld repair or heavy rough machining to remove residual stress without changing strength much. | 400 | 680 | 12 | 15 HRC | 7.5 % IACS |
N+TDefault Normalized and tempered | Standard supply condition to GB/T 14408 — balanced strength, ductility and toughness for general structural castings. | 460 | 760 | 15 | 20 HRC | — |
Normalized | Grain refinement and homogenization of the as-cast structure; usually followed by tempering. | 500 | 800 | 13 | 22 HRC | 7.4 % IACS |
Q&T 240–280 HB | General quenched-and-tempered condition when higher yield strength with retained toughness is needed in medium sections. | 700 | 900 | 12 | 26 HRC | — |
Q&T 300–340 HB | Higher-strength wear condition for crusher, excavator and mining castings where impact loads are moderate. | 850 | 1,050 | 9 | 34 HRC | — |
QT-45HRCThis page Q&T 42–48 HRC | Maximum-hardness wear condition for liners, jaws and shovel teeth; low toughness, avoid high-impact or notched service. | 1,250 | 1,500 | 5 | 45 HRC | — |
What is ZG35CrMnSi QT-45HRC?
ZG35CrMnSi QT-45HRC is ZG35CrMnSi heat treated to QT-45HRC — maximum-hardness wear condition for liners, jaws and shovel teeth; low toughness, avoid high-impact or notched service. ZG35CrMnSi QT-45HRC has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi). ZG35CrMnSi QT-45HRC has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,420°C (2,588 °F). N+T is the default condition FabDigit quotes; QT-45HRC is available on request or by drawing note.
Advantages
- High strength — 1,250 MPa (181 ksi), better than 95% of steel grades
Limitations
- Limited ductility — 5%, worse than 98% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 92% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
ZG35CrMnSi QT-45HRC properties
Typical room-temperature values for ZG35CrMnSi QT-45HRC; 12 are specific to this condition. Other listed values are ZG35CrMnSi reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
ZG35CrMnSi QT-45HRC has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical17
ZG35CrMnSi QT-45HRC has a yield strength of 1,250 MPa (181 ksi) and a tensile strength of 1,500 MPa (218 ksi) — stronger than 95% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
ZG35CrMnSi QT-45HRC is rated for continuous service to 200°C (392 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
ZG35CrMnSi QT-45HRC conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of ZG35CrMnSi QT-45HRC takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 85%.
Manufacturability7
ZG35CrMnSi QT-45HRC's machinability is poor (15/100, worse than 98% of steel grades); weldability fair (35/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZG35CrMnSi QT-45HRC
Is ZG35CrMnSi easy to machine?
Machine in the annealed or N+T state with rigid setups and carbide tooling; expect abrasive scale and sand inclusions on unmachined cast surfaces, so take a heavy first cut.
Can ZG35CrMnSi be welded?
Weldable only with care — CE ≈ 0.7–0.8, so preheat 200–300 °C, use low-hydrogen electrodes and stress-relieve or re-temper at 600–650 °C after welding.
Can ZG35CrMnSi be formed, bent or molded?
Sand or shell cast with generous risering and controlled cooling; the Si–Mn content raises hot-tearing risk at section changes, so fillet all junctions and use chills on heavy bosses.
What surface finishes work on ZG35CrMnSi?
Shot blast then prime — the steel rusts quickly; zinc-rich primer, painting, hard chrome or thermal-spray overlays are used, and flame or induction hardening can be applied to wear faces.
ZG35CrMnSi 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 | 0.3 – 0.4 | 0.35 |
| Si | 0.5 – 0.75 | 0.62 |
| Mn | 0.9 – 1.2 | 1.05 |
| Cr | 0.5 – 0.8 | 0.65 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.3 | — |
| Moresidual | ≤ 0.15 | — |
| Pimpurity max | ≤ 0.04 | — |
| Simpurity max | ≤ 0.04 | — |
| Fe | balance | — |
ZG35CrMnSi QT-45HRC — frequently asked
What is ZG35CrMnSi QT-45HRC used for?
ZG35CrMnSi QT-45HRC is typically used for mining equipment castings, excavator parts and wear-resistant heavy machinery components. In short: high-strength wear casting; hardenable to 45 HRC; weld with strict preheat.
What is the yield strength of ZG35CrMnSi QT-45HRC?
ZG35CrMnSi QT-45HRC has a typical yield strength of 1,250 MPa (181 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 ZG35CrMnSi QT-45HRC easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machine in the annealed or N+T state with rigid setups and carbide tooling; expect abrasive scale and sand inclusions on unmachined cast surfaces, so take a heavy first cut.
Can ZG35CrMnSi QT-45HRC be welded?
With care — weldability is rated fair (35/100). Weldable only with care — CE ≈ 0.7–0.8, so preheat 200–300 °C, use low-hydrogen electrodes and stress-relieve or re-temper at 600–650 °C after welding.
What surface finishes work on ZG35CrMnSi QT-45HRC?
Shot blast then prime — the steel rusts quickly; zinc-rich primer, painting, hard chrome or thermal-spray overlays are used, and flame or induction hardening can be applied to wear faces.
Can ZG35CrMnSi QT-45HRC be formed, bent or molded?
Sand or shell cast with generous risering and controlled cooling; the Si–Mn content raises hot-tearing risk at section changes, so fillet all junctions and use chills on heavy bosses.
What is the maximum service temperature of ZG35CrMnSi QT-45HRC?
ZG35CrMnSi QT-45HRC is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZG35CrMnSi N+T and ZG35CrMnSi-A?
N+T is the default condition — standard supply condition to GB/T 14408 — balanced strength, ductility and toughness for general structural castings. A: softest condition — pick it for rough machining of large castings before final quench and temper. Yield strength is 460 MPa in N+T versus 340 MPa in A.
Sources
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast low-alloy steels) — ASM International (1990)
- ASTM A148/A148M — Steel Castings, High Strength, for Structural Purposes — ASTM (2020)
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.