Steel ZG55SiMnMo
ZG55SiMnMo is a high-carbon silicon-manganese-molybdenum cast steel developed for abrasion and impact service, available as-cast, annealed, normalized and tempered, austempered, or quenched and tempered to 40-45, 45-50 and 50-55 HRC.
Reference datasheet — ZG55SiMnMo is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT45-50HRC condition
ZG55SiMnMo tempers and conditions
ZG55SiMnMo is supplied in 7 conditions, soft to hard. QT45-50HRC is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick for stress relief and softest structure before rough machining or welding repair of the casting. | 400 | 700 | 14 | 210 HB | — |
As fabricated | Cheapest condition, only for low-stress or rough non-critical castings; coarse as-cast structure with residual casting stresses. | 430 | 750 | 6 | 26 HRC | 6.5 % IACS |
Normalized and tempered | Balanced strength/toughness for large or thick-walled castings where oil/water quenching would crack them. | 650 | 950 | 10 | 31 HRC | — |
quenched and tempered ~350–420 °C | Choose when impact loading dominates over pure abrasion (crusher jaws, hammer bodies, shovel teeth). | 1,150 | 1,400 | 7 | 42 HRC | — |
Austempered / isothermally quenched to lower bainite | Use for heavy-impact wear parts needing 45–50 HRC with clearly higher toughness and lower distortion/cracking risk than martensitic Q&T. | 1,200 | 1,500 | 8 | 47 HRC | — |
QT45-50HRCDefault quenched (oil/water-mist) and tempered ~250–320 °C | Standard supply condition for ball-mill liners and crusher wear parts — best compromise of abrasion resistance and impact toughness. | 1,300 | 1,600 | 5 | 47 HRC | — |
quenched and low-temperature tempered ~180–230 °C | Maximum abrasion resistance for fine-grinding liners, chute plates and sand-slurry parts where impact energy is low. | 1,450 | 1,800 | 3 | 53 HRC | — |
What is ZG55SiMnMo?
ZG55SiMnMo is a high-carbon silicon-manganese-molybdenum cast steel developed for abrasion and impact service, available as-cast, annealed, normalized and tempered, austempered, or quenched and tempered to 40-45, 45-50 and 50-55 HRC. It is used for crusher and mill wear parts because the quenched-and-tempered condition reaches 1300 MPa yield, 1600 MPa tensile and 460 HB (47 HRC) with usable toughness. The trade-offs are 5 % elongation, a machinability score of only 15, a 350 °C service limit and high weld cracking sensitivity. For heavy gouging impact, austenitic manganese steel is the usual alternative. ZG55SiMnMo has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F). ZG55SiMnMo has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi).
What is ZG55SiMnMo used for?
- Crusher hammers
- Ball mill liners
- Excavator teeth
Advantages
- High strength — 1,300 MPa (189 ksi), better than 95% of steel grades
Limitations
- Limited formability — 5/100, worse than 99% of steel grades
- Limited ductility — 5%, worse than 98% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% of steel grades
- Low electrical conductivity — 6.2 % IACS, worse than 78% of steel grades
ZG55SiMnMo properties
Typical room-temperature values for ZG55SiMnMo-QT45-50HRC; bars are the position among steel grades.
Physical3
ZG55SiMnMo has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
ZG55SiMnMo has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 5% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
ZG55SiMnMo is rated for continuous service to 350°C (662 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
ZG55SiMnMo conducts electricity at 6.2 % IACS, worse than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of ZG55SiMnMo takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 80%.
Manufacturability8
ZG55SiMnMo's machinability is poor (15/100, worse than 98% of steel grades); weldability poor (25/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. ZG55SiMnMo is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZG55SiMnMo
Is ZG55SiMnMo easy to machine?
Rough-machine in the annealed or as-cast state; above ~45 HRC use CBN/ceramic inserts or grinding, rigid setups and low feeds.
Can ZG55SiMnMo be welded?
Crack-sensitive (high CE): preheat 250–350 °C, low-hydrogen or austenitic-buffer electrodes, and temper immediately after welding; keep welds out of high-stress wear zones.
Can ZG55SiMnMo be formed, bent or molded?
Sand-cast only — provide generous fillets and directional feeding, control Si-related shrinkage porosity, and always normalize or quench-and-temper before service.
ZG55SiMnMo 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 |
|---|---|---|
| Cgrade-defining carbon level | 0.5 – 0.6 | 0.55 |
| Sisome works standards run Si up to 1.6–2.0 % for extra solid-solution strength | 0.8 – 1.2 | 1 |
| Mn | 1.1 – 1.6 | 1.35 |
| Mohardenability + temper-embrittlement resistance | 0.2 – 0.35 | 0.28 |
| Crresidual, sometimes added intentionally | ≤ 0.3 | |
| Niresidual | ≤ 0.3 | |
| Pimpurity limit | ≤ 0.04 | |
| Simpurity limit | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on ZG55SiMnMo?
Shot-blast and paint or oil for storage; no anodizing. Hard-facing overlays or phosphate coatings are common for extra service life.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does ZG55SiMnMo cost?
ZG55SiMnMo is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZG55SiMnMo — frequently asked
What is ZG55SiMnMo used for?
ZG55SiMnMo is typically used for crusher hammers, ball mill liners and excavator teeth. In short: hardest cast wear grade; 460 HB in service; abrasion-first cast steel.
What is the yield strength of ZG55SiMnMo?
ZG55SiMnMo has a typical yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is ZG55SiMnMo easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Rough-machine in the annealed or as-cast state; above ~45 HRC use CBN/ceramic inserts or grinding, rigid setups and low feeds.
Can ZG55SiMnMo be welded?
Not readily — weldability is rated poor (25/100). Crack-sensitive (high CE): preheat 250–350 °C, low-hydrogen or austenitic-buffer electrodes, and temper immediately after welding; keep welds out of high-stress wear zones.
What surface finishes work on ZG55SiMnMo?
Shot-blast and paint or oil for storage; no anodizing. Hard-facing overlays or phosphate coatings are common for extra service life.
Can ZG55SiMnMo be formed, bent or molded?
Sand-cast only — provide generous fillets and directional feeding, control Si-related shrinkage porosity, and always normalize or quench-and-temper before service.
What is the maximum service temperature of ZG55SiMnMo?
ZG55SiMnMo is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZG55SiMnMo QT45-50HRC and ZG55SiMnMo-A?
QT45-50HRC is the default condition — standard supply condition for ball-mill liners and crusher wear parts — best compromise of abrasion resistance and impact toughness. A: pick for stress relief and softest structure before rough machining or welding repair of the casting. Yield strength is 1,300 MPa in QT45-50HRC versus 400 MPa in A.
How much does ZG55SiMnMo cost?
ZG55SiMnMo is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 26651 (Wear-resistant steel castings) (2011)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (steel castings, Q&T low-alloy steel) — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.