Steel ZG310-570-SR (Stress relieved)
Heat-treated state
GB GB/T 11352
Pick when dimensional stability and low residual stress matter more than peak strength (large weldments and machined frames).
Values for the SR condition
Other ZG310-570 tempers and conditions
ZG310-570 is listed in 6 conditions; see the grade overview at ZG310-570.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — chosen to maximise machinability before final hardening, or to relieve hard-to-machine as-cast structure. | 305 | 570 | 20 | 165 HB | 10 % IACS |
SRThis page Stress relieved | Pick when dimensional stability and low residual stress matter more than peak strength (large weldments and machined frames). | 315 | 575 | 18 | 175 HB | 10 % IACS |
As fabricated | Cheapest condition for lightly stressed or thin-section castings where GB minimums are met as-cast. | 320 | 585 | 15 | 185 HB | 10 % IACS |
N+TDefault Normalized and tempered | Default supply condition: refined grain plus tempering gives the best balance of GB minimums, toughness and machinability. | 340 | 600 | 19 | 185 HB | — |
Normalized | Refines the coarse as-cast grain for uniform strength; standard treatment for general structural castings. | 350 | 620 | 18 | 195 HB | — |
Quenched and tempered | Choose for heavily loaded gears, sprockets and links needing higher yield and wear resistance in moderate section sizes. | 550 | 760 | 14 | 22 HRC | — |
What is ZG310-570-SR?
ZG310-570-SR is ZG310-570 heat treated to SR — pick when dimensional stability and low residual stress matter more than peak strength (large weldments and machined frames). ZG310-570-SR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 575 MPa (83.4 ksi) — weaker than 82% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi). ZG310-570-SR 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). N+T is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Limited formability — 14/100, worse than 90% of steel grades
- Low strength — 315 MPa (45.7 ksi), worse than 82% of steel grades
- Low fracture toughness — 58 MPa·√m (52.8 ksi·√in), worse than 80% of steel grades
ZG310-570-SR properties
Typical room-temperature values for ZG310-570-SR; 22 are specific to this condition. Other listed values are ZG310-570 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
ZG310-570-SR 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
ZG310-570-SR has a yield strength of 315 MPa (45.7 ksi) and a tensile strength of 575 MPa (83.4 ksi) — weaker than 82% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
ZG310-570-SR is rated for continuous service to 400°C (752 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
ZG310-570-SR conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of ZG310-570-SR takes about 27 MJ of energy and emits 2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 85%.
Manufacturability8
ZG310-570-SR's machinability is fair (52/100, better than 52% of steel grades); weldability fair (45/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZG310-570-SR
Is ZG310-570 easy to machine?
Machines like 1045 at ~55 % of AISI 1212; anneal or temper first, remove hard cast skin with carbide tooling and expect scattered sand/oxide inclusions.
Can ZG310-570 be welded?
Weldable with low-hydrogen E7018/ER70S-6 but the 0.45 % C requires 150–250 °C preheat, controlled interpass and 600–650 °C post-weld stress relief to avoid HAZ cracking.
Can ZG310-570 be formed, bent or molded?
Green-sand, resin-sand or shell casting with generous risering and 1560–1600 °C pour; high solidification shrinkage (~2 %) demands directional feeding and generous fillets.
What surface finishes work on ZG310-570?
Shot-blast then paint, phosphate + oil, zinc or hard-chrome plate; bare surfaces rust quickly and anodizing does not apply.
ZG310-570 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 |
|---|---|---|
| CGB/T 11352 upper limit; ≈0.45 % typical (hence old name ZG45) | ≤ 0.5 | 0.45 |
| Si | ≤ 0.6 | 0.4 |
| Mn | ≤ 0.9 | 0.7 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Crresidual element | ≤ 0.35 | — |
| Niresidual element | ≤ 0.3 | — |
| Curesidual element | ≤ 0.3 | — |
| Moresidual element | ≤ 0.2 | — |
| Vresidual element; total residuals ≤1.00 % | ≤ 0.05 | — |
| Fe | balance | — |
ZG310-570-SR — frequently asked
What is ZG310-570-SR used for?
ZG310-570-SR is typically used for heavy machine frames, large gears, crusher parts and railway castings. In short: strongest grade in family; surface-hardenable cast steel; preheat required for welding.
What is the yield strength of ZG310-570-SR?
ZG310-570-SR has a typical yield strength of 315 MPa (45.7 ksi) and a tensile strength of 575 MPa (83.4 ksi) — weaker than 82% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is ZG310-570-SR easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like 1045 at ~55 % of AISI 1212; anneal or temper first, remove hard cast skin with carbide tooling and expect scattered sand/oxide inclusions.
Can ZG310-570-SR be welded?
With care — weldability is rated fair (45/100). Weldable with low-hydrogen E7018/ER70S-6 but the 0.45 % C requires 150–250 °C preheat, controlled interpass and 600–650 °C post-weld stress relief to avoid HAZ cracking.
What surface finishes work on ZG310-570-SR?
Shot-blast then paint, phosphate + oil, zinc or hard-chrome plate; bare surfaces rust quickly and anodizing does not apply.
Can ZG310-570-SR be formed, bent or molded?
Green-sand, resin-sand or shell casting with generous risering and 1560–1600 °C pour; high solidification shrinkage (~2 %) demands directional feeding and generous fillets.
What is the maximum service temperature of ZG310-570-SR?
ZG310-570-SR 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 ZG310-570 N+T and ZG310-570-A?
N+T is the default condition — default supply condition: refined grain plus tempering gives the best balance of GB minimums, toughness and machinability. A: softest condition — chosen to maximise machinability before final hardening, or to relieve hard-to-machine as-cast structure. Yield strength is 340 MPa in N+T versus 305 MPa in A.
Sources
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast carbon steels) — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- Steel Castings Handbook (SFSA) mechanical & machinability data — Steel Founders' Society of America (1995)
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.