Steel ZG340-640 Normalized
Heat-treated state · default condition
GB GB/T 11352
Default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance.
Values for the Normalized condition
Other ZG340-640 tempers and conditions
ZG340-640 is listed in 6 conditions; see the grade overview at ZG340-640.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal (~840–870 °C, furnace cool) | Pick when maximum machinability and stress relief matter more than strength, e.g. before heavy rough machining. | 320 | 600 | 14 | 180 HB | — |
As fabricated | Lowest-cost condition for non-critical wear parts where cast-in stresses and coarse structure are acceptable. | 330 | 630 | 8 | 14 HRC | 8.6 % IACS |
NormalizedDefaultThis page 850–880 °C, air cool (standard GB/T 11352 delivery) | Default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance. | 360 | 660 | 11 | 210 HB | — |
Normalized and tempered | Use when residual stresses from normalizing must be relieved while keeping spec strength and slightly better toughness. | 370 | 670 | 13 | 17 HRC | 8.6 % IACS |
Quenched and tempered | Highest strength/toughness combination for heavily loaded gears and rolls; section size limited by hardenability and quench-crack risk at 0.55%C. | 550 | 800 | 12 | 26 HRC | — |
Quenched and low-tempered for wear | Choose for abrasion-dominated castings (crusher parts, wear plates) where hardness outranks impact toughness. | 750 | 1,000 | 6 | 34 HRC | — |
What is ZG340-640 Normalized?
ZG340-640 Normalized is ZG340-640 heat treated to Normalized — default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance. ZG340-640 Normalized has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi). ZG340-640 Normalized has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F).
Limitations
- Limited ductility — 11%, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
ZG340-640 Normalized properties
Typical room-temperature values for ZG340-640 Normalized; 12 are specific to this condition. Other listed values are ZG340-640 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
ZG340-640 Normalized has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
ZG340-640 Normalized has a yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
ZG340-640 Normalized is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
ZG340-640 Normalized conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of ZG340-640 Normalized takes about 24 MJ of energy and emits 2 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 80%.
Manufacturability8
ZG340-640 Normalized's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZG340-640 Normalized
Is ZG340-640 easy to machine?
As a 0.5 % C pearlitic cast steel it cuts normally in the normalized condition with coated carbide at vc ≈ 100–150 m/min. Hard spots and residual sand in the as-cast skin chip cutting edges, so remove the skin layer first; in the Q&T condition reduce speed and increase feed.
Can ZG340-640 be welded?
Carbon equivalent is high (about 0.6–0.75), so weldability is poor: preheat to 150–250 °C, use low-hydrogen electrodes (E7015/E7016 or E5015), control interpass temperature and stress relieve at 600–650 °C after welding, otherwise cold cracking is likely.
Can ZG340-640 be formed, bent or molded?
Mainly sand cast at a pouring temperature of about 1540–1580 °C with roughly 2 % linear shrinkage; provide enough risers and chills to avoid shrinkage cavities. Abrupt thick-to-thin transitions hot tear, so keep wall thickness uniform and use generous fillet radii.
What surface finishes work on ZG340-640?
Not anodizable; after shot blasting apply phosphate plus primer or epoxy paint, zinc plating or black oxide for rust protection. Sliding wear faces can be flame or induction hardened, or nitrided, to raise surface hardness.
ZG340-640 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 caps C ≤0.60; held near 0.5 % for strength | 0.45 – 0.6 | 0.55 |
| Si | 0.2 – 0.6 | 0.45 |
| Mn | 0.5 – 0.9 | 0.8 |
| Pmaximum, general use | ≤ 0.04 | 0.02 |
| Smaximum, general use | ≤ 0.04 | 0.02 |
| Niresidual element | ≤ 0.3 | — |
| Crresidual element | ≤ 0.35 | — |
| Curesidual element | ≤ 0.3 | — |
| Moresidual element | ≤ 0.2 | — |
| Vresidual element; total residuals ≤1.00 % | ≤ 0.05 | — |
| Fe | balance | — |
ZG340-640 Normalized — frequently asked
What is ZG340-640 Normalized used for?
ZG340-640 Normalized is typically used for crusher hammers, large gears, heavy-duty machine bases and mining equipment parts. In short: strongest common GB/T 11352 tier; wear-resistant cast steel; poor weldability, high CE.
What is the yield strength of ZG340-640 Normalized?
ZG340-640 Normalized has a typical yield strength of 360 MPa (52.2 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 72% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is ZG340-640 Normalized easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). As a 0.5 % C pearlitic cast steel it cuts normally in the normalized condition with coated carbide at vc ≈ 100–150 m/min. Hard spots and residual sand in the as-cast skin chip cutting edges, so remove the skin layer first; in the Q&T condition reduce speed and increase feed.
Can ZG340-640 Normalized be welded?
With care — weldability is rated fair (35/100). Carbon equivalent is high (about 0.6–0.75), so weldability is poor: preheat to 150–250 °C, use low-hydrogen electrodes (E7015/E7016 or E5015), control interpass temperature and stress relieve at 600–650 °C after welding, otherwise cold cracking is likely.
What surface finishes work on ZG340-640 Normalized?
Not anodizable; after shot blasting apply phosphate plus primer or epoxy paint, zinc plating or black oxide for rust protection. Sliding wear faces can be flame or induction hardened, or nitrided, to raise surface hardness.
Can ZG340-640 Normalized be formed, bent or molded?
Mainly sand cast at a pouring temperature of about 1540–1580 °C with roughly 2 % linear shrinkage; provide enough risers and chills to avoid shrinkage cavities. Abrupt thick-to-thin transitions hot tear, so keep wall thickness uniform and use generous fillet radii.
What is the maximum service temperature of ZG340-640 Normalized?
ZG340-640 Normalized 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 ZG340-640 Normalized and ZG340-640-F?
Normalized is the default condition — default stocked condition: meets the 340/640 MPa spec with uniform fine pearlitic structure and good wear resistance. F: lowest-cost condition for non-critical wear parts where cast-in stresses and coarse structure are acceptable. Yield strength is 360 MPa in Normalized versus 330 MPa in F.
Sources
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Cast Steels) — ASM International (1990)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
- ASTM A27/A148 (comparable cast carbon steel grades) — ASTM International (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.