Steel E730K2 +QT (Quenched and tempered)
Heat-treated state · default condition
EN 1.8893
Standard supply condition; the only state that meets the 730 MPa yield and -20 °C impact requirements.
Values for the +QT condition
Other E730K2 tempers and conditions
E730K2 is listed in 3 conditions; see the grade overview at E730K2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose when heavy machining or cold forming precedes a final quench-and-temper by the part maker. | 400 | 620 | 22 | 11 HRC | 8 % IACS |
Normalized | Used only as an intermediate grain-refining state before final quench and temper; strength stays well below the grade minimum. | 470 | 700 | 19 | 16 HRC | 7.5 % IACS |
+QTDefaultThis page Quenched and tempered | Standard supply condition; the only state that meets the 730 MPa yield and -20 °C impact requirements. | 780 | 870 | 14 | 27 HRC | — |
What is E730K2 +QT?
E730K2 +QT is E730K2 heat treated to +QT — standard supply condition; the only state that meets the 730 MPa yield and -20 °C impact requirements. E730K2 +QT has a yield strength of 780 MPa (113 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). E730K2 +QT 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).
Advantages
- High strength — 780 MPa (113 ksi), better than 86% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
E730K2 +QT properties
Typical room-temperature values for E730K2 +QT; 12 are specific to this condition. Other listed values are E730K2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E730K2 +QT 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
E730K2 +QT has a yield strength of 780 MPa (113 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
E730K2 +QT is rated for continuous service to 300°C (572 °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 µm/m·K (6.67 µin/in·°F).
Electrical3
E730K2 +QT conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of E730K2 +QT takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
E730K2 +QT's machinability is fair (45/100, worse than 65% of steel grades); weldability good (55/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E730K2 +QT
Is E730K2 easy to machine?
Machine in +A condition where possible; in +QT use rigid setups, coated carbide, moderate speed and generous feed to stay below the work-hardened skin.
Can E730K2 be welded?
Weldable with low-hydrogen consumables and controlled heat input; preheat 100–150 °C (thicker/higher CEV sections more) and avoid slow cooling that softens the HAZ.
Can E730K2 be formed, bent or molded?
Cold bending needs generous inner radii (typically ≥3–4 t across the rolling direction) and deburred, crack-free edges; hot forming above the tempering temperature requires re-quenching and tempering.
What surface finishes work on E730K2?
No anodizing; protect by shot-blast plus epoxy/zinc-rich paint, hot-dip galvanizing (watch for liquid-metal-assisted cracking in highly stressed parts) or zinc-nickel plating with post-bake to avoid hydrogen embrittlement.
E730K2 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 |
|---|---|---|
| Cindicative for EN quenched-and-tempered high-strength engineering steels; confirm on mill certificate | ≤ 0.22 | 0.18 |
| Si | ≤ 0.6 | 0.3 |
| Mn | 0.8 – 1.7 | 1.3 |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| Crhardenability addition, producer-dependent | ≤ 1.5 | 0.6 |
| Nifor low-temperature toughness | ≤ 2 | 0.6 |
| Mo | ≤ 0.7 | 0.3 |
| Vmicroalloying | ≤ 0.12 | 0.05 |
| Ti | ≤ 0.05 | — |
| Nb | ≤ 0.06 | — |
| Bboron-treated for hardenability in thin sections | ≤ 0.01 | 0 |
| Cu | ≤ 0.5 | — |
| Altotal Al for fine grain / N binding | ≥ 0.02 | 0.03 |
| Fe | balance | — |
E730K2 +QT — frequently asked
What is E730K2 +QT used for?
E730K2 +QT is typically used for heavy machinery components, high-strength structural parts, load-bearing shafts and mobile equipment structures. In short: highest-strength E-series grade; toughness at -20 °C; limited formability.
What is the yield strength of E730K2 +QT?
E730K2 +QT has a typical yield strength of 780 MPa (113 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is E730K2 +QT easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in +A condition where possible; in +QT use rigid setups, coated carbide, moderate speed and generous feed to stay below the work-hardened skin.
Can E730K2 +QT be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen consumables and controlled heat input; preheat 100–150 °C (thicker/higher CEV sections more) and avoid slow cooling that softens the HAZ.
What surface finishes work on E730K2 +QT?
No anodizing; protect by shot-blast plus epoxy/zinc-rich paint, hot-dip galvanizing (watch for liquid-metal-assisted cracking in highly stressed parts) or zinc-nickel plating with post-bake to avoid hydrogen embrittlement.
Can E730K2 +QT be formed, bent or molded?
Cold bending needs generous inner radii (typically ≥3–4 t across the rolling direction) and deburred, crack-free edges; hot forming above the tempering temperature requires re-quenching and tempering.
What is the maximum service temperature of E730K2 +QT?
E730K2 +QT is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10027-1 Designation systems for steels — Part 1: Steel names — CEN (2016)
- EN 10027-2 Designation systems for steels — Part 2: Numerical system — CEN (2015)
- EN 10083-3 Steels for quenching and tempering — Alloy steels — CEN (2006)
- EN 10025-6 Hot rolled products — Flat products of high yield strength structural steels in the quenched and tempered condition — CEN (2019)
- ASM Handbook Vol. 1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
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.