Steel G34CrMo4 +QT2
Heat-treated state
EN 1.7230
+QT2 = quenched and tempered, higher strength class
Pick when ~850–1000 MPa tensile strength and higher wear resistance are needed and section thickness stays modest; ductility and impact energy drop accordingly.
Values for the +QT2 condition
Other G34CrMo4 tempers and conditions
G34CrMo4 is listed in 4 conditions; see the grade overview at G34CrMo4.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for rough castings that will be heavily machined before the final quench and temper. | 360 | 620 | 19 | 185 HB | — |
Normalized | Use for thick or geometrically complex castings where quenching risk (distortion/cracking) outweighs the need for peak strength. | 460 | 700 | 15 | 17 HRC | — |
+QT1Default Quenched and tempered, lower strength class | Standard supply condition: good balance of ~700–850 MPa tensile strength with usable toughness for general machinery and structural castings. | 570 | 760 | 14 | 22 HRC | — |
+QT2This page Quenched and tempered, higher strength class | Pick when ~850–1000 MPa tensile strength and higher wear resistance are needed and section thickness stays modest; ductility and impact energy drop accordingly. | 730 | 900 | 11 | 30 HRC | — |
What is G34CrMo4 +QT2?
G34CrMo4 +QT2 is G34CrMo4 heat treated to +QT2 — pick when ~850–1000 MPa tensile strength and higher wear resistance are needed and section thickness stays modest; ductility and impact energy drop accordingly. G34CrMo4 +QT2 has a yield strength of 730 MPa (106 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 83% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi). G34CrMo4 +QT2 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F). +QT1 is the default condition FabDigit quotes; +QT2 is available on request or by drawing note.
Advantages
- High strength — 730 MPa (106 ksi), better than 83% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Limited ductility — 11%, worse than 89% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
G34CrMo4 +QT2 properties
Typical room-temperature values for G34CrMo4 +QT2; 18 are specific to this condition. Other listed values are G34CrMo4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G34CrMo4 +QT2 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
G34CrMo4 +QT2 has a yield strength of 730 MPa (106 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 83% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G34CrMo4 +QT2 is rated for continuous service to 380°C (716 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
G34CrMo4 +QT2 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of G34CrMo4 +QT2 takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 75%.
Manufacturability8
G34CrMo4 +QT2's machinability is fair (42/100, worse than 73% of steel grades); weldability poor (33/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G34CrMo4 +QT2
Is G34CrMo4 easy to machine?
Machine in +A or +N condition where possible; in +QT2 use rigid setups, coated carbide and moderate speeds (~80–120 m/min) with positive feed to avoid work-hardened glazing.
Can G34CrMo4 be welded?
Weldable with care only: preheat 250–350 °C, low-hydrogen consumables (matching CrMo or E7018-type), maintain interpass and apply 600–650 °C PWHT to avoid HAZ cracking.
Can G34CrMo4 be formed, bent or molded?
Sand or investment cast with generous risering; the alloy has moderate fluidity and needs directional solidification plus stress-relief after shakeout to control hot tearing.
What surface finishes work on G34CrMo4?
No anodizing; protect with shot blast plus primer/paint, zinc or phosphate coating; hard-chrome, nitriding or induction hardening are used for local wear surfaces.
G34CrMo4 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 – 0.37 | 0.34 |
| Si | ≤ 0.6 | 0.4 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Cr | 0.8 – 1.2 | 1 |
| Mo | 0.15 – 0.3 | 0.22 |
| Niresidual | ≤ 0.4 | 0.15 |
| Fe | balance | — |
G34CrMo4 +QT2 — frequently asked
What is G34CrMo4 +QT2 used for?
G34CrMo4 +QT2 is typically used for machinery frames, gear housings and structural castings requiring heat treatment. In short: higher strength than G26CrMo4; quench-and-temper cast CrMo; structural machinery castings.
What is the yield strength of G34CrMo4 +QT2?
G34CrMo4 +QT2 has a typical yield strength of 730 MPa (106 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 83% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is G34CrMo4 +QT2 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in +A or +N condition where possible; in +QT2 use rigid setups, coated carbide and moderate speeds (~80–120 m/min) with positive feed to avoid work-hardened glazing.
Can G34CrMo4 +QT2 be welded?
Not readily — weldability is rated poor (33/100). Weldable with care only: preheat 250–350 °C, low-hydrogen consumables (matching CrMo or E7018-type), maintain interpass and apply 600–650 °C PWHT to avoid HAZ cracking.
What surface finishes work on G34CrMo4 +QT2?
No anodizing; protect with shot blast plus primer/paint, zinc or phosphate coating; hard-chrome, nitriding or induction hardening are used for local wear surfaces.
Can G34CrMo4 +QT2 be formed, bent or molded?
Sand or investment cast with generous risering; the alloy has moderate fluidity and needs directional solidification plus stress-relief after shakeout to control hot tearing.
What is the maximum service temperature of G34CrMo4 +QT2?
G34CrMo4 +QT2 is rated for continuous use to about 380°C (716 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10293 — Steel castings for general engineering uses — CEN (2015)
- GB/T 14408 / JB/T 6402 — (ZG35CrMo) (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Steel Castings Handbook — 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.