Steel 30CrMnSiNi2A Annealed
Temper
EN 30CrMnSiNi2A
Soft delivery condition for machining, cold straightening and forging stock before final quench and temper.
Values for the Annealed condition
Other 30CrMnSiNi2A tempers and conditions
30CrMnSiNi2A is listed in 10 conditions; see the grade overview at 30CrMnSiNi2A.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedThis page (mill delivery condition for bar/forging stock) | Soft delivery condition for machining, cold straightening and forging stock before final quench and temper. | 560 | 800 | 18 | 217 HB | — |
Cold drawn + annealed bar | Small-diameter precision bar for fasteners and pins, machined then heat treated to final strength. | 720 | 900 | 12 | 25 HRC | 6.4 % IACS |
Normalized + high-temperature temper | Alternative pre-machining condition giving a uniform sorbitic structure and better machined surface than full anneal. | 750 | 950 | 16 | 27 HRC | 6.4 % IACS |
Q&T 500–550 °C | Use when maximum toughness, machinability and reduced SCC/hydrogen sensitivity matter more than peak strength. | 1,150 | 1,280 | 15 | 39 HRC | — |
Isothermal quench (austemper, lower bainite) | Choose for complex thin-section forgings where distortion and quench cracking must be minimised and impact toughness maximised. | 1,300 | 1,550 | 14 | 45 HRC | — |
Q&T 400 °C | Listed for reference only — tempering near 350–450 °C causes a sharp drop in impact energy and should be avoided. | 1,350 | 1,500 | 12 | 44 HRC | 5.9 % IACS |
Q&T 300 °C | Slightly lower strength with improved toughness and hot-strength retention; upper limit before temper embrittlement. | 1,400 | 1,630 | 13 | 46 HRC | — |
QT260Default Q&T 260 °C | Standard aerospace condition — best balance of 1620–1800 MPa strength, ductility and K_IC for landing gear and structural fittings. | 1,450 | 1,700 | 12 | 48 HRC | — |
As-quenched (untempered martensite) | Intermediate condition only — never used in service because untempered martensite is brittle and quench-crack prone. | 1,550 | 2,000 | 5 | 54 HRC | 4.5 % IACS |
Q&T 200 °C | Maximum-strength condition for short-life or stiffness-critical parts where toughness and SCC resistance are less critical. | 1,550 | 1,820 | 10 | 51 HRC | — |
What is 30CrMnSiNi2A Annealed?
30CrMnSiNi2A Annealed is 30CrMnSiNi2A in the Annealed temper — soft delivery condition for machining, cold straightening and forging stock before final quench and temper. 30CrMnSiNi2A Annealed has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 73% of steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi). 30CrMnSiNi2A Annealed 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). QT260 is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to weld — 20/100, worse than 84% of steel grades
- Poor heat conductor — 31 W/m·K (17.9 BTU/hr·ft·°F), worse than 83% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Low electrical conductivity — 5.7 % IACS, worse than 80% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
30CrMnSiNi2A Annealed properties
Typical room-temperature values for 30CrMnSiNi2A Annealed; 11 are specific to this condition. Other listed values are 30CrMnSiNi2A reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
30CrMnSiNi2A Annealed 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).
Mechanical15
30CrMnSiNi2A Annealed has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 73% of steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
30CrMnSiNi2A Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 31 W/m·K (17.9 BTU/hr·ft·°F), worse than 83% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
30CrMnSiNi2A Annealed conducts electricity at 5.7 % IACS, worse than 80% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 30CrMnSiNi2A Annealed takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 20%.
Manufacturability7
30CrMnSiNi2A Annealed's machinability is fair (48/100, worse than 57% of steel grades); weldability poor (20/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 30CrMnSiNi2A Annealed
Is 30CrMnSiNi2A easy to machine?
Rough-machine in the annealed condition (HB ≤229); finish cuts on hardened 48 HRC material need rigid setups, coated carbide or CBN, low feeds and generous coolant, leaving stock for grinding.
Can 30CrMnSiNi2A be welded?
Poor weldability — if unavoidable use TIG/EB with matching or low-hydrogen filler, 250–350 °C preheat, and re-quench-and-temper the whole part; never weld in the final heat-treated state.
Can 30CrMnSiNi2A be formed, bent or molded?
Hot forge 1150→900 °C with slow post-forge cooling and immediate anneal; cold forming is limited to gentle straightening in the annealed state.
What surface finishes work on 30CrMnSiNi2A?
Shot-peen highly stressed fillets, then cadmium, Zn-Ni or IVD aluminium plate plus primer; bake 190–200 °C for 8–24 h after plating or acid pickling to relieve hydrogen, and avoid grinding burns.
30CrMnSiNi2A 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 | 0.27 – 0.34 | 0.3 |
| Siraises tempering resistance | 0.9 – 1.2 | 1.05 |
| Mn | 1 – 1.3 | 1.15 |
| Cr | 0.9 – 1.2 | 1.05 |
| Nitoughness and hardenability | 1.4 – 1.8 | 1.6 |
| Curesidual | ≤ 0.2 | — |
| Saerospace melt practice, often ≤0.008 | ≤ 0.01 | — |
| P | ≤ 0.02 | — |
| Fe | balance | — |
30CrMnSiNi2A Annealed — frequently asked
What is 30CrMnSiNi2A Annealed used for?
30CrMnSiNi2A Annealed is typically used for landing gear, aircraft structural forgings and high-strength shafts. In short: 300M-class strength level; silicon-modified temper resistance; landing gear workhorse grade.
What is the yield strength of 30CrMnSiNi2A Annealed?
30CrMnSiNi2A Annealed has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 30CrMnSiNi2A Annealed easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Rough-machine in the annealed condition (HB ≤229); finish cuts on hardened 48 HRC material need rigid setups, coated carbide or CBN, low feeds and generous coolant, leaving stock for grinding.
Can 30CrMnSiNi2A Annealed be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — if unavoidable use TIG/EB with matching or low-hydrogen filler, 250–350 °C preheat, and re-quench-and-temper the whole part; never weld in the final heat-treated state.
What surface finishes work on 30CrMnSiNi2A Annealed?
Shot-peen highly stressed fillets, then cadmium, Zn-Ni or IVD aluminium plate plus primer; bake 190–200 °C for 8–24 h after plating or acid pickling to relieve hydrogen, and avoid grinding burns.
Can 30CrMnSiNi2A Annealed be formed, bent or molded?
Hot forge 1150→900 °C with slow post-forge cooling and immediate anneal; cold forming is limited to gentle straightening in the annealed state.
What is the maximum service temperature of 30CrMnSiNi2A Annealed?
30CrMnSiNi2A Annealed 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 30CrMnSiNi2A-QT260 and 30CrMnSiNi2A-QT520?
QT260 is the default condition — standard aerospace condition — best balance of 1620–1800 MPa strength, ductility and K_IC for landing gear and structural fittings. QT520: use when maximum toughness, machinability and reduced SCC/hydrogen sensitivity matter more than peak strength. Yield strength is 1,450 MPa in QT260 versus 1,150 MPa in QT520.
Sources
- GJB / (30CrMnSiNi2A) (1994)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- MMPDS-17 (300M / AMS 6417 comparison data) — Battelle (2022)
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.