Steel 20CrMnTi Isothermal Annealed
Heat-treated state
GB 20CrMnTi
Preferred pre-machining treatment for gear blanks: uniform ferrite–pearlite structure, low hardness scatter and better heat-treat dimensional stability.
Values for the Isothermal Annealed condition
Other 20CrMnTi tempers and conditions
20CrMnTi is listed in 8 conditions; see the grade overview at 20CrMnTi.
- Annealed
- Isothermal Annealed
- High-Temp Tempered
- Normalized
- Hot Rolled
- Cold Drawn
- Q&T 200C
- Carburized 58-62 HRC
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault softened for machining (≤217 HB) | Standard stock condition for bar and forgings that will be machined then carburized. | 400 | 620 | 22 | 187 HB | — |
Isothermal AnnealedThis page 930 °C austenitize, hold ~630 °C, air cool | Preferred pre-machining treatment for gear blanks: uniform ferrite–pearlite structure, low hardness scatter and better heat-treat dimensional stability. | 410 | 640 | 22 | 180 HB | 7.8 % IACS |
GB/T 3077 alternative delivery condition (≤217 HB) | Mill delivery softening alternative to annealing when hardness must be capped at 217 HB for machining. | 430 | 650 | 21 | 197 HB | 7.8 % IACS |
~880–920 °C, air cool | Used to refine forging structure and homogenize before final machining/carburizing; harder than annealed. | 480 | 750 | 18 | 217 HB | 7.8 % IACS |
as-rolled bar, no post-rolling heat treatment | Cheapest bar form; hardness and structure vary with section and cooling, normally re-annealed before machining. | 500 | 780 | 16 | 20 HRC | 7.8 % IACS |
cold-finished bar (annealed then drawn) | Choose for tight tolerance, bright small-diameter bar for shafts and pins with reduced machining allowance. | 650 | 780 | 10 | 22 HRC | 7.8 % IACS |
Q&T | The standard-specified property condition; also used for through-hardened small parts needing very high strength. | 930 | 1,180 | 12 | 40 HRC | — |
Carburized, quenched and low-temperature tempered | The service condition for gears, splines and shafts: hard wear-resistant case with tough core and high bending fatigue strength. | 950 | 1,200 | 10 | 60 HRC | — |
What is 20CrMnTi Isothermal Annealed?
20CrMnTi Isothermal Annealed is 20CrMnTi heat treated to Isothermal Annealed — preferred pre-machining treatment for gear blanks: uniform ferrite–pearlite structure, low hardness scatter and better heat-treat dimensional stability. 20CrMnTi Isothermal Annealed has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi). 20CrMnTi Isothermal Annealed has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,440°C (2,624 °F). Annealed is the default condition FabDigit quotes; Isothermal Annealed is available on request or by drawing note.
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
- Forms and bends easily — 62/100, better than 78% of steel grades
20CrMnTi Isothermal Annealed properties
Typical room-temperature values for 20CrMnTi Isothermal Annealed; 22 are specific to this condition. Other listed values are 20CrMnTi reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20CrMnTi Isothermal Annealed has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,440°C (2,624 °F).
Mechanical14
20CrMnTi Isothermal Annealed has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
20CrMnTi Isothermal Annealed is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical2
20CrMnTi Isothermal Annealed has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 20CrMnTi Isothermal Annealed takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability7
20CrMnTi Isothermal Annealed's machinability is good (62/100, better than 89% of steel grades); weldability fair (45/100); formability good (62/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20CrMnTi Isothermal Annealed
Is 20CrMnTi easy to machine?
Machine in the annealed or isothermally annealed condition (≤217 HB) with carbide tooling; leave grinding stock for post-carburizing distortion, since the 58–62 HRC case can only be finished by grinding or hard turning with CBN.
Can 20CrMnTi be welded?
Poor as-welded weldability due to hardenability — preheat 200–300 °C, use low-hydrogen consumables and post-weld temper; never weld carburized surfaces.
Can 20CrMnTi be formed, bent or molded?
Good hot forgeability at 1150–850 °C and acceptable cold forging/upsetting when spheroidize-annealed; avoid tight cold bends in hot-rolled or cold-drawn bar.
What surface finishes work on 20CrMnTi?
Not anodizable; protect with oil, phosphating, black oxide, zinc or nickel plating — bake after plating to avoid hydrogen embrittlement of high-hardness cases.
20CrMnTi 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 | 0.17 – 0.23 | 0.2 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.8 – 1.1 | 0.95 |
| Cr | 1 – 1.3 | 1.15 |
| Tigrain-refining addition | 0.04 – 0.1 | 0.07 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Niresidual max | ≤ 0.3 | — |
| Curesidual max | ≤ 0.25 | — |
| Moresidual max | ≤ 0.15 | — |
| Fe | balance | — |
20CrMnTi Isothermal Annealed — frequently asked
What is 20CrMnTi Isothermal Annealed used for?
20CrMnTi Isothermal Annealed is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn-Ti bar.
What is the yield strength of 20CrMnTi Isothermal Annealed?
20CrMnTi Isothermal Annealed has a typical yield strength of 410 MPa (59.5 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 57% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 20CrMnTi Isothermal Annealed easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machine in the annealed or isothermally annealed condition (≤217 HB) with carbide tooling; leave grinding stock for post-carburizing distortion, since the 58–62 HRC case can only be finished by grinding or hard turning with CBN.
Can 20CrMnTi Isothermal Annealed be welded?
With care — weldability is rated fair (45/100). Poor as-welded weldability due to hardenability — preheat 200–300 °C, use low-hydrogen consumables and post-weld temper; never weld carburized surfaces.
What surface finishes work on 20CrMnTi Isothermal Annealed?
Not anodizable; protect with oil, phosphating, black oxide, zinc or nickel plating — bake after plating to avoid hydrogen embrittlement of high-hardness cases.
Can 20CrMnTi Isothermal Annealed be formed, bent or molded?
Good hot forgeability at 1150–850 °C and acceptable cold forging/upsetting when spheroidize-annealed; avoid tight cold bends in hot-rolled or cold-drawn bar.
What is the maximum service temperature of 20CrMnTi Isothermal Annealed?
20CrMnTi Isothermal Annealed is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 20CrMnTi Isothermal Annealed?
Yes — 20CrMnTi Isothermal Annealed is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- GB/T 3077 Alloy structural steels (2015)
- GB/T 699 / GB/T 702 bar dimensions & delivery conditions — SAC (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19: Fatigue and Fracture (carburized steels) — ASM International (1996)
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.