Steel 8822 QT-28-32
Hardness band
AISI/SAE 8822 · UNS G88220
QT-28-32 = q&T 28–32 HRC
Direct-quenched-and-tempered bar or the target core condition of large carburized gears needing high core strength with good toughness.
Values for the QT-28-32 condition
Other 8822 tempers and conditions
8822 is listed in 7 conditions; see the grade overview at 8822.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard stock condition for gear blanks: softest, best machinability and most uniform response to subsequent carburizing. | 415 | 620 | 22 | 187 HB | — |
Hot rolled | Cheapest mill condition for parts that will be rough-machined then carburized; hardness and structure vary with section size. | 450 | 700 | 20 | 15 HRC | 7.8 % IACS |
Normalized | Grain refinement and structure homogenization before rough machining/carburizing; higher strength than annealed with fair machinability. | 480 | 750 | 20 | 17 HRC | 7.8 % IACS |
Cold drawn | Close-tolerance bright bar for small shafts and pins machined with light stock removal before case hardening. | 570 | 720 | 14 | 16 HRC | 7.8 % IACS |
QT-28-32This page Q&T 28–32 HRC | Direct-quenched-and-tempered bar or the target core condition of large carburized gears needing high core strength with good toughness. | 800 | 960 | 16 | 30 HRC | — |
Q&T 32–36 HRC | Chosen when heavy-duty gear or shaft cores must resist bending and case crushing; toughness margin is lower than 28–32 HRC. | 960 | 1,110 | 14 | 34 HRC | — |
Carburized, hardened & tempered | The service condition for gears and splines: hard wear/pitting-resistant case over a strong Ni-Cr-Mo core; requires finish grinding. | 1,000 | 1,250 | 10 | 60 HRC | — |
What is 8822 QT-28-32?
8822 QT-28-32 is 8822 heat treated to QT-28-32 — direct-quenched-and-tempered bar or the target core condition of large carburized gears needing high core strength with good toughness. 8822 QT-28-32 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 960 MPa (139 ksi) — stronger than 86% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi). 8822 QT-28-32 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). A is the default condition FabDigit quotes; QT-28-32 is available on request or by drawing note.
Advantages
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
8822 QT-28-32 properties
Typical room-temperature values for 8822 QT-28-32; 13 are specific to this condition. Other listed values are 8822 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
8822 QT-28-32 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).
Mechanical13
8822 QT-28-32 has a yield strength of 800 MPa (116 ksi) and a tensile strength of 960 MPa (139 ksi) — stronger than 86% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
8822 QT-28-32 is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
8822 QT-28-32 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 8822 QT-28-32 takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
8822 QT-28-32's machinability is fair (42/100, worse than 73% of steel grades); weldability fair (40/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 8822 QT-28-32
Is 8822 easy to machine?
Machine in the annealed/normalized state with carbide tooling and rigid setups (≈60 % of 1212); finish-grind after carburizing since the 58–62 HRC case is not turnable.
Can 8822 be welded?
Weldable only before carburizing with low-hydrogen consumables, 200–300 °C preheat and post-weld stress relief; welding hardened case leads to cracking.
Can 8822 be formed, bent or molded?
Hot forge 1100–1200 °C and normalize afterwards; cold forming limited to mild upsetting on annealed bar.
What surface finishes work on 8822?
Protect with oil, black oxide, Mn-phosphate or Zn/Zn-Ni plating (bake for hydrogen relief); shot peening after grinding raises gear bending fatigue.
8822 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 |
|---|---|---|
| CSAE J404 / ASTM A29 | 0.2 – 0.25 | 0.22 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Ni | 0.4 – 0.7 | 0.55 |
| Cr | 0.4 – 0.6 | 0.5 |
| Mohighest Mo of the 88xx series | 0.3 – 0.4 | 0.35 |
| P | ≤ 0.04 | — |
| Smax; H-grades and 8822H per SAE J1268 | ≤ 0.04 | — |
| Fe | balance | — |
8822 QT-28-32 — frequently asked
What is 8822 QT-28-32 used for?
8822 QT-28-32 is typically used for heavy truck transmission gears, power transmission gears, final-drive ring and pinion gears, axle shafts, bearing races and large splined shafts. In short: high core strength gear steel; deep case hardenability; higher alloy than 8720.
What is the yield strength of 8822 QT-28-32?
8822 QT-28-32 has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 960 MPa (139 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 8822 QT-28-32 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in the annealed/normalized state with carbide tooling and rigid setups (≈60 % of 1212); finish-grind after carburizing since the 58–62 HRC case is not turnable.
Can 8822 QT-28-32 be welded?
With care — weldability is rated fair (40/100). Weldable only before carburizing with low-hydrogen consumables, 200–300 °C preheat and post-weld stress relief; welding hardened case leads to cracking.
What surface finishes work on 8822 QT-28-32?
Protect with oil, black oxide, Mn-phosphate or Zn/Zn-Ni plating (bake for hydrogen relief); shot peening after grinding raises gear bending fatigue.
Can 8822 QT-28-32 be formed, bent or molded?
Hot forge 1100–1200 °C and normalize afterwards; cold forming limited to mild upsetting on annealed bar.
What is the maximum service temperature of 8822 QT-28-32?
8822 QT-28-32 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 8822-A and 8822 CARB?
A is the default condition — standard stock condition for gear blanks: softest, best machinability and most uniform response to subsequent carburizing. CARB: the service condition for gears and splines: hard wear/pitting-resistant case over a strong Ni-Cr-Mo core; requires finish grinding. Yield strength is 415 MPa in A versus 1,000 MPa in CARB.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A — Steel Heat Treating Fundamentals and Processes (carburizing) — ASM International (2013)
- Machining Data Handbook — Metcut Research Associates (1980)
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.