A-21 (AMS PENDING)
A-21 an advanced martensitic stainless steel produced via vacuum induction melt and vacuum arc remelting processes. Known for its high strength and toughness, A-21 is often used in structural applications where corrosion, fatigue, and temper resistance are required–particularly useful for applications spanning industries such as aerospace, defense, energy, industrial, and transportation.
MELT PRACTICE: | VIM-VAR |
SPECIFICATIONS: |
AMS PENDING
|
ABOUT A-21
A-21 provides high performance stainless properties in the carburized, nitrided, and quenched and tempered conditions. As the world’s only stainless carburizing steel that remains stainless in the areas it is carburized, A-21 provides a deep, hard, stainless case with a strong, tough, and ductile core, and is often considered the stainless version of 9310 or 8620. In the ferritic carbo-nitrided condition, A-21 retains its stainless properties and boasts very high surface hardness, while nitriding is typically performed on finished parts with minimal distortion.
GET A-21 AT SULLIVAN STEEL
Grade | Type | Size |
A-21 | VIM-VAR | 1.125" - 7.000" |
Chemical Composition – VIM-VAR
C | Mn | Si | Cr | Ni | Mo | V | Mn |
0.13% max | 0.75% max | 1.00% max | 10.50-14.00% | 2.00-3.00% | 0.40-0.80% | 0.25% max | 0.75% max |
HEAT TREATMENT
ANNEALING: 1,100 - 1,200°F (593 - 649°C)
HARDENING: 1,550 - 1,600°F (843 - 871°C)
NORMALIZING: 1,600 - 1,650°F (871 - 899°C)
TEMPERING: 200 - 1,200°F (93 - 649°C)
MECHANICAL PROPERTY DATA
Spec | Tensile KSI | Tensile MPa | Yield KSI | Yield MPa | Elongation % | R of A | HBW |
QT160 | 160 | 1103 | 150 | 1034 | 16 | 50 | 33-38 |
QT130 | 130 | 896 | 125 | 862 | 18 | 60 | 29-34 |
C190 | 190 | 1310 | 145 | 1000 | 12-14 | 40-45 | 39 |
C170 | 170 | 1172 | 135 | 1034 | 12-14 | 40-45 | 35 |
QT160/130 = quenched & tempered and nitrided applications
C190/170 = carburized applications (VAR and VIMVAR)
CORROSION RESISTANCE
A-21 outperforms conventional stainless steel, CPM S90V, P675, and BG-42 in salt fog corrosion tests in the carburized and heat treated condition. It also performed exceptionally well in humidity, salt spray, and stress corrosion cracking tests, and had moderate performance in sour oil/gas tests.
Corrosion Test | Average Corrosion Rate |
ASTM B117 (Salt Fog) Quenched and tempered, salt bath nitrided |
None |
ASTM D1735 (Humidity) Carburized, salt bath nitrided |
None |
ISO 15156 (Sulfide Stress Cracking) Room temperature |
No failure |
ASTM G129 (Stress Corrosion Cracking) Room temperature |
None |
APPLICATIONS
- Carburized bearings, gears, actuators, splines, shafts, races
- Carburized bolts, gun barrels, bolt carriers, firing pins
- Drilling and workover rotors, housings, frack pumps, valve pumps
- Valve seats and trims, ball screws
PURCHASE A-21 STEEL
Sullivan Steel stocks A-21 in 1.125” to 7.000”. Want to learn more about A-21 and how it might fit into your application? We are here to provide guidance and technical support for your project–just speak to one of our experts.
Already know your requirements and just want to purchase A-21? Request a quote now!