General Characteristics of Stainless 422
With better strength at higher temperatures, Stainless 422 is an appealing alternative to Stainless 403. It offers ductility and strength from room temperature to 1200°F (649°C) and resists scaling and oxidation to 1400°F (760°C).
Chemical Composition of Stainless 422
- Carbon 0.20-0.25
- Manganese 1.00 max
- Molybdenum 0.75-1.25
- Chromium 12.00-14.00
- Silicon 1.00 max
- Sulfur 0.03 max
- Nickel 0.40-1.00
- Tungsten 0.75-1.25
- Vanadium 0.20-0.50
- Phosphorus 0.04 max
- Iron balance
Heat Treatment of Stainless 422
- To anneal, heat to 1600° to 1650°F (871° to 899°C), then slowly cool in furnace
- For stress relief, heat to 1100° to 1150°F (593° to 621°C) before furnace or air cooling
- Harden by heating to 1875° to 1925°F (1024° to 1052°C) before oil quenching and tempering
Applications of Stainless 422
- Aircraft parts
- Steam and gas turbine components
- High heat components
Machinability of Stainless 422
- Comparable to 18-8 but easier to machine
- Help avoid galling with sharply ground tools
- Maintain consistent speed and feed
- Turning tools: 8-14° side rake
- Drilling: 140° point
- Threading: grind tools with 10-15° back rake
- Cobalt high-speed tools: turn at 90-120 sfpm, drill at 40-75 sfpm, mill at 70-120 sfpm, ream at 20-60 sfpm, roughing and finishing at 200-400 sfpm
Workability of Stainless 422
- Initial forging and rolling at 2100° to 2150°F (1149° to 1177°C)
- 1700°F (927°C) minimum to hot work