422 Stainless Steel

422 stainless steel (UNS S42200) is a hardenable martensitic stainless steel engineered for reliable performance where strength and toughness are required, especially at elevated temperatures. Compared to 420 stainless steel, it offers enhanced high-temperature capabilities, making it a solid choice for demanding applications. 

1. Chemical Composition

2. Key Properties and Performance

422 stainless steel exhibits a combination of physical and mechanical properties, making it suitable for challenging environments. Note that mechanical properties are highly dependent on the specific heat treatment applied.

2.1 Physical Properties (Typical Annealed Condition)

• Density: 28 lb/in.³ (7.75 g/cm³)
• Modulus of Elasticity: 8 x 10⁶ psi (205 GPa)
• Thermal Conductivity: Increases moderately with temperature (e.g., approx. 13.8 Btu/h·ft·°F at 212°F / 23.9 W/m·K at 100°C).
• Specific Heat: Relatively consistent within typical operating ranges (approx. 0.11 Btu/lb·°F / 0.46 kJ/kg·K).

2.2 Mechanical Properties (Condition Dependent)

The strength, hardness, and ductility of 422 stainless steel can be tailored through heat treatment. Common examples include:

• Annealed Condition: Generally provides tensile strengths in the range of 88-140 ksi (607-965 MPa) with good ductility (elongation often 13% or higher). Hardness is typically below HRC 22 (approx. B98 or 248 HB).
• Hardened and Tempered Condition: Can achieve significantly higher strength (e.g., Tensile Strength ~180 ksi / 1241 MPa, Yield Strength ~140 ksi / 965 MPa) and hardness (e.g., ~HRC 38) after appropriate hardening and tempering (e.g., tempering around 1000°F/593°C). Elongation is lower in this condition (e.g., ~5%). Higher strength levels are achievable with specific heat treatments.