# Hardened 420 Stainless Steel

Hardened AISI 420 is AISI 420 stainless steel in the hardened (H) condition. The graph bars on the material properties cards below compare hardened AISI 420 to: wrought martensitic stainless steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

## Mechanical Properties

Brinell Hardness

190

Elastic (Young's, Tensile) Modulus

190 *GPa* 28 *x 10 ^{6} psi*

Elongation at Break

8.0 *%*

Fatigue Strength

670 *MPa* 97 *x 10 ^{3} psi*

Poisson's Ratio

0.28

Rockwell B Hardness

84

Shear Modulus

76 *GPa* 11 *x 10 ^{6} psi*

Shear Strength

1010 *MPa* 150 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

1720 *MPa* 250 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

1310 *MPa* 190 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

280 *J/g*

Maximum Temperature: Corrosion

390 *°C* 730 *°F*

Maximum Temperature: Mechanical

620 *°C* 1150 *°F*

Melting Completion (Liquidus)

1510 *°C* 2750 *°F*

Melting Onset (Solidus)

1450 *°C* 2640 *°F*

Specific Heat Capacity

480 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

27 *W/m-K* 16 *BTU/h-ft-°F*

Thermal Expansion

10 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

3.0 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

3.5 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

7.5 *% relative*

Density

7.7 *g/cm ^{3}* 480

*lb/ft*

^{3}Embodied Carbon

2.0 *kg CO _{2}/kg material*

Embodied Energy

28 *MJ/kg* 12 *x 10 ^{3} BTU/lb*

Embodied Water

100 *L/kg* 12 *gal/lb*

## Common Calculations

PREN (Pitting Resistance)

14

Resilience: Ultimate (Unit Rupture Work)

130 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

4410 *kJ/m ^{3}*

Stiffness to Weight: Axial

14 *points*

Stiffness to Weight: Bending

25 *points*

Strength to Weight: Axial

62 *points*

Strength to Weight: Bending

41 *points*

Thermal Diffusivity

7.3 *mm ^{2}/s*

Thermal Shock Resistance

62 *points*

## Alloy Composition

Fe | 82.3 to 87.9 | |

Cr | 12 to 14 | |

Mn | 0 to 1.0 | |

Si | 0 to 1.0 | |

Ni | 0 to 0.75 | |

C | 0.15 to 0.4 | |

Mo | 0 to 0.5 | |

P | 0 to 0.040 | |

S | 0 to 0.030 |

All values are % weight. Ranges represent what is permitted under applicable standards.

## Followup Questions

## Further Reading

ASTM A176: Standard Specification for Stainless and Heat-Resisting Chromium Steel Plate, Sheet, and Strip

ASTM A276: Standard Specification for Stainless Steel Bars and Shapes

Advanced Materials in Automotive Engineering, Jason Rowe (editor), 2012

Welding Metallurgy of Stainless Steels, Erich Folkhard et al., 2012

ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels

Corrosion of Stainless Steels, A. John Sedriks, 1996

ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994

Advances in Stainless Steels, Baldev Raj et al. (editors), 2010