# ASTM A204 Grade B Molybdenum Steel

ASTM A204 grade B is a type of ASTM A204 steel. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. The graph bars on the material properties cards below compare ASTM A204 grade B to: wrought alloy steels in the same category (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

170

Elastic (Young's, Tensile) Modulus

190 *GPa* 27 *x 10 ^{6} psi*

Elongation at Break

19 *%*

Fatigue Strength

210 *MPa* 31 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

340 *MPa* 50 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

550 *MPa* 80 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

310 *MPa* 45 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

250 *J/g*

Maximum Temperature: Mechanical

410 *°C* 760 *°F*

Melting Completion (Liquidus)

1470 *°C* 2670 *°F*

Melting Onset (Solidus)

1430 *°C* 2600 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

52 *W/m-K* 30 *BTU/h-ft-°F*

Thermal Expansion

13 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.2 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.2 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

2.4 *% relative*

Density

7.9 *g/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

20 *MJ/kg* 8.6 *x 10 ^{3} BTU/lb*

Embodied Water

47 *L/kg* 5.6 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

90 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

260 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

20 *points*

Strength to Weight: Bending

19 *points*

Thermal Diffusivity

14 *mm ^{2}/s*

Thermal Shock Resistance

16 *points*

## Alloy Composition

Fe | 97.6 to 99.46 | |

Mo | 0.41 to 0.64 | |

Mn | 0 to 1.0 | |

Si | 0.13 to 0.45 | |

C | 0 to 0.27 | |

P | 0 to 0.035 | |

S | 0 to 0.035 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM A204: Standard Specification for Pressure Vessel Plates, Alloy Steel, Molybdenum

Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011

Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005

Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008

Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015