# ASTM A372 Grade D Carbon Steel

ASTM A372 grade D steel is a carbon (non-alloy) steel formulated for primary forming into wrought products. Cited properties are appropriate for the normalized condition. ASTM A372 Grade D is the ASTM designation for this material. Older literature may refer to this material as Type IV, but this is now discouraged.

It has a moderately high embodied energy among wrought carbon or non-alloy steels. In addition, it has a very high tensile strength and a moderately low ductility.

The graph bars on the material properties cards below compare ASTM A372 grade D steel to: wrought carbon or non-alloy 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

250

Elastic (Young's, Tensile) Modulus

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

Elongation at Break

17 *%*

Fatigue Strength

340 *MPa* 49 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

500 *MPa* 72 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

810 *MPa* 120 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

510 *MPa* 74 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

250 *J/g*

Maximum Temperature: Mechanical

400 *°C* 750 *°F*

Melting Completion (Liquidus)

1460 *°C* 2650 *°F*

Melting Onset (Solidus)

1420 *°C* 2580 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

51 *W/m-K* 29 *BTU/h-ft-°F*

Thermal Expansion

12 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.2 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.3 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

2.1 *% relative*

Density

7.8 *g/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

20 *MJ/kg* 8.4 *x 10 ^{3} BTU/lb*

Embodied Water

48 *L/kg* 5.8 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

120 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

700 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

29 *points*

Strength to Weight: Bending

25 *points*

Thermal Diffusivity

14 *mm ^{2}/s*

Thermal Shock Resistance

26 *points*

## Alloy Composition

Fe | 97.1 to 97.9 | |

Mn | 1.4 to 1.8 | |

C | 0.4 to 0.5 | |

Si | 0.15 to 0.35 | |

Mo | 0.17 to 0.27 | |

P | 0 to 0.015 | |

S | 0 to 0.010 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM A372: Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels

Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004

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

Carbon Steel Handbook, D. Gandy, 2007

ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996

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