# SAE-AISI 6118 (G61180) Chromium-Vanadium Steel

SAE-AISI 6118 steel is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 6118 is the designation in both the SAE and AISI systems for this material. G61180 is the UNS number.

It has a moderately low tensile strength and a moderately high embodied energy among SAE-AISI wrought steels.

The graph bars on the material properties cards below compare SAE-AISI 6118 steel to: SAE-AISI wrought 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

140

Elastic (Young's, Tensile) Modulus

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

Elongation at Break

23 *%*

Fatigue Strength

210 *MPa* 30 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

300 *MPa* 43 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

470 *MPa* 69 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

290 *MPa* 42 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

250 *J/g*

Maximum Temperature: Mechanical

410 *°C* 770 *°F*

Melting Completion (Liquidus)

1460 *°C* 2660 *°F*

Melting Onset (Solidus)

1420 *°C* 2590 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

45 *W/m-K* 26 *BTU/h-ft-°F*

Thermal Expansion

13 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.1 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.2 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

2.1 *% relative*

Density

7.8 *g/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

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

Embodied Water

49 *L/kg* 5.8 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

93 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

220 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

17 *points*

Strength to Weight: Bending

17 *points*

Thermal Diffusivity

12 *mm ^{2}/s*

Thermal Shock Resistance

14 *points*

## Alloy Composition

Among alloy steels, the composition of SAE-AISI 6118 steel is notable for including vanadium (V). Vanadium has a strong hardening effect, but this effect is particularly sensitive to the type of tempering.

Fe | 97.8 to 98.6 | |

Mn | 0.5 to 0.7 | |

Cr | 0.5 to 0.7 | |

Si | 0.15 to 0.35 | |

C | 0.16 to 0.21 | |

V | 0.1 to 0.15 | |

S | 0 to 0.040 | |

P | 0 to 0.035 |

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

## Followup Questions

## Similar Alloys

## Further Reading

ASTM A752: Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Alloy Steel

ASTM A322: Standard Specification for Steel Bars, Alloy, Standard Grades

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

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

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