# AWS ER80S-Ni3 or ER55S-Ni3 (K31240) Weld Metal

AWS ER80S-Ni3 is a weld metal formulated for joining alloy steels. Cited properties are appropriate for the post-weld heat treated (PWHT) condition. ER80S-Ni3 is the AWS designation for this material. K31240 is the UNS number.

It has a moderately high ductility among alloy steel welding fillers. In addition, it has a fairly high thermal conductivity and a moderately low electrical conductivity.

The graph bars on the material properties cards below compare AWS ER80S-Ni3 to: alloy steel welding fillers (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

Elastic (Young's, Tensile) Modulus

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

Elongation at Break

27 *%*

Poisson's Ratio

0.29

Shear Modulus

72 *GPa* 10 *x 10 ^{6} psi*

Tensile Strength: Ultimate (UTS)

630 *MPa* 91 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

530 *MPa* 76 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

260 *J/g*

Melting Completion (Liquidus)

1450 *°C* 2640 *°F*

Melting Onset (Solidus)

1410 *°C* 2570 *°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

13 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.4 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.5 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

4.0 *% 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* 9.8 *x 10 ^{3} BTU/lb*

Embodied Water

52 *L/kg* 6.3 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

160 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

740 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

22 *points*

Strength to Weight: Bending

21 *points*

Thermal Diffusivity

14 *mm ^{2}/s*

Thermal Shock Resistance

19 *points*

## Alloy Composition

Fe | 93.2 to 96.6 | |

Ni | 3.0 to 3.8 | |

Mn | 0 to 1.3 | |

Si | 0.4 to 0.8 | |

Cu | 0 to 0.35 | |

C | 0 to 0.12 | |

P | 0 to 0.025 | |

S | 0 to 0.025 | |

res. | 0 to 0.5 |

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

## Followup Questions

## Similar Alloys

## Further Reading

AWS A5.28: Specification for Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding

Welding Metallurgy, 2nd ed., Sindo Kou, 2003