# AWS ER70S-B2L or ER49S-B2L (K20500) Weld Metal

AWS ER70S-B2L is a weld metal formulated for joining alloy steels. Cited properties are appropriate for the post-weld heat treated (PWHT) condition. ER70S-B2L is the AWS designation for this material. K20500 is the UNS number.

It has a moderately low embodied energy among alloy steel welding fillers. In addition, it has a fairly low tensile strength and a moderately low base cost.

The graph bars on the material properties cards below compare AWS ER70S-B2L 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

22 *%*

Poisson's Ratio

0.29

Shear Modulus

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

Tensile Strength: Ultimate (UTS)

590 *MPa* 85 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

450 *MPa* 65 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

260 *J/g*

Melting Completion (Liquidus)

1460 *°C* 2660 *°F*

Melting Onset (Solidus)

1420 *°C* 2580 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

40 *W/m-K* 23 *BTU/h-ft-°F*

Thermal Expansion

13 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.5 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.6 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

3.0 *% relative*

Density

7.8 *g/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

21 *MJ/kg* 9.1 *x 10 ^{3} BTU/lb*

Embodied Water

54 *L/kg* 6.4 *gal/lb*

## Common Calculations

PREN (Pitting Resistance)

3.1

Resilience: Ultimate (Unit Rupture Work)

120 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

530 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

21 *points*

Strength to Weight: Bending

20 *points*

Thermal Diffusivity

11 *mm ^{2}/s*

Thermal Shock Resistance

17 *points*

## Alloy Composition

Fe | 95.3 to 97.6 | |

Cr | 1.2 to 1.5 | |

Mn | 0.4 to 0.7 | |

Si | 0.4 to 0.7 | |

Mo | 0.4 to 0.65 | |

Cu | 0 to 0.35 | |

Ni | 0 to 0.2 | |

C | 0 to 0.050 | |

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