Weld cracks in hardfacing by Lincoln's Weld Tech Expert, Dan Mahony  

Dan Mahony

Within the walls of The Lincoln Electric Company are some of the brightest minds in welding, but we wouldn't be The Welding Experts® if it weren't for the expertise of our customers. Learn with us from questions submitted by real customers and answered by the real experts.

I continue to get cracks in the face of my welds when I use Lincore 55. What am I doing wrong?

“Nothing,” according to Lincoln Technical Rep. Dan Mahony.

When welding two pieces of steel together, a crack in the weld is a bad thing. However, when you’re applying a hardfacing material to reduce frictional wear on a piece of steel, a crack in the face of the weld is a good thing. Selecting a welding electrode for joining is typically done by identifying the mechanical properties (tensile, yield, ductility and impact strength) of the steel you are welding, and selecting a filler material that duplicates those properties.

Hardfacing electrodes, in contrast, are very highly alloyed electrodes. This is what makes them so hard. They are designed to resist impact or abrasion, or both. Hardfacing electrodes are not designed for joining steels together. Hardfacing deposits can be so hard they surrender any, or all, ductility.

Immediately after welding the deposited hardfacing material begins to contract, or change shape, as the heat dissipates. Since most hardfacing deposits have nearly no ductility, the welds will crack. This alarms many welders. Most often these cracks are transverse (cross) cracks, which are very beneficial to relieve the residual stress in the weld bead. This type of cracking will not affect the wear resistance.

You’re doing nothing wrong.