WELD FAILURE ANALYSIS: A PRACTICAL STEP-BY-STEP METHOD

When something breaks, most people jump straight to blaming the weld. Sometimes it was the weld. Sometimes it was the design, the loading, or the base metal. A basic failure analysis process helps you stop guessing and start fixing the real problem. This matters for everything from trailer repairs to structural brackets and equipment frames around Edmonton.

The goal of failure analysis

The goal is not to assign blame. The goal is to find the root cause and prevent a repeat failure. A repair that ignores the cause is just a temporary band-aid. If the part is overloaded, a perfect weld will still break.

Step 1: Preserve the evidence

Do not grind, sand, or torch the fracture surfaces if you want answers. The fracture face holds clues. If you must make the area safe, take photos first. Keep broken pieces together, and note how they were positioned.

Step 2: Document the situation

Good notes beat perfect memory. Record:

• What failed and where it was used
• When it failed and under what conditions
• Any recent changes: new loads, impacts, modifications
• Environment: outdoor exposure, corrosion, winter use, vibration

In Edmonton, winter adds a common factor: cold steel is less forgiving, and corrosion from road salt can accelerate cracking at weak points.

Step 3: Visual inspection (the fastest win)

Most failures leave obvious signs if you look closely:

• Undercut at the toe: a groove beside the weld that can act like a crack starter.
• Porosity: pinholes or cavities, often from contamination or shielding problems.
• Lack of fusion: weld metal sitting on the surface without bonding properly.
• Crack path: did it crack through the weld, beside it, or in the base metal?

Step 4: Identify the failure mode

This is where you separate a one-time overload from a progressive fatigue failure.

Step 5: Check design and load path

Many weld failures are design failures. A small weld on a high-stress corner will crack no matter who welded it. Look for:

• Welds placed in bending instead of shear
• Sharp corners and stress concentrators
• Attachments welded to thin material without reinforcement
• Loads that changed over time (heavier equipment, higher vibration)

Step 6: Verify materials and procedure

Wrong filler metal, wrong process, or wrong technique can contribute to failure. That includes welding over paint, rust, or galvanized coating without proper prep, or using a process that cannot handle the environment (for example, shielding gas issues in wind).

Step 7: Plan the repair to prevent a repeat

A good repair often includes more than rewelding the same crack:

• Remove the crack fully: gouge or grind to sound metal.
• Improve the joint: better bevel, better fit-up, correct reinforcement.
• Reduce stress: add a gusset, change attachment geometry, spread load.
• Protect against corrosion: prep and coat the repaired area properly.

Need a repair you can trust?

YEGWELD does mobile welding repairs and fabrication in Edmonton and surrounding areas. If you have a failed weld, we can assess the cause and recommend a fix that holds up. Call 780-233-8285 or use our contact page.

This article is for informational purposes only and may contain inaccuracies. Always consult a certified welding professional before starting any project.