4 Key Factors Affecting the Fatigue Life of Welded Structures

Designing for fatigue is very different than designing for static loads.  One of the biggest challenges is being able to estimate the loads, timing of the loads and duration of the loads.   If you look at a bridge you have to estimate the number of vehicles going on the bridge every day, the weight of […]

Estimating the Fatigue Life of Steel Welded Structures and Components

Using S-N curves and formulas from Clause 2 of AWS D1.1

Heat affected zone crack induced by hydrogen. The crack originates at point of high stress as hydrogen diffuses out of the weld and heat affected zone.

The majority of industrial equipment and welded structural components are subjected to repeated fluctuating loads. These loads are typically of magnitudes that are within the elastic region of the material and well below its yield strength. This means that any deformation of the structure caused by the applied stress will then return to its normal […]

5 MORE Questions You Should Know for the CWI Exam

And fundamental principles for the fabrication of steel structures

Today we’ll cover 5 more very important concepts that are governed by the AWS D1.1 Structural Welding Code (Steel). If you missed our last post with the first five questions simply click here.  These concepts can show up as questions in the Certified Welding Inspector (CWI) Exam. As stated in our article from last week, […]

5 Questions and Answers You Must Know for the CWI Exam

And fundamental principles for the fabrication of steel structures

If you have taken or hope to take the CWI exam you probably have searched for some practice exam questions.  In practicing for the code book portion of the test you may have come across a few questions for which you could find the answer, but didn’t really understand the importance of the question or […]

Importance of Macro Etch Testing of Welds

Macro etch tests are commonly done as part of qualification tests for welders and welding procedures. This test is relatively easy to do and does not require complex or expensive equipment.  However, very few fabricators ever perform this test. A macro etch test can serve as verification that a change on how something is welded […]

Understanding Why Your Welds Crack – Part 3

Location of Cracks

Cracks can be categorized by their location: weld metal, heat affected zone and unaffected (by heat) base metal.

In our previous two articles we talked about categorizing cracks based on when they occur and in which direction they propagate.  Today on our third and final article on understanding why your welds crack we look at the importance of location. If you want to review or if you missed our previous two articles simply […]

Understanding Why Your Welds Crack – Part 2

Direction of Cracks

In our previous post we discussed categorizing cracks based on when they occur.  If you missed this you can read it at Understanding Why Welds Crack: Timing. As discussed in this previous article, cracks can and should be categorized based on three criteria: Timing – did the crack occur immediately after welding (hot crack), did […]

Understanding Why Your Welds Crack – Part I

Timing of Cracks

Cracks are perhaps the only discontinuity for which there is no allowance.  Most codes require that cracks be repaired.  Crosscheck cracks on some hardfacing applications may be OK, but in general, if a weld cracks it’s a big problem. This problem is time consuming and costly in most cases. When you get a crack you don’t […]

Tips for Passing the AWS 3G FCAW Certification

Passing the AWS Structural Welder Qualification Test (vertical up certification on Flux-Cored Arc Welding) can be problematic for some, but insuring the right procedures and techniques  are used should make things a lot easier.  The good thing about this qualification is that if passed it certifies the welder no just in the 3G position, but […]

9 Maintenance Problems that Cause Bad Welds

Maintenance-related problems are responsible for a large portion of bad welds in every day welding. However, these causes go unnoticed and unresolved because they happen slowly over time. A proper preventive maintenance program for welding machines, CNC cutting tables and other industrial equipment is absolutely necessary. Many of the problems related to maintenance that cause […]