How to Use Prequalified WPSs for Stainless Steel in Accordance with AWS D1.6

AWS D1.6 is the Structural Welding Code for Stainless Steel.  Its primary concern is with the structural integrity of weldments and not with resistance to corrosion, creep or sensitization.  As a matter of fact, the word “corrosion” appears only eight times in the 9 clauses of AWS D1.6.  Requirements for these concerns are the responsibility […]

14 Welding Procedure Specification Variables

A Welding Procedure Specification has several variables which should be carefully specified.  The values selected for the variables discussed below have a significant impact on weld soundness and mechanical properties. It is critical that these values be appropriate for the specific requirements of applicable code and job specifications.  Some of the most important variables in […]

Rainbow Colors in Stainless Steel Welding

Are they good or bad?

Different joints will have different levels of admixture (the mixing of weld metal with base metal) . The higher the admixture the more silicon islands will form on the surface of the weld.

We receive several calls about welding stainless and the beautiful rainbow colors, or lack thereof, on the weld and heat affected zone.  Is the tinting an indication of quality?  Are these colors acceptable? Do they show that the weld had enough heat to penetrate?  Why do they need to be cleaned?  The questions are endless. […]

Importance of Macro Etch Testing of Welds

Lack of fusion cannot be detected visually. The image above shows a macroetch of a fillet weld showing that lack of root fusion.

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 […]

How to Weld Titanium

Titanium is a metal which is silvery gray in color and has about half the density of steel (0.163 lb/in3).  Pure titanium is relatively soft has very low ultimate tensile strength.   For use in structural applications titanium is alloyed with chromium and iron, chromium and aluminum, manganese and aluminum and manganese alone.  These alloying elements […]

Effects of Shielding Gases in GMAW

Using the right shielding gas is essential not only to prevent porosity but to get proper penetration, the mechanical properties you desire including weld strength, and overall weld quality.  In order to select the right shielding gas you need to consider the following: –          Alloy of filler metal –          Material thickness –          Mode of GMAW […]