The Importance of the Heat Affected Zone (HAZ)

When we weld we generate enough heat in the welding arc to melt the filler metal and base material.  Or just the base material is we are welding autogenously (as in GTAW without filler).  The edges of the base material melt and combine with the filler metal to create what is called the composite zone.  […]

21 Changes to PQR Essential Variables that Require WPS Requalification

​Have you ever seen a welding procedure specification with established amperage ranging from 200 to 550 amps?Or voltage ranging from 21 to 29 volts?Or some other variable with a huge window?This is all too common, but extremely dangerous. Why? Because changes to essential variables beyond that which is reasonable will affect the physical and mechanical […]

The Reason Behind Minimum Fillet Weld Sizes

It's not what you think

Have you ever noticed that there are design rules that prohibit sizing a fillet weld below a certain size for a given thickness of material? If you look at AWS D1.1/D1.1M:2015 Structural Welding Code (Steel) you can find this on Table 5.7.   If you happen to own a copy of AISC 360-16 Specification for Structural […]

The Importance of Accurate Documents to Support Welder Qualifications

When it comes to precision welding and fabrication, it only takes one wrong document to cause a major problem.  Still, many companies operate by the motto: “if it ain’t broke, don’t fix it”.  Assuming you have incredible attention to detail and a lot of luck, that approach might work for a while.  That’s why companies […]

How to Keep Welder Qualifications Active

There is a misconception that welder qualifications are only good for six months.   This is not accurate.  Most codes state that welder qualifications may lapse if the welder is not engaged in a given process for which he or she is qualified for a period exceeding six months. This means that as long as the […]

How to Avoid Sensitization When Welding Austenitic Stainless Steels

Stainless steels are iron based alloys that contain a minimum of 10.5% chromium.  This chromium reacts with the air and forms a very thin but very tenacious chromium oxide layer which is what prevents stainless from rusting. There are 5 types of stainless steels which are categorized depending on additional alloying elements.  One thing they […]

Modes of Metal Transfer: Pulse

Pulsed spray refers to a GMAW mode of transfer in which metal droplets are transferred through the arc with changes in amperage produced by the power source.  The power source provides a pulsing peak current that raises the amperage above the transition current and allows for axial spray transfer.  This peak current is only applied […]

Modes of Metal Transfer: Spray

Spray is a mode of metal transfer in which a fine spray of metal droplets are projected axially from the tip of the electrode to the work.  These droplets are smaller in diameter than the electrode.  This mode of transfer is characterized by high wire feed speeds (high amperage), high voltage and consequently high heat […]

Modes of Metal Transfer: Globular

In our last post we explained short circuit transfer; if you missed it you can go back and read Modes of Metal Transfer: Short Circuit.  In this post we’ll spend some time going over globular transfer by covering its basics as well as its advantages and limitations. Globular transfer occurs in GMAW and MCAW processes […]

Modes of Metal Transfer: Short Circuit

The modes of metal transfer refer to the different ways in which the filler metal (electrode) is transferred through the welding arc and into the weld puddle.  We can write a book on this topic but we’ll keep it simple to provide an understanding of the different modes of transfer, what they require and what […]