Weld Toughness vs Weld Strength

If you have ever been tasked with selecting the right specification and grade of steel for a particular application you know there are hundreds of choices.  Typically these are based on the materials tensile strength and yield strength.  There are many factors that go into selecting the right base metal for a given application.  In […]

7 Variables That Affect Weld Penetration

Complete joint penetration (CJP) welds will have the exact same effective weld size regardless of welding process.

Getting deeper penetration, or at least adequate penetration is very important in welding.  There are a few applications in which we wish to minimize penetration, but in general we always want good penetration.  There are many variables that affect penetration, some more than others.  It is important to know how each individual variable affects the […]

Dangers of not Maintaining Proper Interpass Temperature

Last week we had the pleasure of working with a fabricator of pressure vessels in order to help them reduce manufacturing costs.   As mandated by the ASME Boiler and Pressure Vessel Code this fabricator had welding procedure specifications (WPSs) and procedure qualification records (PQRs) in place.  These were properly written, tested and documented. The WPS […]

5 Factors that Contribute to Silicon Island Formation in Welds

The formation of silicon islands on welds made with the GMAW (mig) and MCAW (metalcore) processes is very common.  For the most part, these silicon islands are not a problem.  However, if the weld is to be painted, you better remove these islands. Otherwise, they will eventually pop off and leave an unpainted spot in […]

How to Weld Weathering (CORTEN) Steel

Corten, or COR-TEN, is the trademark name for weathering steels manufactured by U.S. Steel Corporation.  Weathering steels are a family of low carbon steel alloys that were specifically developed to provide higher strength and more importantly eliminate the need to paint to protect against the elements (rain, snow, humidity, sun, salt, etc.). A242 and A588 […]

10 Types of Welding Discontinuities Explained

Not all discontinuities are defects

Cracks can lead to catastrophic failure in a relative short amount of time.

Not all weld discontinuities are weld defects, but all weld defects are discontinuities. Understanding the difference will let you know if you need to scrap a part, repair it or simply add more weld. There are many codes depending on what type of product you are welding on. The codes are used as guidelines by […]

Should Heat Input Always Be Kept As Low As Possible?

Many ‘experts’ in the welding industry talk about high heat input as something that should always be avoided.  Unfortunately, this is not good advice.  High heat input can be detrimental in many cases, but other times we want to have higher heat input. Heat input is directly related to amperage and voltage and inversely related […]

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 […]

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 […]