Causes of Porosity in Submerged Arc Welds

Submerged arc welding is typically done automatically, meaning it is not done by hand but rather it is set up as hard automation.  The operator simply controls the welding machine and torch position to obtain the desired results.  Typically the system is run by an operator and not a welder.  So when problems arise the […]

Common Tests for Welder Performance Qualification

The purpose of welder performance qualifications is to ensure that the welder can deposit sound welds.  There are several tests, both destructive and nondestructive, that are used to evaluate a welder’s ability to deposit good welds.  Below are four of the most common test applied for these qualifications:   Visual Inspection (VT) Visual inspection is […]

What is Stress Relieving and Why We Need It

Stress relieving is a form of post weld heat treatment. In stress relieving we heat a material to a specific temperature; hold it at this temperature for a specified amount of time in order to reduce or eliminate residual stresses; and then cool it at a slow enough rate to prevent these stresses from redeveloping. […]

Is Weld Strength Affected by Shielding Gas Mix?

Can our selection of shielding gas affect the strength of a weld and other important mechanical properties?  Absolutely!  The difference is more pronounced when using flux-cored (FCAW) wires than when using mig (GMAW) wires, especially as the wire’s tensile strength goes up.   Although we can affect strength by using different gases, what we should be […]

Pick Your Prequalified Welding Procedures Carefully

If you work with AWS D1.1 you are probably familiar with the use of prequalified welding procedures.  The use of prequalified WPSs provides many benefits to the fabricator, one of which is costs savings due being exempt from having to perform costly testing to qualify the welding procedure.  However, if you are looking to save […]

Welding Cost Reduction Revisited

Many of our customers realize that there is a great potential for reducing costs in welding operations.  Yet, not many are willing to attack this area of manufacturing.  The reason for this is that welding is a very complicated industrial process.  It has many variables that come into play which determine quality and productivity.  So […]

Fillet Weld Leg Sizes Are Meaningless!

Measuring fillet weld legs is meaningless, well… not really.  Fillet weld leg sizes are very important, but simply measuring the leg of a fillet weld does not tell us if we actually achieved the desired throat dimension.  The strength of a fillet weld is determined by its effective throat.  As you can see in the […]

Importance of Weld Failure Analysis

Basic guidelines to troubleshoot weld failures

When a weld fails we don’t always know what caused it.  We may try something different and if it doesn’t fail the next time we adopt that as the new standard.  However, it is very important to know the root cause of weld failures.  If we don’t know what caused the failure how can we […]

What is Post Weld Heat Treatment (PWHT)?

What is it? Why is PWHT needed? How is PWHT done?

Have you heard of post weld heat treatment (PWHT)? Of course you have. If you are involved in welding you have definitely heard this term.  But what is PHWT? When is PWHT required?  What temperature should PWHT be done at?  Heat treating of materials can be a very complicated subject, but when it comes to […]