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. […]

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 […]

Weldability of Annealed, Normalized, Quenched and Tempered Steels

We frequently receive requests for help developing welding procedures for welding on quenched and/or quenched and tempered steels.  Sometimes the call for help is to determine why these steels cracked after welding and how to prevent it from happening in the future. Understanding the supplied condition of the steel you are going to be welding […]

Welding Hot Rolled vs Cold Rolled Steel

Both hot rolled and cold rolled steels can easily be welded.  However, there are differences between the two that will impact which you choose to use.  Making this choice depends on several factors such as strength, surface finish, dimensional accuracy and cost.   To understand the difference between hot rolled and cold rolled steel and how […]

The Reason Behind AWS D1.1 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:2020 Structural Welding Code (Steel) you can find this on Table 7.7.   If you happen to own a copy of AISC 360-16 Specification for Structural […]

6 Factors That Lead to Cracks in Aluminum Welds

Welding aluminum should not be complicated.  That is, if you are welding 6061-T6 (very common) with ER5356 or ER4043 filler metal.   Although this alloy is still susceptible to cracking, other aluminum alloys are much more prone to cracking. Below are 6 factors that affect cracking susceptibility when welding aluminum alloys.  Thermal stresses: Aluminum has […]

How Carbon Content Affects the Weldability of Steels

And its effects on strength, hardness, ductility and machinability

Steel is an alloy of iron and carbon along with several other elements in small quantities, all of which have an impact on its properties. Steels can contain varying amounts of carbon and are typically categorized as low, medium or high carbon steels. Low carbon steels are those containing 0.30% carbon or less.  Medium carbon […]

6 Reasons Why Metal Fabricators Must Understand Metallurgy

Metal fabricators, or at least those in charge of welding operations, must have a sound understanding of metallurgy.  Metallurgy is the study of metals, their properties and their behaviors, especially when undergoing the welding process.  Below are 6 areas of fabrication for which an understanding of the metallurgical properties of metals is vital. Material Selection […]

Understanding Certificates of Conformance for Filler Metals

Manufacturers of welding consumables are required to provide certificates of conformance for all of their welding filler metals.  These certificates confirm that their consumables conform to the chemical and mechanical requirements determined by the American Welding Society for that specific filler metal.  Manufacturers are not required to test every single batch of product that they […]