Preheat is used when a base material, due to its chemical composition, thickness or level or restraint, is susceptible to cold cracking (hydrogen induced cracking). Knowing what temperature to preheat your base metal is sometimes a complicated matter. You may hear people say “preheat to 300F to be safe.” The reality is that 300F may […]
Most types of stainless steels have good weldability and can be welded with all arc welding processes (GMAW, FCAW, GTAW, SMAW and SAW). Stainless is used in many different applications for its strength, abrasion resistance and corrosion resistance. Unfortunately, many assume it can be welded just like carbon steel. In fact, this is the first […]
Bigger is not always better, at least not in welding. Making welds bigger than they need to be is not only wasteful and costly, but can cause other problems such as distortion and premature failure. Below are 3 reasons why you may need to pay close attention to your weld sizes. 1. Bigger welds cost […]
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. […]
Today we’ll cover 5 more very important concepts that are governed by the AWS D1.1 Structural Welding Code (Steel). If you missed our last post with the first five questions simply click here. These concepts can show up as questions in the Certified Welding Inspector (CWI) Exam. As stated in our article from last week, […]
If you have taken or hope to take the CWI exam you probably have searched for some practice exam questions. In practicing for the code book portion of the test you may have come across a few questions for which you could find the answer, but didn’t really understand the importance of the question or […]
If you are a CWI, welding engineer or serve in a capacity that requires you to use and interpret welding codes, you probably have run into instances where the code is not very clear. Many of the questions we receive from our readers deal with interpreting codes and standards. Many times it is not about […]
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 […]
Welding engineering is a complex field that requires expertise in many different engineering disciplines. The welding engineer must take advanced courses in metallurgy (including welding metallurgy), material science, mechanics of materials, thermodynamics, chemistry and fundamentals of all welding processes. Welding engineers are tasked with many different activities which include but are not limited to: […]
Heat input is important because it has an effect on cooling rates which in turn can significantly affect the mechanical properties of the weld and heat affected zone. It also plays a role in susceptibility to distortion. High heat input can be beneficial in some cases and detrimental in others. A common misconception is that […]
