Our previous article discussed the importance of having a specification for weld quality. In this article we’re talking about the importance of one of its basic components: Welding Procedure Specifications (WPSs). Many fabricators don’t have WPSs. They rely in the experience of their welders to select the right parameters. As much as we want every […]
If you have been reading our articles for some time you know how strongly we feel about having documented welding procedure specifications which have been qualified by testing or prequalified in conformance with code requirements. Yet when we recommend that these very important documents be developed and used in production we get a lot of […]
It is often incorrectly assumed that quenched and tempered (Q&T) steels are hard to weld or even completely unweldable. This assumption is inaccurate as most Q&T steels have great weldability. However, extreme care must be taken to prevent cracking or loss of certain mechanical properties. A very common quenched and tempered steel is ASTM A514. […]
Interpass temperature is the temperature of the base metal in and adjacent to the weld joint prior to depositing and additional pass (weld). Maintaining and measuring interpass temperature should be done carefully. Different materials require different levels of preheat and interpass temperature. For this reason it is extremely important that both prehat and interpass temperature be specified […]
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 […]
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 […]
We receive several calls about welding stainless and the beautiful rainbow colors, or lack thereof, on the weld and heat affected zone. Is the tinting an indication of quality? Are these colors acceptable? Do they show that the weld had enough heat to penetrate? Why do they need to be cleaned? The questions are endless. […]
In our previous two articles we talked about categorizing cracks based on when they occur and in which direction they propagate. Today on our third and final article on understanding why your welds crack we look at the importance of location. If you want to review or if you missed our previous two articles simply […]
In our previous post we discussed categorizing cracks based on when they occur. If you missed this you can read it at Understanding Why Welds Crack: Timing. As discussed in this previous article, cracks can and should be categorized based on three criteria: Timing – did the crack occur immediately after welding (hot crack), did […]
Cracks on welds are never good. Welding codes always have allowances for porosity, undercut, weld sizes, and even weld profiles. However, there is never an allowance for cracks. Being a linear discontinuity, a crack will tend to propagate through the weld and into the base metal with relative ease, especially in cyclically loaded structures. So […]
