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 […]
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 […]
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 […]
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 […]
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 […]
Titanium is a metal which is silvery gray in color and has about half the density of steel (0.163 lb/in3). Pure titanium is relatively soft has very low ultimate tensile strength. For use in structural applications titanium is alloyed with chromium and iron, chromium and aluminum, manganese and aluminum and manganese alone. These alloying elements […]
Using the right shielding gas is essential not only to prevent porosity but to get proper penetration, the mechanical properties you desire including weld strength, and overall weld quality. In order to select the right shielding gas you need to consider the following: – Alloy of filler metal – Material thickness – Mode of GMAW […]
When it comes to fillet welds, bigger is not always better. A fillet weld is easy to measure, simply take out your fillet weld gauges and measure it. However, there is an incorrect assumption that a bigger weld (as measured with a fillet gauge) is always stronger than a smaller weld. Before we get into […]
It is not uncommon to find fabricating shops that are welding a variety of metals including carbon steel, stainless steel, aluminum and nickel alloys. In many cases some of these materials need to be welded to other types. Once very common situation, especially in automotive applications is welding carbon steel to stainless. One of the […]
Preheating of structural steels is carried out primarily to slow the cooling rate after welding and prevent the formation of martensite. Martensite makes the weld and the heat affected zone (HAZ) very hard and brittle. This newly formed microstructure is susceptible to cracking. By slowing the cooling rate we reduce or eliminate the formation of […]
