The metals/materials technology area has information on the most commonly used materials in metal fabrication ̶ carbon steels; stainless steels; high-strength, low-alloy steels (HSLAs); and the 6000 series aluminum ̶ and those that aren't as common, such as the red metals, refractory metals, titanium, and magnesium.
March 19, 2015
In terms of temperatures, the heat-affected zone (HAZ) has it all—from near liquidus to near ambient and everything in between—a fact that makes the HAZ a tricky piece of real estate to understand the predict. Why? Remember, a number of metallurgical changes can take place in hot metal, and...
March 17, 2015
Gas-metal reactions take place every time you weld. They happen quickly, especially at temperatures above 3,000 degrees F, and can cause serious problems. Of course, not all gas-metal reactions are bad; some are designed in, while others simply take place with no ill effects. But some prove quite...
March 16, 2015
There’s a lot going on as your weld puddle solidifies. Grains are trying to grow in a variety of directions, and the entire process can get quite competitive, because some grains grow faster and block the growth of others. Which grains grow faster depends on their orientation at the point where...
March 9, 2015
Welding metallurgy is a science, but it’s far from perfect. I mention this here because my January/February column elicited a number of critical, if not scathing, e-mails concerning everything from a typo in Figure 3 to my generalizing the precise and exacting science of metallurgy. The...
March 9, 2015
As I mentioned in the September/October issue, welding can severely influence strengthened or hardened metals, depending on the hardening technique used. Hardening Techniques and Welding Effects Work- or strain-hardened metals exposed to the intense localized head of welding tend to recrystallize...
March 9, 2015
It’s time to narrow our focus and look at the science of welding metallurgy, a branch of metallurgy that addresses the behavior of a metal during welding and, just as important, the effects of welding on a metal’s properties. Think about what happens when you weld together two pieces of...
October 29, 2014
Metal service centers are a vital part of the fabricating world, and their fortunes are closely aligned with their customers’. Here’s a look at how one center fared during the Great Recession and where it’s headed with its young CEO at the helm.
October 20, 2014
Additive manufacturing is changing fundamental concepts of design, engineering, and production. As part of this, metal additive processes, including powder bed fusion and directed energy deposition, are allowing industry to fabricate metal products in entirely new ways.
January 30, 2014
Precrimped woven wire mesh is a smaller part of the metal fabrication world, but it does have a significant presence in some industrial applications. This overview explains just how the mesh is created and gives metal fabricators an idea of the basic crimp styles that are available.
December 12, 2013
Editor’s Note: This article is Part III of a three-part series that reviews the die materials and die coatings used in forming AHSS. Part I, which appeared in the January/February issue, discussed the relationship between process conditions and tool failure mechanisms. Part II appeared in...
October 7, 2013
Applying a corrosion prevention product to steel isn’t enough. If the workpiece is contaminated with something as minor as fingerprints or steel fines, corrosion can get a foothold. Understanding the components that make up a corrosion cell, and how a corrosion cell works, is necessary in learning how to prevent corrosion from getting a start.
September 5, 2013
Maintaining a boiler system can be very expensive and require a lot of downtime for the equipment. The electric arc wire thermal spray process is one efficient way to create a protective overlay on boiler components and systems, helping to reduce replacement costs and outage times.
October 8, 2012
Free-machining steels shouldn’t be welded. If a fabricator has a job requiring a free-machining steel, engineers and fabricators should get together to determine the best action. Can welding be avoided by using fasteners? If not, which weldable materials exhibit acceptable machining characteristics, and do these materials meet design requirements?
September 10, 2012
At least a dozen chromium molybdenum (CrMo) steel combinations exist. One of the more recent alloys consists of chromium, molybdenum, vanadium, niobium (columbium), and nitrogen. Beginning sometime in the 1970s, this material became popular for use in high-temperature applications, such as gas and...