Once we’ve heated a piece of steel to elevated temperature, it must be cooled in order to complete its transformation into a useful engineering material. Understanding cooling transformations is another important responsibility of the heat treater. Let’s learn more.
If we were traveling from one city to another, we would need to input our destination into a GPS locating device, use an Internet website such as MapQuest® to plot our route or simply pull out a map to help us find our way. The Iron-Carbon, or perhaps more accurately the Iron-Iron Carbide phase diagram (Fig. 1), is nothing more than a roadmap for heat treaters. A phase diagram simply helps us predict what will happen to the internal structure of the steel. Let’s learn more.
Nondestructive testing (NDT) methods are important tools to help us assure product safety, quality and reliability. Finding defects, whether they are flaws or imperfections, during the manufacturing process or before a product is placed into service will decrease liability, increase productivity, save time and improve the bottom line. These techniques are also the first step in any “postmortem” failure analysis.
For anyone involved with heat treating of tool steels, it is critical to remember that there is no such thing as acceptable short-cuts in the heat-treatment process. As such, applying best practices for preheating, austenitizing, quenching, deep-freezing and tempering is mandatory. Let’s learn more.
Of the various nonferrous materials in use today, titanium and its alloys have experienced rapid growth for industrial (38%), commercial aerospace (29%) and military aerospace (23%) products. Titanium alloys are used extensively for heavily loaded aerospace components and most recently because of their excellent compatibility with composites. Interest in titanium will continue to grow as military consumption is expected to double in the next 10 years, and commercial aerospace reports that the world fleet will more than double over the next 20 years (Fig. 1). The heat treatment of these alloys is complex and demands an understanding of the end-use application, desired microstructure and process variables. Let’s learn more.
As heat treaters, we are always looking for ways to shorten our processing times. Increasing carburizing temperature has long been known to shorten cycle times, but grain growth has been our Achilles’ heel. Today there is renewed focus on optimization of diffusion-related processes, and certain microalloying elements show promise for allowing us to raise carburizing temperatures. Let’s learn more.
Heat treaters know gears and bearing races are especially prone to dimensional changes during hardening and quenching, which can cause a number of problems during post-heat treatment manufacturing operations.
When we talk in terms of heat treating in vacuum, most people think we do so in a space entirely devoid of matter. In reality, this isn't true. In practical terms then, a vacuum is a space with a highly reduced gas density. Just how many gas molecules are still present and how they react inside the vacuum furnace is something we should better understand. Let's learn more.
Check out the November 2019 issue of Industrial Heating, featuring the Most-Viewed Vacuum/Surface Treating Articles, "Bringing Machine Learning to Nonmetallic Inclusions in Steelmaking", "The Overlooked Efficiency Opportunity: Intelligent Process Cooling", and much more.