What you need to know about heat treating
September 13, 2017
Source: ASM International
Engineered components – from bearings to turbine blades and everything in between – acquire much of their value and application readiness during controlled heating and cooling cycles, otherwise known as heat treating. Though practiced for millennia, the process of heat treating has only, in the last century or so, given up its secrets, making it possible for manufacturers to consistently produce steel and nonferrous metal parts with specific properties and predictable lifetime and performance ranges.
Heat treating leverages the familiar process-structure-property-performance relationship on which modern materials science is based. As metals and alloys are heated and cooled they undergo a series of structural transformations accompanied by the redistribution of constituent elements, phases, and defects. Over the past several decades, industry, academia, and government agencies have invested a significant amount of time, energy, and resources to better understand these changes and how they impact the property and performance parameters of the steels and alloys on which our economy, security, and welfare depend.
With each new discovery, the heat treating process becomes more repeatable and systematic, raising the bar for every participant in the industrial supply chain. To remain competitive, suppliers of all sizes must periodically evaluate and, if necessary, upgrade their heat treating practices. What this entails and how to do it confidently will be conveyed in an instructor-led course called "Practical Heat Treating" that will be held September 25-28 on the ASM International campus in Materials Park, Ohio. The intense four-day course, delivered from a predominantly how-to perspective, will cover the most common heat treat processes and explain how to adapt them for specific materials and properties of interest.
By the end of the course, led by instructor William L. Mankins, FASM, students will be equipped to set up and run any process for standard steels as well as aluminum, copper, magnesium, and nickel alloys. They will also know how to set realistic production goals and track those using standard QC procedures. And when problems arise, they will know how to determine the cause. In most cases, heat treating problems stem from multiple contributing factors. The course will bring many of these into view and offer insights on how to minimize their impact on finished goods.
For more information about the upcoming course click here.
Did You Know:
- Slow cooling can prevent or minimize distortion in tooling with many section size changes.
- The precipitation or dispersion of fine particles during age strengthening tends to bond constituent crystals together at their slip planes, making them more resistant to deformation.
- Hardness and ductility are opposing properties. The harder the material, the less ductile it tends to be, and vice versa.
- Quick quenches can help suppress undesired transformations, phases, and crystal structures, for example, producing hard martensitic steel.
- Alloys, such as bronze, whose constituents remain in solid solution down to room temperature and below, can only be hardened by cold working.
- Annealing causes grain growth and has a smoothing effect on grain boundaries, making metals and alloys more ductile and easier to form.
- Normalizing helps refine grain structure and can minimize residual stress, making precision parts easier to machine, weld, and assemble.
- Tempering relieves stresses that accumulate during the hardening process.