There are several possible applications of heat treatment to various metals, including steel, and these are used to change everything from hardness and toughness to the strength of a given metal. One such application is known as quenching, which involves rapid cooling of metal.

At Wasatch Steel, we’re happy to advise you on any heat treatment processes for our steel tube, steel pipe or various other steel offerings. This two-part blog will dig into some of the specifics of quenching and what it might be useful to you for, from its basics and the common media used for it to how it interacts with steel specifically.

Basics of Metal Quenching

As we noted, quenching is a process including rapid metal cooling, one designed to adjust mechanical properties of the metal in question. The basic process of metal quenching will go as follows:

• The metal being treated will be heated to a high temperature, greater than it would normally experience – generally somewhere just above the recrystallization temperature for that metal, but still below its melting temperature.
• The metal will be held for a varying period of time at that temperature, allowing heat to “soak in” to the metal.
• From here, the metal will be quenched in one of a few different medium options (more on these later) that will quickly return it to room temperature. This quenching may be extended to allow the coolness to distribute evenly throughout the entire metal.

Media Used for Quenching

When it comes to the media used during quenching, you’ll be considering several factors. Quenching speed, environmental considerations, cost and even media replacement will all have to be factored in. Generally speaking, the following four media types are used for quenching metal:

• Air
• Water
• Oil
• Brine

Part two of this blog will provide further details on each of these media options.

Quenching and Steel

It’s important to qualify a few things when it comes to quenching steel, which is a sensitive material. Doing so requires a process called quench hardening, one where steel is raised to a high temperature and then cooled, changing the crystal structure of the steel. While these processes will generally leave a harder, more brittle microstructure that increase the strength and hardness of the steel, they may also leave steel susceptible to cracking.

In addition, steel that’s been quenched will have significantly less ductility. For this reason, when steel needs to be quenched, this process will often be followed by annealing or normalizing to help minimize these risks and ensure the sensitive metal is not negatively impacted.

For more on metal and steel quenching processes and the details associated with them, or to learn about any of our steel services or steel product, speak to the staff at Wasatch Steel today.