Metal Heat Treatment Insight & Process Applications

Metal heat treatment is a method that strengthens a metal’s structure through direct heating and cooling processes. This allows the user to control and manipulate a metal’s mechanical properties to suit their specific application. Heat treating metal can be a tricky process. It is extremely important that the metal’s mechanical properties are completely understood, while weighing the advantages and disadvantages of heat treatment before starting any project.

Metal Heat Treatment Advantages

Heat treating metal provides a beneficial way to change a metal’s mechanical properties to fit your application needs. However, the heating and cooling process changes the metallurgical structure of the metal, which can cause undesirable side effects such as brittleness and reduced strength. Before beginning any heat treatment project, it is important to gauge the risk factors regarding your particular metal. Metal heat treatment advantages include:

• Increased strength
• Metal stress relief
• Increased wear-resistance
• Decreased brittleness
• Improved electrical and magnetic properties

Metal Heat Treatment Applications

There are several different types of heat treatment processes that allow a metal’s properties to be successfully altered to suit application specifications. Some of the most common metal heat treatments include the following:

Annealing

Annealing is a heat treatment process that heats metal to a specific temperature. The metal is then held at that temperature for a pre-determined length of time and then slowly or rapidly cooled to create advantageous qualities within the metal. Annealing is used to create the following beneficial qualities:

• Refines the metal’s grain structure
• Increases uniformity
• Improves ductility for machining
• Reduces hardness
• Improves corrosion resistance in 300 series stainless steels

Hardening & Tempering

Hardening consists of heating a metal to above 900^oC before rapidly cooling it down within a lower temperature environment or by quenching. Martensitic stainless steels are only able to gain corrosion resistant properties through this process.

Tempering is a secondary process that follows hardening, which is used to introduce ductility to the part, making it tougher and less likely to crack under pressure. Hardening and tempering metal heat treatment processes are often used in the steel pipe manufacturing industry. Hardening and tempering advantages include:

• Lighter, stronger parts
• Increased wear resistance
• Enhanced toughness
• Corrosion resistance initialization

Case Hardening

Utilized as a thermochemical process in which alloying elements, mostly carbon or nitrogen, are added to the surface of a metal up to the case, case hardening heat treatments allow a component to have a ‘soft’ ductile core with a very hard, wear-resistant outer part. Case hardening is appropriate for applications that require specific pressure and wear properties. Beneficial case hardening features include:

• Soft core
• Hard exterior
• Increased toughness & strength

Normalizing

The normalizing heat treatment process requires steel to be heated to around 40^oC above its critical temperature and then held at that temperature for a determined amount of time. The component is then cooled in the open air. This heat treatment is used exclusively for ferrous metals that require a uniform, pearlitic grain size and composition structure at a microscopic level. Benefits include:

• Increased toughness
• Internal stress relief
• Refined grain size

Induction Hardening

Induction hardening is mostly reserved for larger steel and cast-iron parts and components. A high-frequency alternating current is passed through a coil to induce rapid heating of the material that is being hardened, resulting in increased wear resistance and strength. Advantages include:

• Augmented hardness & brittleness
• Increased wear resistance
• Increased strength

Providing the Highest Quality Heat Treated Metals Throughout Southern CA, Arizona & Northern Mexico

Industrial Metal Supply is the Southlands largest supplier of all types of steel alloy grades, metal, and metalworking accessories, including rust prevention products. Get in touch with our sales team for world class metals products and services today.

Check out our steel blog topics to learn more about steel alloys today.