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Understanding solution heat treatment, annealing, nitriding

Solution heat treatment and annealing are the common method of heat treating nonferrous metals. in a previous post, I examined the process of heat treating, ferrous metals like steel. Today you’ll get to know the following process of heat treatment which includes solution heat treatment and annealing. you’ll also learn about precipitation hardening, nitriding, cold working, decarburization.

Read more: Heat treatment process of steel

solution heat treatment, annealing, nitriding, precipitation hardening, quenching, and cold working

Solution heat treatment

It is carried out to increase the tensile strength of nonferrous alloys changing them into a solid solution and controlling the rate of returning to a changed structure of their mechanical mixture. In this heat treatment, the alloys are heated to a specific temperature below the melting point of the materials, it is then quenched or rapidly cooled. The solid solution obtained during the heating process remains stable due to the cooling process. At this point, aging and precipitation hardening (a process that helps the materials in alloy to change or precipitate out of the solid solution.) will be done to ensure the alloy does not change to its original configuration after some time. Aging gives the resultant grain structure in the metal a greater tensile strength than its original condition. Base on the alloy type, the artificial aging process can also consist of simply aging the alloy at room temperature for a specific time and then cooled with air.

Read more: Heat Treatment of Aluminum and Aluminum alloys

Watch the video below to learn how aluminum undergoes solution heat treatment:

Read more: 3 Stages of Heat Treatment Process

Annealing

annealing of nonferrous metals can be achieved as far as nonferrous metals are heat-treatable. Annealing is done to relieve the hardness of cold working. Just as it is being done in ferrous metals, by subjecting the alloys to heat at a specific temperature and then allowing it to cool slowly to room temperature. the slow cooling allows full precipitation of the constituents and produces a refined microstructure. Whilst rapid cooling will cause nonferrous alloys to become softer than normal state.

Let me use this opportunity to explain some terms you need to know to get enough of this course

Quenching

This is the process of cooling metal at a rapid rate by immersing it in oil or water.

Read more: Heat treatment of metals: definition, purpose advantages, and disadvantages

Precipitation hardening

It is also known as age hardening or aging. It is accomplished if certain metals are held at elevated temperatures without quenching. Precipitation hardening helps to increase the yield strength of malleable materials.

When precipitation hardening metals are quenched, its alloying elements trapped in solution which causes a soft metal, and when solutionized metal undergoes aging, it allows the alloying elements to diffuse through the mere structure and form intermetallic particles. These intermetallic particles will form into the nucleus and fall out of solution helping increase the strength of the alloy.

Nitriding

Nitriding is another way of hardening an alloy. It is carried out by adding nitrogen to a metal surface through content with ammonia gas. This process produces case hardening if it’s not quenched.

Decarburization

This is done to remove carbon from the surface of the steel, either by subjecting the metal to heat or by the aging process of oxidation.

Read more: Different Types of Nonferrous Metals and their Uses

Cold working

This process is not a heat-treating process, but it is used to change the characteristics of metals. It is performed by deforming metals at room temperature without fractioning. Cold working gives more tensile strength and better machinability to the metal. However, it changes its shape.

Read more: Heat treatment of copper and copper alloys

That is all for this post, where solution heat treatment, annealing, nitriding, precipitation hardening, quenching, and cold working is being explained. I hope you get a lot from the article, if so, kindly share with other students. Thanks for reading, see you next time!

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