Steel gears are vital components for many industrial applications. However, gears and sprockets can take a great deal of wear and tear, and it’s important to use materials that are tough enough for the job. That’s why many companies today choose carbonitriding for heat treatment of gears. Here is more about this method and some of the benefits it offers.
Making Steel Harder
Carbon is one of the most common alloys for steel. It strengthens it and this process is known as carburizing. When steel is heated in the right atmosphere, it traps carbon particles and becomes austenite. Once cooled, the carbon steel turns into martensite. It’s possible to carburize (case harden) steel in one of several methods. For example:
Gas – Methane or propane powered furnaces provide enough heat for hydrogen to become carbon and is a common method for heat treatment of gears. As the iron is heated, the carbon atoms combine with the steel. Rapid cooling methods (quenching) help to keep the carbon trapped inside the steel, and this is done with water, chemicals, or oil.
Liquids – cyanide can be an effective way to carburize iron. The metal is placed into a salt and cyanide solution under high heat. This rapidly produces hardened steel, but because of its toxicity and potential for hazards, it’s usually done in small operation under strictly controlled environments.
Carbonitriding – when you add nitrogen and carbon to iron you create steel that does not fatigue easily. This is often by using ammonia instead of methane or propane. Heat treatment of gears with carbonitriding can be done at lower temperatures than standard heat-treating methods.
Why Gears Must be Toughj
Gears are often under a high degree of stress, heat, friction, and this can result in premature wear. Heat treating methods like carbonitriding helps to keep the gears of modern industry turning.