What is the process of hardening steel?

What is the process of hardening steel?

The hardening process consists of heating the components above the critical (normalizing) temperature, holding at this temperature for one hour per inch of thickness cooling at a rate fast enough to allow the material to transform to a much harder, stronger structure, and then tempering.

What are the three steps in the primary hardening method for steel?

Each metal hardening process includes three main steps: heating, soaking and cooling the metal. Some common types of hardening include strain hardening, solid solution strengthening, precipitation hardening, and quenching and tempering.

Which chemical is used to harden steel?

Strong nitride-forming elements (chromium and molybdenum) are required to be present in the steel, and often special nonstandard grades containing aluminum (a strong nitride former) are used.

What is hardening process PDF?

Hardening: The main aim of the hardening process is to make steel hard tough. In this process, steel is heated 30° – 40°C above the upper critical temperature and then followed by continues cooling to room temperature by quenching in water or oil. It is the opposite process of annealing.

How quenching is done?

Quenching is a stage of material processing through which a metal is quickly brought down to room temperature from a high temperature by rapid cooling. Quenching and tempering provides steel with high strength and ductility. During quenching, the following media are used to rapidly cool material: Air/argon/nitrogen.

What is the process of hardening and tempering?

Steels are heated to their appropriate hardening temperature {usually between 800-900°C), held at temperature, then “quenched” (rapidly cooled), often in oil or water. This is followed by tempering (a soak at a lower temperature) which develops the final mechanical properties and relieves stresses.

What is air hardening tool steel?

Air Hardening (A-Grades) This is a very versatile, all-purpose tool steel that is characterized by low distortion factor during heat treatment, due to the increased chromium content. This tool steel has good machinability and a balance of wear resistance and toughness.

What is hardening steel used for?

Hardened steel is resistant to wear, rough usage, high-impact pressure and shock. It is used to make power shovels, steel balls, nozzles, surgical instruments, crushers and plates for rock-processing.

Can you harden steel in water?

ThermTech is proud to offer water hardening of steel components, forgings, machined parts and tooling. Water quench hardening is typically used for low alloy steel grades that require a very rapid quench rate to achieve desired hardness.

What is case depth?

Case depth is the thickness of the hardened layer on a specimen. Case hardening improves both the wear resistance and the fatigue strength of parts under dynamic and/or thermal stresses. Hardened steel parts are typically used in rotating applications where high wear resistance and strength is required.