Heat Treatment

Application

Machined parts, mass production parts, and other carbon steel, low alloy and case hardening steel parts.

Technical specification

Parts up to 500 kg and dimension up to 600 x 600 x 900 mm; maximum treatment tempertaure 1050°C.

Application

Normally performed after hardening, carburizing and carbonitriding.

Advantages

Material properties tailored to desired application; normally to reach desired hardness. Improvement of internal stresses homogeneity; improvement of ductility; surface hardness equalization; and increase of hardness in case of secondary hardening.

Technical specification

To develop tempered microstructure after hardening, the components are reheated to specific temperature bellow Ac1. Tempering temperature and time depend on type of steel and its geometry. Usually more than one tempering treatment is required to obtain desired properties.

Application

Any industrial application with special surface requirements, from wear resistant plates to hot-work tooling and parts with corrosion resistance requirements.

Technical specification

Parts weigh up to 500 kg and dimension up to 600 x 600 x 900 mm treated at temperatures between 490°C and 570°C, depending on the process selected.

Soft nitriding - diffusion zone of selected thickness with no or minimum thickness of compound layer

Hard nitriding - diffusion zone of selected thickness with hard “epsilon” compound layer

Nitrocarburising - compound layer with high epsilon content

A case-hardening process for development of martensitic case-depth of up to 3.0 mm by increasing surface carbon content in austenitic region, with subsequent hardening and tempering.

Application

For components produced using case-hardening steel (low-alloy steel) where good wear resistance, surface resistance to compression, or impact loading is required.

Transmission parts for automotive, rail and energy industry, or other mechanical components.

Benefits

Improves wear resistence, fatigue strength, and general toughness of parts.

Elevated mechanical properties to low-grade steel; high surface hardness while maintaining core toughness.

Technical specification

Martensitic case-depth of up to 3.0 mm is developed by increasing surface carbon content in austenitic region with high carbon solubility. Subsequent hardening and tempering are performed to reach desired properties.

For part dimension up to 600 x 600 x 900 mm and weight of up to 500 kg.

Application

Recommended for highly stressed parts, mass produced automobile parts, gears, or other finished parts made of low alloy and plain carbon steels where extra hard, uniform case is needed.

Benefits

Improves wear resistance, fatigue strength, and general toughness of parts. Higher surface hardness compared to carburizing.

Elevated mechanical properties to low-grade steel; high surface hardness while maintaining core toughness.

Case with improved hardenability and temper resistance due to nitrogen addition.

Technical specification

Treatment is usually carried out in a temperature range from 850 to 890°C in carbon and nitrogen rich atmosphere to develop martensitic case-depth of up to 1.0 mm. Subsequent hardening and tempering are performed to reach desired properties.

For part dimension up to 600 x 600 x 900 mm and weight of up to 500 kg.

Application

Components after being subjected to plastic deformation: gross machining, welding, cold forming, forging or hardening, and generally components where tight dimensional tolerances are required. Generally for steels in annealed or hardened and tempered condition.

Benefits

Reduced residual stresses in bigger and complex parts.

Treatment has no substantial effect on steel microstructure.

Dimensional stability achieved with lowest distortion.

Technical specification

Components are heated below the eutectoid temperature (Ac1) between 450 - 650 °C, using a particular heating and cooling regime. Temperatures are similar to the process called tempering.

Application

For material before heavy machining or forming, before utilizing chilled castings, and generally to obtain fine-grain homogeneous structure and soft malleable material.

Benefits

Improved machinability, isotropy, and electrical properties. Increased ductility and completely relieved residual stresses.

Technical specification

Hypoeutectoid and hypereutectoid steels are full annealed above Ac3, and Ac1 critical line, respectively, with long holding times. Cooling is very slow to obtain soft perlite.

Application

Components after machining, welding, cold forming, forging, or generally after plastic deformation, to relieve residual stresses and obtain homogeneous and fine-grain structure. Normalization is primarily used on carbon and low-alloyed steels

Benefits

Eliminated residual stresses for improved dimensional stability;

Improved machinability, ductility and toughness;

Eliminated dendritic segregation and improved microstructural homogeneity;

Positive effect on subsequent heat treatment quality.

Technical specification

Parts are heated to hardening temperature to form new fine austenitic grains. After short soaking time the parts are cooled. Slow cooling gives a coarse pearlite and fast cooling a fine pearlite.