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This type of heat treatment of steel and other iron alloys allows for higher hardness but also higher brittleness therefore making the material more susceptible to cracking. This treatment is carried out at different temperatures depending on the type of steel. The process consists of heating the steel parts and keeping them at a certain temperature and then cooling them down. Depending on the desired effects, the cooling time and the environment (to which oil, water, air or salts are introduced) are chosen. It is also important to reduce the stresses and strains that occur when changing the structure of the workpiece, and to achieve the best results in this respect, you should consider heat treatment with isothermal transition..

Vacuum hardening

This advanced type of heat treatment of metals is carried out at high temperatures. It includes austenitization at 800 to 1200 oC, followed by rapid cooling and tempering to maintain the structure of martensite or bainite. This machining ensures extremely high hardness and strength of steel.

Metal hardening – the process and uses

The heat-hardening process is carried out mostly on steel and other iron alloys. The heat treatment of steel makes the various components of the material harder, but also makes them more brittle. Metal hardening at Sacher is carried out at different temperature ranges, which depend on the specifications of the metal alloy used. The heat treatment consists of three main stages: heating the metal, keeping it at the set temperature for a certain period of time, and then controlled cooling. Each stage requires careful planning of aspects such as time, intensity, and (in case of cooling) the external environment: oil, water, air or salts. As part of our services we also offer the heat treatment of metal with an isothermal transition. This process reduces the risk of deformations on materials with less resistance to temperature fluctuations.

Our services also include austenitization of steel at temperatures as high as 1200 degrees, which is about 70 degrees from the solidus line. A great follow up to austenitization is vacuum hardening, where we perform immediate cooling after heating the material to high temperatures. The end result of this process is an extremely tough and sturdy material, ready for use in a wide range of industries.

Hardening stainless steel

In response to the industry’s demand for steel hardening, Sacher’s services also include stainless steel hardening, which improves its strength. Good steel hardening results in a duplex material with excellent corrosion resistance. The stainless steel hardening service is also used for ferritic-austenitic steel, which has the opinion of being a very soft material. In order to avoid deterioration of its anti-corrosive properties, we heat austenitic steel up to 1100 degrees and then temper it. The hardening level of steel is largely dependent on chromium and carbon content. The higher the concentration of these elements in the material, the better the results of the hardening process are. The heat treatment of metal carried out at Sacher gives it the qualities it needs in various industrial sectors. Hardened steel serves as the primary construction material of agricultural and construction machinery and is also used in the manufacture of cars and spare parts. Stainless steel components can also be found in small household accessories that are constantly exposed to moisture. A wide range of applications for stainless steel makes the process of hardening a key factor that increases the end product’s performance.

Surface hardening of steel

The steel strength improvement methods discussed above are collectively referred to as volumetric hardening. Sacher’s offer also includes other types of heat treatment on metals such as surface hardening of steel. The surface tempering process involves heating the steel until a typical tempering temperature is obtained, and then exceeding this temperature by a further 50 degrees. In surface tempering, the cooling of heated steel at a higher rate than critical becomes crucial. This rapid change in temperature ensures that the surface layer of the material achieves maximum hardness and wear resistance, but the properties of the core itself do not change. We conduct surface hardening of steel in induction, bath, flame, or beam techniques. The thickness of the hardened coating can be freely modified by changing the austenitization and cooling temperatures. This ensures that the steel parameters are exactly the same as the desired specification for the future product. Surface hardening of the steel makes it more resistant to cracks and deformations. This type of hardening is also used to reinforce a selected area in a given component, such as a crankshaft and other geometrically complex car components.

Vacuum hardening of steel

Vacuum hardening is an essential service for acquiring a clean surface material, with high shape reproducibility and minimal distortion. As part of Sacher’s offer, we perform vacuum hardening of steel in a volume model where the cooling process occurs in highly pressurized liquids or gasses. By minimizing material distortion, we reduce the surplus material that would require grinding. The result is a product that is highly repeatable, which also optimizes production costs. Vacuum hardening is carried out in advanced vacuum furnaces, which allow for e.g. cooling in nitrogen at pressures of up to 15 bar. Steel vacuum hardening services are suitable for the manufacturing industry, especially in the fields of machine and vehicle technologies. Sacher offers comprehensive metal hardening services, improving their physical properties and making the material wear resistant.