Precise heat treatment, uniform temperature distribution, and full surface protection of steel.
Hardening salts are specialized mixtures of inorganic salts intended for preparing salt baths used in the thermochemical treatment processes of steel. The use of salt baths guarantees instantaneous and extremely uniform heat transfer, eliminating the risk of deformation and oxidation of the treated parts.
How do hardening salts work in heat treatment processes?
Once melted in a bath furnace, the hardening salt creates a fluid, thermally stable environment with excellent thermal conductivity. Parts immersed in the molten salt are heated evenly over their entire surface.
Depending on the chemical composition and temperature range, hardening salts perform various technological functions:
- Insulation from the atmosphere – the molten salt effectively cuts off oxygen access, protecting the treated parts against decarburization and scale formation.
- Precise and rapid heating – the salt bath transfers heat much faster than atmospheric or vacuum furnaces.
- Controlled cooling – they enable safe isothermal cooling, reducing internal stresses in the material.
Key applications and PEDMO salts offer
We offer a proven range of salts tailored to specific technological processes and steel types:
- Hardening salt SH-630/K – designed for hardening high-alloy steels (operating temperature range: 720–900°C, melting point 600–700°C).
- Hardening salt SH-960/2 – ideal for heating high-speed steel (HSS) tools and structural parts made of high-alloy special steels (operating range: 1000–1350°C). It has a min. 80% barium chloride content.
- Hardening salt SO-140 pp – for tempering carbon and low-alloy steels, stabilizing, isothermal cooling, and uniform blueing (operating range: 160–550°C). It can also be used for the treatment of light alloys (except ultra-light ones with a high magnesium content).
- Hardening salt SO-220 BC – for tempering high-alloy steels, isothermal cooling, and the heat treatment of light alloys – solution heat treatment and aging (operating range: 290–550°C).
Why is it worth using our hardening salts?
- Guarantee of surface cleanliness – after treatment, the parts remain smooth, which shortens or completely eliminates the need for further mechanical cleaning.
- High thermal stability – long bath lifespan and repeatability of hardening results at an optimal level of salt evaporation.
- Reduction of stresses and deformations – the uniform heat flow protects precision components from cracking.
Technical specification
- Physical form: Dry/crystalline mixtures for melting in bath furnaces.
- Application: Hardening, tempering, soaking, isothermal cooling, stabilization.
- Usage: Carbon steels, low-alloy steels, high-alloy steels, high-speed steels (HSS), light alloys.
- Main advantage: No surface decarburization, optimal viscosity of the molten salt, negligible evaporation.