Masking compounds

Masking compounds are used in the thermochemical treatment of metals (mainly steel) to prevent elements such as C, N or B, which enhance the hardness, from diffusing into certain areas of the components. Masking compounds with a solvent base to protect against carburization in a partial vacuum. Durferrit Contradur UDK is a solvent-based masking compound which was specially developed for use when carburizing at low pressure or under vacuum, and which can also be used in gas carburizing Some of the features of Contradur UDK are: the protectants have a minimum vapour pressure the product does not run while in the furnace there are no problems during high pressure gas quenching it can be easily removed with water in an industrial washing machine after heat treatment. Solvent-based masking compounds are used when the thermochemical heat treatment is to be carried out in gas atmospheres. Durferrit Contradur and Contradur OX can also be used for protection when carburizing in granulate.

Nitrocarburizing

The term nitrocarburizing means an enrichment of the surface layer of ferrous materials with nitrogen and a small amount of carbon. This thermochemical treatment improves the wear resistance and the fatigue strength. Used with a strongly oxidizing cooling bath - TENIFER®-QPQ - wear and corrosion resistant surfaces with an attractive black appearance are produced. Products used in nitrocarburizing TF1 cyanide-free top-up salt for TENIFER® baths*; used for treating ferrous materials. Used only in combination with the REG 1 regenerator. Working temperature 480 - 630°C. REG 1 environment-friendly, nontoxic regenerator for TF 1 baths AB 1 oxidative salt for cooling parts treated in TF 1 baths; greatly enhances the corrosion resistance (TENIFER®QPQ process). The well-known traditional Durferrit NS salts are still available*.

Plant Technology

In recent years, environmental demands have led to developments which have opened completely new perspectives for the salt bath technology of Houghton Durferrit GmbH, with its more than 75 years of experience. The concept of effluent-free salt bath heat treating systems developed by us, and in successful operation for over 10 years, enables processes to be performed without liquid wastes occurring. In addition, it is also possible to minimize the water consumption by using a modern cascade technique. After being heat treated, the components are thoroughly rinsed in a cascade system which requires a minimum of fresh water, and which processes the relatively small amount of rinsing water very economically. This system is automatically included in offers for new heat treating plants. Furthermore, our waste air cleaning plants remove the salt fumes occurring above the salt baths. This means the German Regulations for protecting operators at the work place (MAK limits) can be kept to with no difficulty. The purity level of the cleaned air complies with the German TA Regulations. Our speciality is the solving of individual heat treating problems, and we can document our success in almost all branches of industry. Given overleaf are just some of the fields of application and use in the heat treating sector.

Salt bath technology

Durferrit salts are used as salt melts within a temperature range of 150°C to 1300°C: The extremely high heat storage capacity and the heat transfer properties of salt melts are used to good effect for the transfer of heat in chemical reactors in the chemical and rubber processing industries. These chemical reactors contain up to several 100 tons of salt. In the rubber processing industries rubber profiles, among other products, are vulcanized in continuously operating plants. Vulcanizing plant