Generator of Controlled Atmosphere
Controlled atmospheres are used nowadays at an ever growing Iarger extent. By means of it. there is not only attained a rationalization of production, but frequently a substantial improvement of quality. In some cases producers passed over at application of controlled atmopheres to entirely new production methods. It is necessary to enlighten the application and production of various controlled atmospheres. At present, there are offered at the market generators of controlled atmospheres, the application of which is for a certain heat-treatment process entirely univocal. In some cases, however, application of the generators is not so univocal, we are therefore recommending consultation with a specialist.
For the producer of equipment for controlled atmospheres it follows hence, to take an intensive interest into all que- stions regarding technics of thermal treatment. Thereto does not only belong metallurgical knowledges and experiences, but also close cooperation with the build-up of the fur nace. Best results ar attained in cases, when the individual parts for thermal treatment, as for inst. the furnace, the generator, the transportation of equipment, the washing machine and the Iike are jointly designed and mutually technically brought into harmony. According to present requirements for equipment for controlled atmospheres, there turns up the possibility of reducing production costs by means of partial series production. Th,at re&ults in the requi- rement for typifying individual generators, on the other side it is, however necessary for this narrowed assortment of generators to meet all requirements of the customers. It is necessary, to divide the whole production process of controlled atmospheres into individual partial processes, and to construct for them in unit assembly principle production units.
Thermal treatment in controlled atmospheres
With the aid of controlled atmospheres we can prevent exchange of components between the material surface and the gaseous environment or to regulate such exchange. For the exchange of components, there are coming into consideration such steel components, which at thermal-treatment temperatures are turning into gaseous state or into gaseous compounds. Those are primarily oxygen, car bon, nitrogen. On the other hand components of hydrogen, sulphur, chromium and the like may also take part in the referred to exchange of components, playing technically a more inferior role.
For the beforehand referred to components (oxygen, car bon, nitrogen), there are stated in Table 1. the gaseous compounds, which are taking part in the exchange of components. Carbon and nitrogen are listed at the Table together, because the simultaneous exchange of both components is technically significant. Articulation of individual columns according to directions of exchange of components is shown in the diagram, which is describing us the processes of the entire thermal treatment with controlled atmospheres. ln spite of this very lucid arrangement of individual processes, we cannot read out of this diagram any direct hints for dividing individual controlled atmospheres.