Safety Assessment of Machine Parts Metallization by CVD-method Using Risk Theory
The use of wear-resistant coatings for strengthening parts under conditions of abrasive and corrosion-mechanical wear is one of the important areas of research on increasing the service life of the machines. Recently, CVD-method of organometallic carbonyl compounds is of great interest, the use of which allows to obtain high-quality coatings and films on the parts with various configurations and chemical composition. CVD-method consists in the evaporation (sublimation) of an organometallic compound in the reaction chamber, and metal deposition on the parts heated to the decomposition temperature of the initial reagent. The main safety problems in the implementation of CVD-method in the industrial conditions are associated with the potential risk of air pollution in the working area with toxic chemicals (starting reagents, auxiliary substances, products of chemical vapor deposition of the organometallic compounds). Toxic compounds can enter the air of the working area during depressurization of the reaction chamber when the faulty equipment is in operation. This can be attributed to the category of emergency situations at the facility, which determines the need for an emergency risk analysis procedure: identifying the conditions for the occurrence and development of a hazardous situation, assessing the risk of emergencies at the metallization site. The results of the application of the method of hazard analysis and the operability of the installation for applying wear-resistant chromium coatings on the precision parts of hydraulic systems by CVD-method of chromium hexacarbonyl are presented. Based on these results, the influence of deviations of the technological parameters metallization from the standard conditions on the possibility of a hazard is assessed in the article. When developing a metallization technology and introducing it at the enterprises, it is required to substantiate safety of all the elements of the production system (raw materials, auxiliary materials, equipment, commercial product) for human health and the environment. Increase of industrial safety in the metallization process is achieved through the automation, equipping the installation for applying metal coatings with the interlock and alarm systems.