Techno-economic justification for reparatory hard-facing of machine systems working parts

Abstract

Research in the field of hard-facing of various parts of mechanical systems is being done for technical and techno-economic reasons. The reasons for introducing the new reparation technologies by hard-facing are numerous: three quarters of all the mechanical parts of engineering systems could be regenerated or manufactured by hardfacing; the working life of the repaired part reaches or even exceeds the working life of a new part, while the working life of the hard-faced manufactured part surpasses several times the working life of the new part manufactured by some other technology. Large number of damaged and, frequently even broken parts causes terminations of the working process. Thus, due to difficulties in procurement of new, mainly imported parts, the alternative solution must be applied and that is regeneration by hard-facing. It is shown that the a proper choice of the hard-facing technology is related to the complex procedure of checking the quality of the hard-faced layer, what indicates that the reparatory operations could be performed only in specialized regeneration workshops, which are furnished with adequate equipment and corresponding expert and skilled staff. The estimated net benefit for the analysed parts is exceptionally high, regardless of the fact that the additional external and internal effects have not been quantified. After the successful application of these new manufacturing hard-facing technologies it would be possible to create the knowledge base and apply it in maintaining the parts of civil engineering machinery, forging equipment and other similar mechanical parts.