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The article describes the renovation of repeatedly worn shearing tools working cold up to 200 °C. The material from which the cutting punch is made of carries the trade name CALDIE. It is delivered from the smelter in the condition after soft annealing and subsequently it is refined. A worn or damaged edge is chamfered and welded afterwards by technology of micro-TIG in pulse mode. To restore the geometry of the damaged edge is used an intermediate layer between the base material and the final hard layer the ferritic-austenitic wire Cronitex RC 220. Eventually, the final hard layer is welded to the intermediate layer, either Cronitex RC 60 or RC 63. After welding, the tool is machined to the required dimensions and then integrated back into production. The main goal was to evaluate the possibility of extending the life of cutting tools and reducing the implementation of already inefficient repairs. For assessment several destructive tests were performed - macrostructure, microstructure, microhardness measurement and EDS analysis. [ABSTRACT FROM AUTHOR]

The article presents the current state of the use of cobalt in various industries and its possible elimination in the field of welding. In this area, it is used in the form of cobalt alloys which are affected by various mechanical and chemical influences. These alloys are produced by the secondary metallurgical area. The primary area is the chemical industry which reserves all the use of cobalt for the production of Li-ion batteries for electric vehicles at an increasing price. The primary area is the chemical industry which reserves all the use of cobalt for the production of Li-ion batteries for electric vehicles at an increasing price. As it becomes unprofitable for other areas, its savings must be sought. From the point of view of welding technology, the solution could be the use of unconventional and hybrid methods that do not require filler material for the connection of elements. Based on these aspects, the methods of a laser beam, electron beam, and combination of a laser beam with TIG method were selected. Verification of the suitability of the use of the mentioned methods was performed on the abrasion-resistant alloy Stellite 6B. The quality of the joints was evaluated by destructive methods such as microstructure, macrostructure, microhardness, and EDS. After evaluating the results of all samples, the hybrid method in the combination of a laser beam and TIG method seems to be the best. [ABSTRACT FROM AUTHOR]

The article describes problems of hard depositional brazing of wolfram-carbide grains in various matrixes. Especially iron and nickel base matrix on base material from constructional carbon steel. The experimental part was brazed by oxyacetylene flame (method 912 according to EN ISO 4063). The major goals of the experiment were to describe the technological procedure of hard depositional brazing of this specific part. Consequently, were proved wolfram-carbide deposit on two test coupons. These test coupons were metallographically and qualitatively evaluated. The advantage of wolfram-carbide depositional brazing is a service life of deposit, that could be multiple higher, than standard weld deposit with carbon, chromium and vanadium filler material. The advantage is also costly because this kind of braze is cheaper than hard surfacing filler material. This specific application of the wolfram-carbide layer is one of the hardest coatings that could be by flame brazing technology performed. Usage of this application is for example in the mining, woodcutting industry, where it is necessary to improve abrasion and resistance, service life, and guaranteed durability or hardness for cutting tools. [ABSTRACT FROM AUTHOR]

The article describes a replacement and benefits between manual gas metal arc welding (GMAW) with solid wire and semi-automatic flux-cored arc welding (FCAW) with metal fluxcored wire for a specific application of a welded steel compensator used for connecting piping systems to form larger units. For the replacement of the technologies and improvement of the welding efficiency and productivity a specific type of carbon steel mounting insert, DN300 PN16, was selected. Since these pressure parts are subject to the directive 2014/68/EU, both the welding processes have to meet the same welding quality requirements. In particular, they are the welding procedure qualification report (WPQR) and the welder's or welding operator's qualification in accordance with valid European standards. Based on this requirement, a sample was selected so that it would cover the widest possible range of carbon steel mounting inserts produced. This article describes the whole experiment including the selection of the right equipment and filler material, finding the ideal welding parameters, and the subsequent qualification of the welding procedure and the operator with emphasis on the largest possible increase in the welding speed and productivity for these specific weldments. [ABSTRACT FROM AUTHOR]