The paper presents research conducted in order to achieve some self-shielding armor with high and pre-established strength to intense wear abrasion combined with corrosion, in damp environment, with sulfur content, at temperatures up to 500°C. The first stage was dedicated to the elaboration of the concept of armor and the hardfacing technology, using a hyper-entropic filler metal which assures a self-protection characteristic. The samples used in the experiment were mild steel plates covered with weld in the rhomboid form. In the next stage some investigations were conducted in order to manufacture of new welding materials such as Fe-22%Cr-Mo-V deposited by welding in certain circumstances, having the hardness after welding about 30 HRC. This weld deposit becomes harder after a short working time, having average hardness value of 55 HRC. In stage three some exploratory research was done in order to establish the welding parameters for obtaining the self-protection layers of hyper-entropic material. In the final stage the armor element achieved was tested, to determine performance characteristics during working into the mill fan. After 2 weeks, some samples were sectioned in order to measure the hardening effect during working.

The paper presents a new innovative technology that is experimented to protect from wear crusher jaws that grind basalt aggregates. These are subjected, in exploitation, at the active surface level, to complex requests of wear at abrasion under high pressure combined with fatigue at high efforts. Actual developed stage in casted form from hardened steels present the disadvantage of being sensitive to excavation, pitting type, wear, in hard areas or in those with segregation at the crystalline grain limit. Fighting the above mentioned phenomena’s if accomplished by loading through welding on the jaws active surfaces layers with proper proprieties to obtain intelligent self-protection to wear systems. The thickness of the deposits is determined experimental based on minimizing the tensions on the base metal. The position and geometry of the wear self-protection system were established on data collected from crusher jaws used in exploitation, in Bata quarry, Romania. The morphology of the wear self-protection system layers is developed depending on the type of wear it will encounter during exploitation. Thus in the central impact and wear area, under abrasion and high pressure, depositing the self-protection at wear system consists of alternative rows of tough, hardened, with small grain size materials; in the side areas, subjected to the constant grinded material fall, deposits developed with tough materials. To assure the manufacturing process for the new products, at Sudotim AS Timișoara, we experimentally adapted rods SUDODUR CWTV and SUDINOX CN according to quality-price conditioned imposed as well as its lifespan in exploitation. Requests followed optimizing the product based on minimum price, minimum alloying level and low level of diffusible hydrogen and high purity of base materials.

The rigorous stress conditions of active surfaces, from the components of magmatic rock processing equipment of surface pits, required finding new materials and system processes that achieve major impact on wear processes, in the sense of decreasing them. Conducted research with classic cladding by welding materials showed a high importance of the chromium carbides in the deposits, in the fight against wear. From manufacturing considerations, the participation of chromium carbides in the deposits made with traditional welding materials is 35%, which required finding new ways to obtain superior performances.The group of authors considered the nanostructure method to be convenient, hence of finishing the deposition structure, by introducing in the cladding by welding material composition centers of crystallization with colloidal size and superior temperatures, compared to the molten through welding bath temperatures. In order to achieve a new generation of cladding by welding materials, we proceeded to develop, on the above mentioned principle, rods that deposit by welding alloys like Fe-20%Cr-4%W-1%Ti, nanostructure with melted tungsten carbides and colloidal grinded. The rods thus obtained were used for cladding active surfaces of general purpose extraction and processing machines for basaltic rocks, to achieve highways.Results obtained confirm theoretical assumptions, which led to the implementation of new products in the industrial production.

The research followed the development of deep joint brazing joints with economic efficient materials between the reinforcement, made from sintered wolfram carbide, and the support, drill bit made from low alloy steel with chromium, from the earthmoving equipment. The brazing procedure selected is heating until the semi-products of the addition materials reach melting temperature, with oxyacetylene flame slightly carburized. The pressure of reducing manufacturing costs for drill bits highlighted the need to replace brazing alloys Ag156 according to SR EN ISO 17672 with coated rods type VIAg140R, which are less expensive and successively deposit two layers in one melt, one buffer layer and a filler layer. The buffer layer has a high moistening capacity of sintered wolfram carbides; it contains Ag156 that comes from the coat of the covered rods, in which it participates with up to 10%. The filler layer of the brazed joint is made out of Ag140. The global chemical composition of the deposited metal with VIAg140R complies with prescriptions SR EN ISO 17672 for Ag140. Metallographic analysis and sclerometric tries of specific area of the brazed joints did not highlight any embrittlement imperfections, which lead to the possibility of suggesting the new technology for brazing and extending it to a large number of similar joints

Preventive repeated maintenance concept provides elaborating, developing and reconditioning, repeatedly, in economic efficient conditions, of the pushing blades that equip bulk loading machines, namely leveling them. Applying the solution implies developing and elaborating active areas in direct contact with processed materials by loading through welding. To this end the base material of the blades is chosen to comply with the addition material afferent to the selected process, for predetermined circle tries, approx. 5 in the present moment.Research conducted to validate the loading through welding technology had primary objectives to obtain material couples base/addition that have a high resistance to intense bending demands, under load, combined with a good abrasion usage resistance or high pressure. The chemical composition of the basic materials in the pushing blades, is afferent to high resistance steels, with a maximum of1.6%Mn, max. 1.5%Cr, max.2%Ni, max. 0.7%Mo and max. 0.005%B. The chemical composition of the deposited material, through welding, falls into steel prescription, type Fe-25%Cr-5%W-Nb-Ti-B, with metallographic structures that have a high content of complex carbides and hardness of minimum 60 HRC. Sclerometric tried and metallographic research of specific area of the deposited metal/base metal ensemble did not highlight any imperfections such as cracks or white sports in the thermal influenced areas.Research regarding exploitation behaviour, of basaltic aggregates in loading conditions or cereals, have shown a good resistance at wear.