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This article presents the results of abrasion wear resistance tests of wear-resistant steel and surfacing under laboratory conditions and natural operation. Abrasion wear resistance determined on the basis of the study by determining geometrical characteristics of the alloying additives using computer image analysis methods, as well as examining the changes occurring on the surface of the workpieces and their wear intensity. Based on the results obtained from laboratory tests, it was noted that AR steel exhibited 14 times greater wear than the padding weld. This wear is affected by alloy additives, which, for the padding weld, are chromium additives. The microstructure image shows that soil mass had a destructive effect mainly on the matrix of the material, whereas in the areas with high concentrations of chromium precipitates, this effect was significantly weaker. The operational test results showed that within the area of the tine subjected to hardfacing, the material loss was lower than that for the same area of the tine in the as-delivered state. For the hardfaced tine, a 7% loss of volume was noted in relation to the operating part before testing and following the friction process. However, for the operating part in the as-delivered state, this difference amounted to 12%.
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Martensitic low-alloy steels are widely used in machine construction. Due to their declared weldability, arc welding is most often used to join elements made of this type of steel. However, the high temperature associated with welding causes unfavourable changes in the microstructure, resulting in reduced abrasion resistance. Therefore, it is important to know the tribological properties of the welded joint. This article presents the results of a study on the abrasion wear resistance of a welded joint of an abrasion-resistant steel. This study tested a welded joint of an abrasive-resistant steel produced by the arc welding method. Wear testing of the welded joint was carried out under laboratory conditions by the ball-cratering method in the presence of abrasive slurry on the cross-section of the welded joint. Based on the test results, the change in the abrasive wear rate of the material as a function of the distance from the welded joint axis was determined. It was also found that the thermal processes accompanying welding caused structural changes that increased the wear rate index value. Adverse changes in the tribological properties of a welded material persist up to a distance of approx. 20 mm from the weld centre.
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On-stream inspections are the most appropriate method for routine inspections during plant operation without undergoing production downtime. Ultrasonic inspection, one of the on-stream inspection methods, faces challenges when performed at high temperatures exceeding the recommended 52 °C. This study aims to determine the ultrasonic velocity and attenuation with known material grade, thickness, and temperatures by comparing theoretical calculation and experimentation, with temperatures ranging between 30 °C to 250 °C on low-carbon steel, covering most petrochemical equipment material and working conditions. The aim of the theoretical analysis was to obtain Young's modulus, Poisson's ratio, and longitudinal velocity at different temperatures. The experiments validated the theoretical results of ultrasonic change due to temperature increase. It was found that the difference between the experiments and theoretical calculation is 3% at maximum. The experimental data of velocity and decibel change from the temperature range provide a reference for the future when dealing with unknown materials information on site that requires a quick corrosion status determination.
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This paper presents the results of wear tests of three types of commercial abrasion-resistant steels. The samples, cut from commercially available sheets of metal, were subjected to wear tests to a total friction path of 20,000 m. The tests were provided using the "rotating bowl" method in three types of natural soil masses. The soil moisture and test parameters were kept constant. The tests were carried out in six replications for each material. The testing results indicate that hardness does not determine the resistance to abrasive wear, which is supported by the weight loss results for particular materials. Hardox 600 steel, which is not characterized by the highest hardness, exhibited the lowest weight loss value compared to the other materials in all test soils. For the light soil, the weight loss for Hardox 600 was approx. 1.3 times lower than for Hardox 500 steel and approx. 1.6 times higher than for Hardox Extreme steel. With regards to the medium and heavy soil, the weight losses for Hardox 600 in relation to Hardox 500 steel were approx. 1.7 and 1.6 times lower, respectively, while in relation to Hardox Extreme steel the weight losses were 1.5 and 1.7 times higher, respectively.
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This study presents the results of testing for abrasive wear of Vanadis 60 SuperClean powder metallurgy steel as compared to Hardox 600 steel and PMFe60P padding weld. The testing was conducted by the "rotating bowl" method using natural abrasive soil masses. Two types of abrasive masses with particle size distributions corresponding to light soil and medium soil were used. The obtained results enable the conclusion that the weight loss for Vanadis 60 SuperClean powder steel in both types of abrasive mass was approximately seven times lower than that for Hardox 600 steel and two times lower than PMFe60P padding weld. The high resistance of powder steel to abrasive wear in abrasive soil masses is related to the presence of a large number of fine M6C (tungsten-molybdenum) and MC (vanadium) carbide precipitates in its microstructure. The obtained test results indicate that the application of Vanadis 60 SuperClean steel may be extended to working elements operating in mineral abrasive environments.
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The paper discusses the microstructural, chemical and tribological properties of the selected low-alloy, high-strength martensitic boron steels with a hardness of 500-600 HBW. These materials, due to their increased strength, and thus resistance to abrasive wear, are widely used in the mining, agricultural or building industries. Grades such as XAR, TBL and Creusabro were subjected to a comparative analysis. As a result of the conducted research, an attempt was made to determine the relation between the microstructural properties, chemical composition, hardness and abrasive wear resistance of the above-mentioned metallic materials belonging to the same material group. The scope of work involved a metallographic analysis, including the examination of the microstructure with an analysis of the prior austenite grain size. Tribological tests were carried out with the use of a T-07 tester, which is designed for testing abrasive wear resistance in the presence of a loose abrasive. As a result, it was found that the coefficient of relative abrasion resistance kbAV in relation to as-normalized C45 steel is equal to 0.9-1.25 and may even have the same value among materials of different hardness in the as-delivered state.
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This paper presents the results of comparative research on materials used for a track steering system in an abrasive soil mass. Two types of elastomer tracks were tested: a steel-rubber stave from an asphalt paver and a rubber overlay used in vehicles with a steel track chain. The results obtained were related to the wear of Hadfield steel. The tests were carried out on a "spinning bowl" stand in a natural soil mass, which consisted of two types of soil: light and heavy. It was shown that the resistance to abrasive wear depended on the grain size of the worked soil and the chemical composition of the materials. Rubber overlay was found to have the highest resistance index in all types of soils. It was made of high-density polyethylene, low-density polyethylene, ethylene acrylate/ethyl copolymer (ethylene acrylate 18%) and ethylene/propylene copolymer with an ethylene content of 60%. An analysis of the condition of the machined surfaces after friction tests complements the results presented.
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Nitride-bonded silicon carbide is an alternative to steels resistant to abrasive wear. This paper presents the results of a nitride-bonded silicon carbide (SiC) wear test in diverse soil conditions. The test was performed on a "spinning bowl" test stand on three soil types: loamy sand, light loam and ordinary loam. The results were referred to the wear test for materials used to make parts working soil mass, i.e., abrasive wear-resistant steel, boron steel and C + Cr + Nb padding weld. The abrasive wear resistance of silicon carbide was shown to depend on the grain size distribution of the soil being worked. Silicon carbide showed the highest resistance in light soil. However, the padding weld showed higher wear resistance in the other soil conditions. Nitride-bonded silicon carbide had higher wear resistance than the steels under study in all of the soils. These findings are supplemented by an analysis of the condition of the worked surfaces after friction tests. The dominant wear methods in all abrasive masses were micro-cutting and furrowing.
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This paper presents the forecasting of the wear of working elements in an abrasive soil mass using the theoretical wear model. One of the widely used models providing a basis for the relationships describing wear is the Holm-Archard model. This relationship describes abrasive wear because of the contact between two bodies. The model assumes that the wear of an operating part is directly proportional to the sliding force and distance and inversely proportional to the hardness of the material of the part. To date, the model has not been verified in the wear of a soil mass, which is a discrete friction surface. Four grades of steel resistant to abrasive wear, intended for the manufacturing of operating parts exposed to wear within a soil mass, Hardox 500, XAR 600, TBL Plus and B27, were subjected to testing. TBL Plus steel was characterised by the smallest wear irrespective of the soil type. In turn, the highest values of the wear were noted in the light soil for Hardox 500, in the medium soil for XAR 600, while in the heavy soil for B27. Based on the obtained results, a high correlation coefficient was noted, with the highest values obtained for light and heavy soils.