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Influence of Nickel-Based Cladding on the Hardness and Wear Behaviour of Hard-Faced Mild Steel Using E-7014 Electrode Using Shielded Metal Arc Welding
Published in Samson Jerold Samuel Chelladurai, Suresh Mayilswamy, Arun Seeralan Balakrishnan, S. Gnanasekaran, Green Materials and Advanced Manufacturing Technology, 2020
Gursharan Singh, Shubham Sharma, Jujhar Singh, Vivek Aggarwal, Amit Bansal, Suresh Mayilswamy
Hard facing can be applied by a number of welding processes. Selection of the most appropriate welding method for a given job depends on different factors, such as the type of hard facing, component feature, base metal structure, welding equipment functionality and weld component repair status. Hard facing has emerged as a significant process to resolve the issue of wearing in various types of steel, improving the surface properties of components in terms of hardness and wear and corrosion resistance. Some welding techniques used to perform hard facing are mainly used to prolong or boost the service life of the engineering components and to reduce their expense. For hard facing of components, several welding processes can be used, such as oxy-acetylene, shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), flux-cored arc welding (FCAW), plasma arc welding (PAW) and electro-slag welding (ESW) (Okechukwu et al. 2017).
Lubrication and Wear
Published in Neville W. Sachs, Practical Plant Failure Analysis, 2019
Abrasion prevention can involve several approaches; In LSG the hardness of the target material is not as important as the structure. For example, a hardened steel and a hardened cast iron may have identical HRC 58 hardness readings but the cast iron with its extremely hard carbide “islands” will far outlast the hardened steel in many applications. (In the cast iron the carbides are much harder than the HRC 58 overall hardness reading and they act to shield the surrounding matrix from the action of the wear particles. The steel is essentially homogenous and doesn’t have the same ability.) In both gouging and HSG harder target materials with improved fracture toughness are frequently used. Hardfacing, welding an extremely hard and abrasion resistant material on the surface of a target area, is frequently used in the mining and materials processing industries to provide local protection as shown in Photo 8.5. This is a section of a dragline bucket and the weld overlays are laid on top of the bucket steel in a pattern to reduce the abrasive wear. These overlays are typically very brittle but are supported by the tougher and more ductile parent material. Reduce the pressure and velocity of the abrading particles.
Basic Materials Engineering
Published in David A. Hansen, Robert B. Puyear, Materials Selection for Hydrocarbon and Chemical Plants, 2017
David A. Hansen, Robert B. Puyear
The primary use of cobalt alloys is in hard face applications, in which they are regarded as premium materials; Stellite 61 (60Co-29Cr-5W; UNS R30006) is an example. The usual purpose of hardfacing is to improve resistance to abrasion, friction, galling and/or impact. The most common uses of these alloys are in closure applications such as valve seats, where both galling resistance and leak-tightness are required and in abrasive services such as mixers and nozzles. Grinding, requiring wear resistance, is also a common use. Cobalt hard face alloys are typically about as corrosion resistant as the 300-series stainless steels.
Tribological behaviour of the hardfacing alloys utilised to fabricate the wear parts of an excavator bucket
Published in Transactions of the IMF, 2021
Biswajit Das, Kumar Sawrav, Shiv Brat Singh, P. P. Bandyopadhyay
Excavators are widely used for various industrial, mining, agricultural and material handling applications.1–3 The bucket of the excavator engages with the ground, and its components are subjected to mechanical actions such as low stress scratch, high stress cutting/ploughing, fatigue, etc.4 As a result, parts of the excavator bucket are subjected to extensive wear driven by complex wear mechanisms.5,6 Available grades of materials presently used for fabricating these parts cannot combat this wear phenomenon effectively, and the parts need frequent repair and replacement. This, in turn, leads to increase in down time, low productivity, higher operating cost and slows down other linked operations as well.7,8 Hardfacing is a commonly employed technique to improve the surface properties of agriculture tools, components for mining operation, soil preparation equipment and earth moving equipment.9,10
Wear behaviour of hardfacing ultra carbide steel grades
Published in Surface Engineering, 2020
A widely applied method for improving the surface properties of various equipment–such as agricultural tools, mining operation components, and soil preparation equipment – is hardfacing. Hardfacing deposits a homogeneous layer of a high-hardness alloy onto the surface of a soft material (usually low- or medium-carbon steels) by welding. The aim of hardfacing is to increase the hardness and wear resistance of the treated components without any significant loss in ductility and toughness. For welding, chromium-rich electrodes are widely used owing to their low cost and availability of Cr [6]. Some of the welding techniques used for hardfacing include oxyacetylene gas welding, gas metal arc welding, shielded metal arc welding (SMAW), and submerged arc welding (SAW). These techniques mainly differ in their welding efficiency, weld plate dilution, and the manufacturing cost of the welding consumables [7]. Carbon steel is one of the most widely applied materials in industrial production lines owing to its low investment cost, although its mechanical properties and wear resistance are insufficient to withstand long periods of wear. Consequently, attempts have been made to improve the wear resistance of steel by fusing it with alloys and through heat treatment. Although this approach has been found to increase the wear resistance of steel, it generally cannot ensure the operation of production lines for long time periods by fully eliminating the need for repairs [8,9]. Nevertheless, various hardfacing alloys are commercially available for protection against wear. In comparison to the most widely used chromium-rich electrodes and plates, the more expensive tungsten or vanadium-rich alloys offer better performance owing to the beneficial trade-off between their hardness and toughness. Complex carbide electrodes are also used, particularly when abrasive wear is accompanied by other wear mechanisms [10–12].
High-Temperature Tribological Behavior of Nickel-Based Hardfacing Alloys
Published in Tribology Transactions, 2021
Gopa Chakraborty, Revati Rani, R. Ramaseshan, M. Arvinth Davinci, C. R. Das, Tom Mathews, S. K. Albert
From the literature reviewed and presented above, it is clear that in high-temperature wear tests carried out in air, the oxide films formed on the wear track have a significant influence on the wear behavior of the coating. However, for applications in FBRs, the components are in flowing sodium and an inert atmosphere is maintained above the sodium level. As a result, an oxide layer does not form in the flowing sodium environment. However, conducting wear tests in a flowing sodium environment is expensive and time consuming. Hence, a systematic study on the wear and friction properties of three grades of nickel-based hardfacing alloys, namely, NiCr-A, NiCr-B, and NiCr-C, was carried out in a vacuum at 550 °C, the temperature experienced by most of the hardfaced components in a reactor environment, to compare their tribological properties using ball-on-disc abrasive wear tests. The objective is to assess the wear resistance of hardfacing deposits of different alloy compositions in a temperature and environmental condition close to that of actual reactor environment. An oxide film is unlikely to be present both in flowing sodium and in a vacuum. In the former, the flowing sodium removes the oxide film, and in the latter the vacuum environment makes regeneration of the oxide film removed by wear difficult. However, high-temperature wear is a complex phenomenon, and to understand the wear behavior of the hardfacing alloys at high temperature (550 °C), room temperature (25 °C) data should also be obtained as a reference. Further, it has been observed that with a change in composition (mainly with change in weight percentage of nickel and chromium) microstructure, the hardness as well as wear resistance of nickel-based hardfacing alloys, namely, NiCr-A, NiCr-B, and NiCr-C, changes significantly. However, among the same class of alloys, the higher the hardness of a hardfacing alloy, the more difficult it is to carry out hardfacing deposition using the alloy. Thus, when choosing a hardfacing alloy for an application, in addition to wear resistance or hardness, weldability issues should be considered. Hence, identical tests were conducted (a) in ambient conditions, (b) in room temperature–vacuum conditions, and (c) at 550 °C in a vacuum to get an idea of the wear resistance behavior of three grades of alloys. A comparison of the wear properties of deposits of the three alloys in these three distinct environment conditions is not readily available. The wear test results are analyzed and correlated with the microstructure of the hardface deposit. It was expected that the results from the present study would reveal the most suitable alloy among the three grades for hardfacing of the SS structural components of the reactor based on the tribological properties of the alloys at the operating temperature of the reactor. The hardness of the alloy deposit and ease of welding are the parameters considered when selecting an alloy for hardfacing.