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Reliability evaluation of hardness test methods of hardfacing coatings with hypoeutectic and hypereutectic microstructures

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International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1585-1593页

作者： Nilay Comez Can Civi Hulya Durmus Department of Metallurgical and Materials Engineering Manisa Celal Bayar UniversityManisa 45140Turkey Department of Mechanical Engineering Manisa Celal Bayar UniversityManisa 45140Turkey

hardfacing coatings involve hard carbide/boride phases dispersed in a relatively soft steel *** the hardness measurements of hardfacing coatings,depending on the microstructure,both the hardness test method and the applied load affect the hardness results;therefore,they affect the wear performance predictions of the *** this reason,the proper hardness test method should be determined according to the microstructure of the coating,and the reliability of the obtained hardness data should be *** study aimed to determine the most suitable hardness test method for hypoeutectic and hypereutectic microstructures of hardfacing coatings by analyzing the reliability of Rockwell-C and Vickers hardness test *** analyses showed that Rockwell-C is not a suitable hardness test method for hypereutectic hardfacing *** on the relationship between wear resistance and hardness,Vickers hardness method was found more suitable for the considered materials.

关键词： hardfacing hardness measurement reliability carbide boride wear

Assessment of internal defects of hardfacing coatings in regeneration of machine parts

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Journal of Central South University 2018年第5期25卷 1144-1153页

作者： Jerzy JOZWIK Krzysztof DZIEDZIC Ireneusz USYDUS Dawid OSTROWSKI Grzegorz M KROLCZYK Faculty of Mechanical Engineering Lublin University of Technology Electrical Engineering and Computer Science Faculty Lublin University of Technology Institute of Technical Sciences and Aviation State School of Higher Education Faculty of Mechanical Engineering Opole University of Technology

This paper presents the use of computed tomography for the evaluation of hardfacing. The method used in this research is hardfacing by tungsten inert gas using alloy wires of wear resistant layers. This paper discusses the latest materials used for hardfacing and their application. It characterizes the defects of obtained hardfacing and impact of the type of wire on the concentration of defects. It further, the basic mechanical properties of coatings were determined. The results are subjected to qualitative and quantitative analysis. The smallest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-600 HB, which amounts to 1.5%. The highest average percentage of defects in relation to the overall surface is observed for the hardfacing EL-500 HB, which amounts to 7.2%. The chemical composition of hardfacing has been presented.

关键词： hardfacing coating tomography welding defects

Sintering and Wear Behavior of a FeCrCB hardfacing Alloy Applied by Tape Casting: A Study of Cooling Rate Effect

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Journal of Minerals and Materials Characterization and Engineering 2020年第5期8卷 393-406页

作者： Fernando Valenzuela de la Rosa Roal Torres Sánchez José T. Holguín-Momaca Carlos Domínguez Ríos Alfredo Aguilar Elguezabal Centro de Investigación en Materiales Avanzados S.C. Laboratorio Nacional de Nanotecnología Chihuahua México

This study presents a simple process to deposit a hardfacing coating on a steel substrate, based on the sintering of metallic powder applied by tape casting (by a slurry of metallic powder suspension onto a steel substrate) thus avoiding the use of traditional welding processes and their variants. The effect of the cooling of hardfacing after the sintering process, by air at room temperature or by quenching in water, was studied. This new method ensures a good metallurgical bonding between the substrate steel and the hardfacing layer and shows mechanical property improvement on coated pieces, similar to those exhibited by hardfacing coatings produced by several kinds of welding processes. The characterization of the hardfacing coatings was made by X-ray diffraction, optical microscopy, scanning electron microscopy, microhardness and wear resistance according to the ASTM G65 standard. The characterization results show that the presented faces are: M7C3, M3C, MC, M2B and M23B6;there are three different phases in the micrograph glass phase, eutectic phase and hard phase with a volumetric fraction of 0.14, 0.20 and 0.66, respectively, for the air cooled and 0.15, 0.16 and 0.69 when quenched in water. The average microhardness value for the parts cooled in air was 832.5 HV and for that cooled in water was 958.9 HV, and the wear resistance was a mass loss of 0.219 and 0.128 g for parts cooled in air and water, respectively. These results show that the hardfacing coating could have twice the hardness and wear resistance than that observed for the boron steel used as a substrate.

关键词： hardfacing Sintering Cooling Rate Wear Resistance

Effect of Thermal-Cold Cycle on Microstructure and Hardness of a W-Cr-Mn-Mo-V Ferro-based hardfacing Layer

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材料科学与工程（中英文A版） 2018年第3期8卷 95-99页

作者： ZHANG Zuowei QI Mai Shun ZHAO Jun Logistics Groups Company Yanshan UniversityQinhuangdao 066004China School of Continuing Education Yan Shan UniversityQinhuangdao 066004China Department of Materials and Engineering North China Institute of Aerospace EngineeringLangfang 065000China

The effect of heating temperature and thermal-cold recycle times on microstructure and hardness of a W-Cr-Mn-Mo-V Ferro-based hardfacing layer was *** results show the surfacing layer has good high-temperature stability and ability to resist quench heat and heat *** thermal-cold recycle at 560°C??18°C for 120 times,the hardness of the hardfacing layer is HRC 57.5,its microstructure is mainly tempered martensite and a small amount of retained austenite,when thermal-cold recycled at 680°C??18°C for 120 times,the hardness of the hardfacing layer is HRC 44.5,martensite in the hardfacing layer has almost decomposed.

关键词： W-Cr-Mn-Mo-V Ferro-based hardfacing layer thermal-cold cycles microstructure hardness

Arc Stability Characterization of Double Coated Electrodes for hardfacing

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Journal of Mechanical Engineering Research 2021年第1期4卷 22-28页

作者： Odonel Gonzalez-Cabrera Carlos R.Gomez-Perez HectorA.Kairus-Hernandez-Diaz Felix A.Diaz-Rosell Villa Clara Information and Technological Management Center.Marta Abreu#55 entre Zayas y Villuendas.Santa Clara.Villa Clara WeldingResearch Center.Central University“Marta Abreu”of Las Villas.Carretera a Camajuaní km 5½.Santa Clara.Villa Clara Electrical Engineering.Central University“Marta Abreu”of Las Villas.Carretera a Camajuaní km 5½.Santa Clara.Villa Clara Physics Mathematics and Computing.Central University“Marta Abreu”of Las Villas.Carretera a Camajuaníkm 5½.Santa Clara.Villa Clara

The aim of this work is to establish the influence of the relative position of the alloy charge C-Cr-Mn in the structure of the coating of rutile electrodes for hardfacing,on the operational behavior(arc stability).For this,three variants of electrodes with similar chemical composition are elaborated in the metallic core and the coating,differentiating only in the relative position that occupies the alloy charge(C-Cr-Mn)in the structure of the coating:internal,external and *** the development of the research,a completely random design is *** operative characterization of the electrodes is performed in terms of the arc *** conclusion,it can be seen that the position of the alloy load influences the operation behavior(stability of the arc).The variant of internal alloy charge in the coating presents the better arc stability performance.

关键词： Arc stability Welding electrode hardfacing Position of alloy charge

Effect of Hardfaced Interlayer Thickness and Low Hydrogen Ferritic Capping on Ballistic Performance of Shielded Metal Arc Welded Armour Steel Joints

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Journal of Iron and Steel Research International 2013年第12期20卷 82-91页

作者： M Balakrishnan V Balasubramanian G Madhusudhan Reddy Center for Materials Joining and Research(CEMAJOR) Department of Manufacturing EngineeringAnnamalai University Solidification Technology Division Metal Joining GroupDefense Metallurgical Research Laboratory(DMRL)

Armour grade quenched and tempered steel closely confirming to AISI 4340 is well known for its superior ballistic performance and hence used in the fabrication of combat vehicles. The traditional fillers like austenitic stain- less steel showed poor ballistic performance of these welded joints as compared to the base metal. Attempts have been made to deposit hardfaced interlayer between austenitic stainless steel weld metals. Though this method, mar-- ginal improvements in ballistic performance can be yielded, and cracks were observed in between base metal and hardfaced layer. Thickness of the hardfaced interlayer plays a vital role for the effective ballistic performance. Thus, an attempt has been made to investigate the effect of hardfaced interlayer thickness on ballistic performance of ar- mour steel welds. The results of effect of buttering, low hydrogen ferritic （LHF） filler and three different hardfaced layer thicknesses （4, 5.5 and 7 ram） on ballistid performance of shielded metal arc welded armour steel joints were given.

关键词： armour steel low hydrogen ferritic electrode sandwich structure ballistic performance hardfacing metallography

Study on comprehensive properties of duplex austenitic surfacing alloys for impacting abrasion

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China Welding 2000年第1期9卷 11-16页

作者：孟庆森薛锦 Xi'an Jiaotong Univ Xi'an China

In this paper, comprehensive property crack resistance, work hardening and abrasion resistance of a series of double phases austenitic alloys(FAW) has been studied by means of SEM, TEM and type MD 10 impacting wear test machine. FAW alloys are of middle chromium and low manganese, including Fe Cr Mo C alloy,Fe Cr Mn C alloy and Fe Cr Mn Ni C alloy, that are designed for working in condition of impacting abrasion resistance *** results show that the work hardening mechanism of FAW alloys are mainly deformation high dislocation density and dynamic carbide aging, the form of wearing is plastic chisel cutting. Adjusting the amount of carbon, nickel, manganese and other elements in austenitic phase area, the FAW alloy could fit different engineering conditions of high impacting, high temperature and so on.

关键词： austenite hardfacing impacting abrasion middle chromium

Microstructures and mechanical properties of a martensitic steel welded with flux-cored wires

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International Journal of Coal Science & Technology 2015年第3期2卷 254-260页

作者： Weiqiang Zhang Zhimin Zhong Shaoguang Kang School of Environmental and Chemical Engineering Shenyang Ligong University Shenyang 110159 China China Coal Zhangjiakou Coal Mining Machinery Co. Ltd. Zhangjiakou 076250 China

This study was focused on wear-resistant material prepared by CO2 GMAW method to basically determine the alloys and hardfacing technology which could be employed into mining equipment. Three flux-cored wires with different chemical compositions, marked by DM-I, DM-II and DM-III were used in welding a martensitic steel for the comparison of the microstructures and mechanical properties of the welding metals and HAZ. The results show that DM-I weld metal contains martensite plus other reinforced phases, while both DM-II and DM-III alloys lead to mainly martensitic microstructures with little precipitates. Among all of the tested materials the DM-I alloy has the highest hardness and wear resistance but the lowest impact toughness among the experimental weld metals. Meanwhile, the hardness, impact toughness and wear resistance of the DM-II and DM-III alloys are close to those of the base metal but the DM-III is not as strong as DM-II. Dimples can be found on the impact fracture of the weld metals, but the steel fracture consists of both cleavage and dimples. Thus HAZ has less risk for cracking than the welds, and the DM-II wire which produces the weld having identical mechanical properties to the base metal is suitable for further application.

关键词： hardfacing Microstructure Mechanical property Flux-cored wire GMAW

A Study on Microhardness, Microstructure and Wear Properties of Plasma Transferred Arc Hardfaced Structural Steel with Titanium Carbide

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Journal of Minerals and Materials Characterization and Engineering 2014年第3期2卷 160-168页

作者： Balamurugan Sivaramakrishnan Murugan Nadarajan Department of Mechanical Engineering Coimbatore Institute of Technology Coimbatore India

The Plasma Transferred Arc (PTA) hardfacing allows for homogeneous refined microstructure, low distortion and dilution resulting on enhanced surface properties when compared to hardfacing by conventional welding processes. This paper deals with PTA surfacing of a structural steel with a consumable containing TiC. TiC is a very hard refractory material finding increasing usage for wear resistance application. The composition and amount of heat input evidently affect the microstructure and properties of the hardfacing. The microstructure and microhardness of PTA hardfaced structural steel with TiC were investigated at different heat input conditions across the various zones. The influence of hardfacing parameters on the resulting microstructure, microhardness and wear resistance performance was evaluated. Wear resistance of the hardfaced surface was increased significantly.

关键词： PTA hardfacing Microhardness Microstructure Wear Resistance