刮板输送机中部槽用高铬堆焊耐磨板的组织特征及滑动磨损性能

Microstructure and Sliding Wear Properties of High Chromium Hardfacing Plate for Middle Trough of Scraper Conveyor

为探讨CM550复合耐磨板用于煤矿刮板输送机中部槽的可行性,结合刮板输送机中部槽的磨损运动特征,研究CM550高铬堆焊耐磨层的组织结构和磨损性能,并分析其磨损损伤机制。金相、XRD和TEM组织结构分析表明,高铬堆焊层与Q235基体之间形成冶金熔合,堆焊层的相组成主要为α-Fe和CrC碳化物,其中碳化物以初生棒状、共晶片状和粒状二次碳化物的形式存在。滑动磨损实验结果表明,在相同的摩擦因数条件下,CM550耐磨板的相对耐磨性是NM450耐磨钢的2倍以上,摩擦副材料的磨损质量损失也处于相同水平。石英砂磨料磨损的损伤主要来自硬石英砂颗粒的微切削磨损和软质铁素体区的变形剥落磨损,铁素体磨损暴露于磨损表面的硬质碳化物承担了主要的磨损载荷,阻止了石英砂磨料与软铁素体的直接接触,减轻了铁素体的进一步磨损,有效提高了耐磨性。因此,CM550高铬堆焊耐磨板可推荐为刮板输送机中部槽和煤矿各种耐磨衬板制造的耐磨材料。

In order to explore the feasibility of CM550 composite wear-resistant plate used in the middle trough of scraper conveyor in coal mine, the microstructure and wear performance of high chromium hardfacing wear-resistant layer were studied, and the wear damage mechanism was analyzed, combined with the wear movement characteristics of middle groove for the scraper conveyor.The microstructure analysis of metallography, XRD and TEM shows that the metallurgical fusion is formed between the hardfacing layer and Q235 base steel.The phase composition of hardfacing layer is mainly α-Fe and CrCcarbide, in which the carbide exists in the forms of primary rod carbides, eutectic flake carbides and secondary granular carbides.The formation of hard CrCcarbides increases the hardness of hardfacing layer, which effectively improves its sliding wear resistance.The experimental results of sliding wear reveal that the relative wear resistance of CM550 hardfacing plate is more than two times that of NM450 wear-resistant steel, and the wear mass loss of friction pair material is also at the same level at the similar friction coefficients, which fully meets the design and application requirements of middle trough of scraper conveyor.Under the condition of sliding abrasive wear of quartz sand, the wear damage mainly comes from the ploughing wear of hard quartz sand particles and the deformation peeling wear of soft ferrite area.After ferrite wear, the hard carbides exposed on the wear surface not only bear the main wear load, but also prevent the direct contact between quartz sand particles and soft ferrite, and avoid the further wear of ferrite.Therefore, the CM550 high chromium hardfacing wear-resistant plate is recommended as a wear-resistant material for the manufactures of middle trough of scraper conveyor and various wear-resistant lining plates in coal mine.