硬质合金圆盘刀磨损机理与刃磨过程研究

发布时间：2018-08-07 07:30

【摘要】：金属制品加工产业的转型升级,要求不断提高金属制品精度和材料利用率,将宽幅面的金属板材分切为所需宽度的带材是制作精密金属制品的基础,因此行业发展对金属板材精密分切加工技术也提出了新的更高要求。本文主要以硬质合金圆盘刀与电磁钢板纵向分切过程为研究对象,进行了以下几方面研究：(1)跟踪检测了圆盘刀在分切过程中的刃口磨损状况,研究其磨损规律以提高板材分切质量；(2)对圆盘刀刃磨过程进行了研究,以期制定出最佳的磨削量与刃磨质量标准,有效提高刀具的使用精度与寿命；(3)针对圆盘刀刃磨过程中刃口形成机理进行了分析,对圆盘刀侧面氧化磨损进行了深入研究。对圆盘剪分切技术及工艺、WC-Co硬质合金材料特性及其刀具磨损与刃磨的国内外研究现状进行了归纳综述,理论分析了金属板材圆盘剪分切过程中圆盘刀与板材的受力关系及磨损状况,在此基础上详细分析了圆盘刀刃磨工艺中的影响参数。采用硬质合金圆盘刀对电磁钢板进行了圆盘剪分切实验,利用显微镜、表面轮廓仪等仪器检测了不同分切长度时圆盘刀的磨损情况及其对电磁钢板分切断面毛刺的影响。结果表明,随着分切长度的增加圆盘刀刃口的磨损加剧,刃口半径逐渐增大,侧面磨损带高度也随之增加。圆盘刀磨损过程可以分为初期磨损、稳定磨损和急剧磨损三个阶段,在稳定磨损后期造成带材毛刺过大需要刃磨。圆盘刀磨损直接影响了分切板材毛刺高度,当分切长度达到5000m时,圆盘刀侧面磨损达26μ,刃角半径达到37μm,而对应的分切板材毛刺高度达15μm。在电磁钢板分切实验的基础上,使用万能外圆磨床对硬质合金圆盘刀进行了重新刃磨实验,通过改变磨削量大小研究了不同刃磨磨削量时的圆盘刀刃口质量,探讨了圆盘刀磨损过程与刃磨过程的关系。结果表明,硬质合金圆盘刀刃磨过程中随着磨削量的增加,圆盘刀刃口半径减小、侧面磨损带高度降低,但当圆盘刀刃口半径在达到15μm左右后保持稳定,侧面磨损带始终残留5μm左右,圆盘刀的刃磨锋利度不会随磨削量的增大进一步提升。在采用细磨粒砂轮、小进给量磨削后,侧面磨损区残留磨损带依然存在。为探讨圆盘刀刃磨过程中刃口残留磨损带的形成机理,在平面磨床上对硬质合金圆盘刀进行了模拟磨削实验。结果表明,圆盘刀刃口残留磨损带的存在是由于硬质合金表面氧化造成的,而与圆盘刀圆柱面和侧面的表面粗糙度无关。硬质合金圆盘刀侧面氧化属于常温氧化,是由于环境湿度过大造成的。随着圆盘刀使用年限的增加,圆盘刀侧面表层氧化程度加剧,表层致密度和表面硬度均会下降,导致残留磨损带更易发生。
[Abstract]:The transformation and upgrading of the metal products processing industry requires continuous improvement of the precision of metal products and the utilization of materials. Cutting the metal plates in a wide format into strips with the required width is the basis for the production of precision metal products. Therefore, the development of the industry has put forward new and higher requirements for sheet metal precision cutting processing technology. In this paper, the longitudinal cutting process of cemented carbide disc cutter and electromagnetic plate is taken as the research object. The following aspects are studied: (1) the cutting edge wear status of the disc cutter during the cutting process is tracked and tested. The wear law is studied to improve the cutting quality of plate. (2) the grinding process of disc cutting edge is studied in order to work out the best grinding quantity and grinding quality standard and effectively improve the precision and service life of cutting tools. (3) the mechanism of edge formation in the grinding process of disc cutting edge is analyzed, and the oxidation wear on the side of disc cutter is deeply studied. This paper summarizes the characteristics of WC-Co cemented carbide material and the research status of cutting tool wear and grinding at home and abroad. The relationship between the disc cutter and the plate and the wear condition during the cutting process are analyzed theoretically, and the influence parameters of the disc cutting edge grinding process are analyzed in detail. The disk shearing experiment of electromagnetic steel plate was carried out by using cemented carbide disc cutter. The wear of disc cutter with different cutting length and its influence on burr of electromagnetic plate were detected by means of microscope, surface profilometer and other instruments. The results show that with the increase of the cutting length, the wear of the edge of the disc increases, the radius of the edge increases, and the height of the side wear belt increases. The wear process of disc knife can be divided into three stages: initial wear stable wear and sharp wear. The wear of the disc cutter has a direct effect on the burr height of the cutting plate. When the cutting length reaches 5000m, the side wear of the disc cutter reaches 26 渭, the radius of the cutting edge reaches 37 渭 m, and the corresponding burr height of the cutting plate reaches 15 渭 m. On the basis of cutting experiment of electromagnetic steel plate, a new grinding experiment of cemented carbide disc cutter is carried out by using universal external circular grinder. The quality of the edge of the disc is studied by changing the grinding quantity. The relationship between the wear process of disc cutter and the grinding process is discussed. The results show that with the increase of grinding amount, the edge radius of the disc cutter decreases and the height of the side wear zone decreases. However, the radius of the edge of the disc is stable when the radius of the cutting edge reaches about 15 渭 m. The edge sharpness of the disc cutter will not be further increased with the increase of the grinding amount when the side wear belt remains about 5 渭 m. After small feed grinding with fine abrasive grinding wheel, the residual wear zone of side wear zone still exists. In order to investigate the forming mechanism of residual wear band in the grinding process of disc cutting edge, a simulation grinding experiment of cemented carbide disc cutter was carried out on a plane grinder. The results show that the existence of the residual wear band at the edge of the disc cutter is caused by the oxidation of the cemented carbide surface, but it is independent of the surface roughness of the cylindrical surface and the side surface of the disc cutter. The side oxidation of cemented carbide disc knife belongs to normal temperature oxidation, which is caused by excessive humidity in the environment. With the increase of the service life of the disc cutter, the oxidation degree of the surface layer on the side of the disc cutter is increased, and the surface density and surface hardness will decrease, which leads to the occurrence of residual wear zone more easily.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG711

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