硬质合金的深冷处理工艺及其研究进展

简要介绍了程控深冷处理装置,分析探讨硬质合金深冷处理工艺的基础理论研究;综述了目前硬质合金深冷处理的应用现状及其研究进展,并展望了硬质合金深冷处理的发展前景及发展方向。     

硬质合金及其涂层深冷处理的研究与展望

概述了国内外硬质合金的深冷处理工艺,分析了深冷处理工艺对硬质合金性能和涂层硬质合金性能的影响及机理。指出了硬质合金深冷处理工艺存在的不足。最后展望了硬质合金及其涂层深冷处理的发展方向。     

硬质合金深冷处理的研究现状

对硬质合金深冷处理的工艺流程及设备进行研究,分析了深冷处理对硬质合金微观组织、相结构、力学性能、切削性能的影响规律,对硬质合金深冷处理的应用前景及其发展方向进行了展望。     

硬质合金深冷处理技术及其发展概况

介绍了国内外硬质合金深冷处理的发展概况和硬质合金的深冷工艺,深冷效果及其强化机理。硬质合金深冷处理后主要提高了材料的耐磨损性能;对硬度、抗弯强度、密度、磁性能等其它物理性能和微观组织的影响不显著但是硬质合金深冷处理后,ε-Co含量和表面残余应力增加,其强化机理主要是相变强化和表面残余应力强化。     

硬质合金刀具深冷处理技术的研究现状及进展

深冷处理作为材料的一种有效无损改性技术,得到广泛应用。介绍了深冷处理的工艺参数,综述了国内外硬质合金刀具深冷处理技术的研究现状,分析了硬质合金刀具深冷处理的作用机理,并提出了一些深冷处理技术的工业化应用展望。     

深冷处理对硬质合金的影响

综述了国内外硬质合金深冷处理的工艺过程及其深冷处理对硬质合金微观组织、相结构、残余应力状况、机械性能与切削性能的影响。深冷处理工艺包括降温和保温两个基本阶段,部分研究增加回火处理;深冷处理后硬质合金中η相含量增多且尺寸减小,Co对WC的粘结更紧密,但也有认为微观组织形貌变化不大的观点;Co相由面心立方向密排六方转变,而WC相变化不大;深冷处理可提高硬质合金耐磨性和延长使用寿命已得到共识,但对表面残余应力状况及硬度等影响尚存在不同观点。探索深冷处理对硬质合金的作用机理,并进行工艺参数的优化是目前研究工作的方向。     

硬质合金锪刀的深冷强化处理

研究深冷处理对YG8硬质合金物理机械性能的影响，选择硬质合金锪刀的强化处理工艺。实验证明：锪刀经深冷处理后，其刃磨使用寿命提高3．7～5倍，取得明显效果。在此基础上，初步探讨了深冷处理对硬质合金锪刀强化的机理。     

深冷及深冷后回火处理对截齿硬质合金头耐磨性的影响

选取YG8硬质合金作为掘进机截齿硬质合金头的材料,研究深冷工艺和深冷后回火工艺对YG8硬质合金耐磨性和平均摩擦因数的影响,并通过扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)探究两种工艺对YG8硬质合金相组织的影响.结果表明,深冷后回火处理在减少YG8硬质合金磨损量方面更明显.深冷处理在降低YG8硬质合金...     

硬质合金深冷处理技术发展及研究进展

介绍了国内外硬质合金深冷处理的技术发展及研究进展和深冷工艺,深冷效果,强化机理及其影响因素。硬质合金深冷处理后主要提高了工模具的耐磨性能和使用寿命,其它物理性能的影响不明显,其强化机理主要是相变强化和表面残余应力强化。     

深冷处理对硬质合金性能的影响

本文对牌号为YL20.3的硬质合金顶锤材料深冷处理后的力学性能和磁性能进行了研究。研究结果表明:硬质合金在深冷处理后显微硬度从1610HV升高至1689HV,抗弯强度由2447.06MPa下降至2300MPa,试样经深冷24h处理后饱和磁化强度由10.21CGS·cm3/g降低至9.70CGS·cm3/g,而矫顽磁力稍有升高,深冷处理2h达到最大值13.39kA/m。结合合金X射线法残余应力检测结果分析,深冷处理对材料中残余应力的改变是硬质合金性能变化的主要原因,深冷处理的时间是主要工艺参数。     

磁场深冷处理对YG11C硬质合金耐磨性的影响

基于深冷处理提供的温度场和永磁体提供的匀强磁场,对YG11C硬质合金进行磁场深冷处理,并与常规工艺和深冷处理工艺进行了对比分析。结果表明: 深冷处理较常规处理,其耐磨性提高了约35%,磁场深冷处理相应降低了约21%。在微观机理上,深冷处理后合金中η相碳化物数量增加是耐磨性提高的主因。磁场深冷新工艺处理后,合金中α-Co向ε-Co 转变增多,使得粘结相变脆且塑性变形能力降低,从而使得耐磨性降低。     

深冷处理对YG10硬质合金磨损性能的影响

以YG10硬质合金为研究对象,深冷处理技术为手段,采用正交试验的方法,在不同深冷温度、深冷时间、交变次数的情况下对其进行深冷处理,并对处理后的试样进行磨损试验、硬度试验和显微组织分析试验.结果表明,最优深冷处理工艺使YG10合金显微硬度提升33.6％,耐磨性提升72.8％,深冷温度是影响YG10合金耐磨性能最大的因素....     

Performance evaluation of cryogenically treated tungsten carbide tools in turning

This paper describes a study on the effects of cryogenic treatment of tungsten carbide. Cryogenic treatment has been acknowledged by some as a means of extending the tool life of many cutting tool materials, but little is known about the mechanism behind it. Thus far, detailed studies pertaining to cryogenic treatment have been conducted only on tool steels. However, tungsten carbide cutting tools are now in common use. The main aim of this study is to analyze the differences in tool performance between cryogenically treated and untreated tool inserts during orthogonal turning of steel. This will aid in the quest for optimal cutting conditions for the turning of steel using these inserts, and will also enhance the understanding of the mechanism behind the cryogenic treatment of tungsten carbide, and the changes in its properties after cryogenic treatment. In the process of ascertaining these findings, it was shown in this study that under certain conditions, cryogenic treatment can be detrimental to tool life and performance. It was also shown that cryogenically treated tools perform better while performing intermittent cutting operations.     

Effect of Deep Cryogenic Heat Treatment on the Wear Behavior of Carburized DIN 1.7131 Grade Steel

The effects of the deep cryogenic heat treatment on the microstructural changes,wear resistance,and hardness of carburized DIN 1.7131 grade steel were investigated.Results show that cryogenic heat treatment reduced the retained austenite and increased the carbide amount.In addition,after the cryogenic heat treatment,carbide shows a more uniform distribution,as compared to the conventionally treated ones.It was also clarified that the hardness of the cryogenically treated samples was improved,but the relative improvement decreases with the distance as the surface increases.It has been shown that the wear resistance improves due to the cryogenic heat treatment,and the predominant wear mechanism is a combination of the adhesive and tribo-chemical wear.     

深冷处理对K6509钴基合金表面性能的影响

研究了K6509钴基合金样品在-196 ℃液氮中分别深冷24 h和48 h后的表面性能变化,并与未深冷样品进行对比。通过显微组织分析、XRD成分分析、硬度分析等技术手段研究了深冷处理对钴基合金表面性能的影响,并分析了深冷处理和滚磨光整加工后表面粗糙度和形貌的变化。结果表明:钴基合金在深冷处理24 h时,有部分碳化物发生粗化,同时伴随着细小碳化物析出,深冷48 h时细小碳化物减少,碳化物粗化现象消失,显微组织变得均匀;通过XRD图谱发现,深冷过程中相组成没有发生变化,但含M₂₇C₆碳化物的共晶相和含M₇C₃碳化物的共晶相出现峰移现象,M₂₇C₆碳化物相衍射峰强度发生明显变化;延长深冷时间能够显著提高硬度,深冷48 h硬度提高了17.6%;选择合理的深冷时间与滚磨光整加工相结合能显著提高表面质量,经深冷48 h+滚磨光整处理后,表面粗糙度下降最多,R_a由1.215 μm降到0.662 μm,其表面缺陷明显减少,表面一致性好。     

Effect of Carbide Distribution on Corrosion Behavior of the Deep Cryogenically Treated 1.2080 Steel

Deep cryogenic heat treatment is a supplementary process performed on steels specifically tool steels before tempering to improve the wear resistance and hardness of these materials. The carbide distribution changes via the electric current flow or the application of a magnetic field during the deep cryogenic heat treatment. Hence, the electric current and the magnetic field were applied to the samples to investigate the corrosion behavior of the deep cryogenically treated samples by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The results showed that increasing the carbide percentage and achieving a more homogenous carbide distribution during the deep cryogenic heat treatment will remarkably decrease the corrosion resistance due to a decrease in the solutionized chromium atoms in the structure as well as the increase in the martensite-carbide grain boundaries (the galvanic cell areas). Moreover, it was clarified that the electric current flow and magnetic fields reduce the carbide percentage, which leads to an increase in the corrosion resistance of these samples in comparison with the deep cryogenically treated samples.     

Investigation on wear behaviour of cryogenically treated TiAlN coated tungsten carbide inserts in turning

Cryogenic treatment has been ascribed as a way of improving the cutting life of tungsten carbide turning inserts. Most of the research conducted till date has not reported any effort to excavate the effect of cryogenic treatment on the performance of coated tungsten carbide inserts in terms of adhesion strength of coatings deposited on tungsten carbide substrate. In order to understand the effect of cryogenic treatment on the adhesion strength of coatings, a comparative investigation of the wear behaviour and machining performance of cryogenically treated coated tungsten carbide inserts in orthogonal turning has been carried out in this study. The commercially available TiAlN coated square shaped tungsten carbide inserts (P25) were procured and subjected to cryogenic treatment at two levels −110 °C (shallow treatment) and −196 °C (deep treatment) of temperature independently. The criterion selected for determining the turning performance was based on the maximum flank wear (0.6 mm) as recommended in ISO 3685-1993. The results showed that shallow cryogenically treated coated tungsten carbide inserts performed significantly better as compared with deep cryogenically treated and untreated inserts. Major outcome of the present study includes a substantial decrease in tool life of deep cryogenically treated inserts as compared to untreated inserts indicating the destructive effect of deep cryogenic temperature (−196 °C) on TiAlN coated inserts which is further supported by VDI-3198 indentation test.