共查询到20条相似文献,搜索用时 15 毫秒
1.
In this study, the effects of cryogenic and boronising treatments on the wear behaviour and microstructure of 1.2344 steel were evaluated. X-ray diffraction analysis and scanning electron microscopy were used to investigate the microstructure, percentage of the retained austenite, and the carbides' morphology. In addition, a micro-hardness test and pin-on-disk wear method were utilised to assess the samples’ wear resistance. The results showed that the use of a cryogenic treatment improved hardness and wear resistance by 25% and 39%, respectively, compared with a quenching - tempering heat treatment. In addition, cryogenic and boronising treatments improved hardness and wear resistance by 228% and 75%, respectively, compared with a quenching - tempering heat treatment. The improvement in the properties of cryogenically treated and boronised-cryogenised samples in comparison with the quenched-tempered ones is due to the transformation of retained austenite to martensite, precipitation of fine carbides, and better carbide distribution. Also, the formation of the Fe2B phase affected the properties of the boronised-cryogenised samples. Moreover, examining the wear levels revealed that the dominant wear mechanism is adhesive and tribochemical wear. 相似文献
2.
Kamran Amini Amin Akhbarizadeh Sirus Javadpour 《Journal of Materials Engineering and Performance》2016,25(2):365-373
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. 相似文献
3.
4.
Jun Wang Ji Xiong Hongyuan Fan Hong-Shan Yang Hao-Huai Liu Bao-Luo Shen 《Journal of Materials Processing Technology》2009,209(7):3236-3240
Effects of deep cryogenic treatment on the microstructure, hardening and abrasion resistance behaviors of 16Cr1Mo1Cu cast iron subjected to destabilization treatment were investigated. The results show that the cryogenic treatment can effectively reduce the retained austenite after destabilization heat treatment, but cannot make retained austenite transform completely. Cryogenic treatment can markedly improve bulk hardness and abrasion resistance of the high chromium cast iron. In the course of destabilization treatment and then cryogenic treatment, the amount of precipitated secondary carbide, M23C6, was more than that in air cooling. The additional fine secondary carbide precipitated during the cryogenics treat after destabilization heat treatment comparing with air cooling, is the main reason for the increase of the bulk hardness and wear resistance. 相似文献
5.
采用扫描电镜、力学性能试验机和腐蚀磨损试验机研究了热处理工艺对Cr15Ni2MnMoCuNbRE铸钢组织、力学性能和耐腐蚀磨损性能的影响。结果表明,试验钢经860 ℃处理后的组织为奥氏体+晶界网状碳化物,热处理加热温度升高,试验钢的组织和性能均得到不同程度的改善。当加热温度从860 ℃升至1000 ℃后,试验钢组织中晶界碳化物减少,形态改善,碳化物由晶界网状转变为细棒状,力学性能和耐腐蚀磨损性能显著提高。与加热温度860 ℃处理的试验钢相比,加热温度为1000 ℃处理的试验钢,其硬度和冲击吸收能量分别提高了5.9%和49.8%,达到了57.5 HRC和35.5 J,耐腐蚀磨损性能提高了1.88倍。 相似文献
6.
Tribological and mechanical properties of deep cryogenically treated medium carbon micro alloy steel
In this study, the effects of deep cryogenic treatment (sub-zero treatments at -196 °C) on the microstructural, mechanical, and tribological behaviours of commercial Vanadium-Titanium micro-alloyed 38MnVS6+Ti steel was investigated. The samples were quenched (conventionally heat treated), deep cryogenically treated and then tempered at 250 °C for 1 h. Deep cryogenic treatments were applied for three different soaking times (namely 8 h, 12 h, and 24 h). The effects of deep cryogenic treatment on the specimens were evaluated in terms of impact toughness, hardness, wear resistance, and microstructure. The results indicated that the application of longer deep cryogenic treatment times significantly improved wear resistance, and improved the hardness slightly (1 to 3 HRC). However, deep cryogenic treatment also reduced the impact toughness compared to that of the conventionally heat treated sample, due to the precipitation of carbides and increasing hardness. 相似文献
7.
S. Harsha D.K. Dwivedi A. Agarwal 《Journal of Materials Engineering and Performance》2008,17(1):104-110
This paper describes the influence of a post spray heat treatment on the microstructure, microhardness and abrasive wear behavior
of the flame sprayed Ni-WC (EWAC 1002 ET) coating deposited on the mild steel. Coatings were deposited by using an oxy-acetylene
flame spraying torch (Superjet Eutalloy L & T, India). The wear behavior of the coating was evaluated using a pin on disc
wear system against SiC abrasive medium of 120 and 600 grades at 5, 10, 15, and 20 N normal load. Results revealed that the
influence of normal load on wear is governed by the microstructure, hardness and abrasive grit size. The heat treatment increased
average microhardness of the coating. However, it was found that the hardness does not correctly indicate the abrasive wear
resistance of Ni-WC coating in an as sprayed and heat treated condition. The heat treatment of the coating improved its abrasive
wear resistance against fine abrasive medium while the wear resistance against coarse abrasive was found to be a function
of a normal load. At low-normal load (5 and 10 N) the heat treated coating showed lower-wear rate than as spayed coating while
at high-normal loads (15 and 20 N) heat treated coating was subjected to higher-wear rate than as sprayed coating. In general,
an increase in normal load increased the wear rate. The scanning electron microscopy study indicated that the wear largely
takes place by groove formation and scoring of eutectic matrix and the fragmentation of the carbide particles. 相似文献
8.
9.
10.
探究了不同深冷处理温度对M2Al高速钢高温耐磨性的影响。结果表明,经过深冷处理的M2Al高速钢试样微观组织发生了变化,残留奥氏体转变为马氏体,碳化物尺寸减小并且弥散分布在马氏体基体上。随着深冷温度的降低,碳化物的尺寸减小且分布均匀。M2Al高速钢经过深冷处理后高温摩擦因数比未深冷处理的减小,其中-160 ℃深冷处理试样的高温摩擦因数比未深冷处理的降低55.7%,经过深冷处理的M2Al高速钢磨损量比未深冷处理的减小,其中-160 ℃深冷处理后磨损量最小。未深冷处理的M2Al高速钢试样磨损形貌比较粗糙,发生严重的粘着磨损,经过-160 ℃深冷处理的试样,磨痕比较浅,磨损形式主要为磨粒磨损。当深冷处理温度为-160 ℃时,M2Al高速钢的高温耐磨性提升效果最好。 相似文献
11.
基于深冷处理提供的温度场和永磁体提供的匀强磁场,对42CrMo合金钢进行磁场深冷处理,并与常规工艺和深冷处理工艺进行了对比分析。结果表明:磁冷工艺在深冷处理工艺的基础上进一步提高了42CrMo钢的耐磨性,磁冷工艺处理材料的耐磨性较常规工艺和深冷工艺分别提高约26.7%和22.2%。这是由于深冷处理使得残留奥氏体进一步转化为马氏体;深冷处理也使得过饱和马氏体析出大量碳生成碳化物;深冷处理中磁场的存在对α-Fe晶格的作用使过饱和马氏体析出碳的方向得到优化,回火屈氏体在磁场方向致密聚集,耐磨性提高。 相似文献
12.
深冷处理对硬质合金的影响 总被引:2,自引:0,他引:2
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。 相似文献
13.
Cutting tool costs is one of the most important components of machining costs. For this reason, tool life should be improved using some methods such as cutting fluid, optimal cutting parameters, hard coatings and heat treatment. Recently, another one of the methods commonly used to improve tool life is cryogenic treatment. This study was designed to evaluate the effects of different holding times of deep cryogenic treatment on tool wear in turning of AISI 316 austenitic stainless steel. The cemented carbide inserts were cryogenically treated at −145 °C for 12, 24, 36, 48 and 60 h. Wear tests were conducted at four cutting speeds (100, 120, 140 and 160 m/min), a feed rate of 0.3 mm/rev and a 2.4 mm depth of cut under dry cutting conditions. The wear test results showed that flank wear and crater wear were present in all combinations of the cutting parameters. However, notch wear appeared only at lower cutting speeds (100 and 120 m/min). In general, the best wear resistance was obtained with cutting inserts cryogenically treated for 24 h. This case was attributed to the increased hardness and improved micro-structure of cemented carbide inserts. These improvements were confirmed through hardness, image processing, and XRD analyses. 相似文献
14.
通过改变深冷处理温度和时间,研究了不同深冷处理工艺对T10A钢力学性能和耐磨性能的影响。研究表明:深冷处理对T8A钢的强度和冲击韧性影响较小,但能提高T8A的硬度和耐磨性;不同工艺处理后硬度均能提高1 HRC左右,提高耐磨性的最佳处理工艺为-150℃保温6 h,其处理后耐磨性比未深冷提高了86%。 相似文献
15.
16.
冷处理对Cr12MoV钢硬度的影响 总被引:1,自引:0,他引:1
测定不同热处理条件下Cr120MoV钢的硬度 残留奥氏体量,并进行金相和透射电镜观察发现,钢中的残留奥氏体和下贝氏体组织对冷作模具钢的耐磨性有不利影响。采用冷处理可以抑制下贝氏体转变,显著提高Cr12MoV钢的硬度和耐磨性能。 相似文献
17.
Simranpreet Singh Gill Jagdev Singh Rupinder Singh Harpreet Singh 《Journal of Materials Engineering and Performance》2012,21(7):1320-1326
This study aims to present the metallurgical and mechanical characterization of cryogenically treated AISI M2 high speed steel (HSS) in terms of carbide precipitation and wear behavior. The samples of commercially available conventionally quenched and tempered AISI M2 HSS were procured and subjected to cryogenic treatment at two levels ?110?°C (shallow treatment) and ?196?°C (deep treatment) of temperature. The microstructures obtained after cryogenic treatments have been characterized with a prominence to comprehend the influence of cryogenic treatment vis-à-vis conventional quenching and tempering on the nature, size, and distribution of carbides. The mechanical properties such as hardness and wear rate of the specimens have also been compared by performing Rockwell C hardness test and pin-on-disc wear test, respectively. Microstructures, hardness, wear rate and analysis of worn surface reveal the underlying metallurgical mechanism responsible for the improving mechanical properties of the AISI M2 HSS. 相似文献
18.
19.
分别采用X射线衍射(XRD)、电子透射电镜(TEM)和磨损测量(WT)等方法研究了深冷处理对高铬铸铁显微组织和磨损行为的影响。深冷处理能有效地降低高铬铸铁中的残余奥氏体含量,促进细微碳化物的析出,但不能完全将奥氏体转化为马氏体。大量马氏体的形成和微小二次碳化物的析出,显著提高了高铬铸铁的耐磨性。当残余奥氏体含量约为15%时,材料的耐磨性能达到最好,残余奥氏体量较多或较少都不利于耐磨性的提高。结果表明,亚临界加深冷处理试样的磨损性能较未深冷的试样有较大的提高。 相似文献