RW40钢结硬质合金热挤压模具材料的研制

本文介绍了RW40钢结硬质合金热挤压模具材料的组成范围、制取工艺及物理机械性能;讨论了淬火、回火温度对合金组织和性能的影响。使用结果表明,该材料用作铝合金异形型材热挤压模具的寿命比传统的热作模具钢3Cr2W8V提高多倍,效果良好。     

硬质合金模具在冶金工业中应用的进展

本文介绍了硬质合金的性能，对硬质合金模具在冶金工业中的应用现状进行了详细论述，并指出在冶金工业中用硬质合金模具取代普通金属模具，可使模具寿命大幅度提高。在冶金工业生产中推广应用硬质合金模具具有较好的经济效益，前景良好。最后对扩大硬质合金模具在冶金工业中的应用提出了今后研究中值得注意的几个问题。     

硬质合金钢在钢包砖模具上的应用

对模具衬板选材、设计、制作,模具装配及使用等方面介绍了硬质合金钢在钢包模具上的应用,并对其使用效果进行了分析。     

粗晶硬质合金的研究现状及其发展前景

粗晶硬质合金具有特殊性能和用途，尤其是高温粗晶硬质合金具有结构缺陷少、显微硬度高、微观应变小等一系列优点，因此被广泛应用于矿山工具、冲压模具、石油钻采、硬面材料等领域。综述了国内外粗晶硬质合金的研究进展。介绍了其增韧耐磨机理和制备粗晶WC粉末的主要方法。     

超塑性在钛合金压力加工和焊接方面的应用

简要介绍了超塑性在压力加工方面以及相变超塑性在焊接方面的应用。重点介绍了超塑性成形和超塑性成形/扩散焊接技术在钛合金上的应用、超塑成形模具材料选择的原则、以及提高SPF部件性能的措施。     

硬质合金枪钻毛坯的制造

硬质合金枪钻毛坯的制造李秀莲（陕西渭河精密工模具总厂,岐山７２２４０５）硬质合金枪钻是加工深孔用的切削工具,目前有着很好的销售市场。硬质合金枪钻由硬质合金毛坯和钢柄焊接后经机械加工制成。其规格多,形状复杂,毛坯的成形难度比较大。本文主要介绍规格从４５...     

专利题录和文摘

<正> 特开平02097640 粘结相中含钴和(或)镍和碳化铬和碳化钨颗粒的适做精密模具的硬质合金 Cemented carbide for precision mould——has binder phase of Co and/or Ni and Cr carbide and W carbide grains TOSHIBA TVNGALLOY KK 1988.10.3     

ICP-OES法测定碳化钨中的高含量铬

碳化铬作为一种纳米硬质合金晶粒抑制剂,对硬质合金的生产有重要的影响,准确测量掺杂碳化钨中碳化铬含量有着重要的意义。掺杂碳化钨中碳化铬含量的测定目前主要采用的方法是先测其铬含量,再通过计算得出碳化铬含量。实验采用电感耦合等离子体发射光谱仪(ICP-OES)测定碳化钨中的掺杂铬含量,样品用浓硫酸、浓磷酸、混合酸(3体积浓硝酸+1体积浓磷酸)在电热板上消解,高纯碳化钨做基体配制标准工作曲线。进行了精密度和准确度实验,结果表明:该方法与传统方法相比准确性好、精密度高、快速便捷,能满足碳化钨中高含量铬的快速检测。     

用镍基合金作粘结相的特种硬质合金模具材料

介绍了WC-Ni与Cr_3C_2-Ni系特种硬质合金模具材料的发展、性能特点及其应用情况,列出了一些厂家生产的典型牌号合金的性能,指出随着现代工业的发展与合金性能的改善,这两类合金的应用领域将会进一步扩大。     

基于增材制造的硬质合金粉末研究现状

硬质合金是由难熔金属碳化物（WC,TiC,NbC等）和金属粘结相（如Fe,Ni和Co）组成,通过粉末混合、压制然后烧结而成。然而传统的粉末冶金成形方法模具成本高,难以形成复杂零件。相比之下,增材制造（3D打印）采用数字化叠层加工技术,能够实现快速精准的成形。研究与开发适于增材制造的硬质合金粉末是其中的关键一步,目前,增材制造的硬质合金粉末制备方法主要分为以下4类:机械合金化法、球形WC粉末表面包覆技术、喷雾干燥技术、等离子体球化技术,这4种方法在制备原理、成本和成形方法的灵活性上均有所不同。因此,综述了适用于增材制造成形的硬质合金粉末的4种制备方法,并对制备粉末的特性以及成形性能进行了对比,总结了粉末制备原理、各自的优缺点以及适用的增材制造成形工艺,希望可以推动增材制造成形硬质合金的研究发展。     

Comparison of the Activation Energies of the Formation of Chromium Carbide Coating on Carburized and Uncarburized AISI 1020 Steel

Chromium carbide coatings deposited by the salt bath method have a lot of technologically interesting characteristics. This method produces hard, wear–resistant, oxidation and corrosion–resistant coating layers on steel substrates. In the present study, the kinetics of chromium carbide formation on carburized and uncarburized AISI 1020 steel substrates has been compared. The presence of the Cr₇C₃ phase on the surface of steel substrates was confirmed by X‐ray diffraction. Cross–sectional observation of optical and SEM images showed that chromium carbide layers formed on the steel substrates were rather compact and smooth. The kinetics of chromium carbide coating by salt bath immersion indicated a parabolic relationship between carbide layer thickness and treatment time. The activation energy of the formation of carbide on the surface of carburized and uncarburized steel was calculated to be 87.9 and 225.6 kJ/mol, respectively. Moreover, an attempt was made to present contour diagrams for predicting the thickness of the chromium carbide layer. In addition, the possibility of establishing and using some mathematical relationships between process parameters and chromium carbide layer thickness was investigated.     

Mechanical properties of heterogeneous-structure wear-resistant high-chromium powder materials

Studies have been made on the effects of the production technology and composition of the initial material on the microstructure and some properties of powder materials having high chromium contents, which have heterogeneous structures. The materials were prepared from mixtures of iron powder and finely divided chromium and chromium carbide Cr₃C₂. The materials have a high wear resistance and also good mechanical characteristics and high resistance to corrosion in fresh water and sea water.     

水力喷射器高铬铸铁喷嘴与喉管的研制与应用

设计并制造了应用于水力喷射器的高铬铸铁喉管与喷嘴,金相检验表明,其铸态组织为细小均匀的圆形或六角形杆状（Cr,Fe）7C3型碳化物＋奥氏体,淬火＋回火后的组织为（Cr,Fe）7C3型碳化物＋回火马氏体＋少量残余奥氏体,H RC62～64。经装机试用,喷嘴使用寿命达20个月,比原用产品提高了13个月;喉管的使用寿命达10个月,比原用产品提高了5个月。     

Effects of heat treatment and counterface on the wear behaviour of Cr21 cast iron

The unlubricated sliding wear test of high chromium white cast irons (HCCIs) was conducted using a pin-on-disc configuration under different heat treatments and different hardnesses of the counterface. With the increase of counterface hardness (20?HRC–47?HRC–54?HRC), the mass loss of the sample first increases then decreases. When the counterface hardness is 20?HRC, adhesion wear mainly takes place between the high chromium cast iron and the surface of 1045 steel. When the hardness is 47 or 54?HRC, first HCCI’ matrix wear takes place, then carbide bump flakes under alternating stress. The mass loss of the counterface decreases with the increase of hardness for the same sample. The mass loss of quenching, once tempering and twice tempering sample decreases gradually for the same counterface hardness, but fluctuation of the samples’ surface increased. The disc material is always softer than the pin material and results in a severe wear regime operation.     

Reaction of tungsten carbide with oxides of refractory metals in a vacuum

Summary An investigation was made into the kinetics of the reaction of tungsten carbide with niobium, tantalum, vanadium, titanium, chromium, and zirconium oxides. Low-carbon alloys of tungsten with niobium, tantalum, chromium, and vanadium were produced. A method of preparing refractory alloys, using an oxide-carbide mixture as an intermediate product, has been proposed.     

Development of New Wear-Resistant Surface Coating at Elevated Temperature

Metal matrix composites containing a high vol-ume fraction of carbide particles are frequently usedas wear-resistant materials[1 -4]. For elevated tem-perature service in air ,the oxidation resistance andthe hot hardness of hard particle are the most i mpor-tant factors .In metal carbides ,tungsten carbide andchromiumcarbide can act as hard particles in metalmatrix in order to increase their hot hardness andthe ability of wetting metal matrix. Compared withtungsten carbide ,chromiumcarbide is …     

Production,Mechanical and Tribological Properties of Layered Composite Materials Based on a Chromium Carbide Alloy

Layered materials have been produced by joining hard surface layers of chromium carbide alloys to a less expensive substrate of steel. This method provides a substantial increase in the hardness and tribological properties of the composites, economizes on the use of expensive refractory materials, and decreases manufacturing costs. Composite layered materials of chromium carbide alloys can be recommended for the production of components which in addition to frictional wear are exposed to corrosive media and high temperatures.     

高碳铬钢凝固及热处理组织演变规律

摘要：系统研究了高碳铬钢复合轧辊工作层材质在凝固及热处理过程的组织演变规律。利用Thermo Calc软件进行平衡相图计算，阐明了平衡凝固过程及冷却过程中碳化物析出行为。通过热膨胀仪精确测定了奥氏体化温度对合金相变点的影响，获得了珠光体等温转变动力学曲线。结合扫描电镜、能谱分析和X射线衍射分析，确定了热处理工艺对最终显微组织的影响，明确了凝固过程中形成的一次碳化物M7C3和二次碳化物对热处理组织的影响规律，为高碳铬钢复合轧辊工作层材料的实际热处理工艺制定提供理论依据。     

Development of a technology of compaction of increased-density parts using gas drainage methods. IV. Compaction of powder materials without plasticizer

A new compaction method uses a porous female die made of powdered materials without plasticizer. Powders alloyed with carbon, nickel, chromium, molybdenum, and microtalc were used to produce the porous die. The powder was compacted by a special device, in which the operating surface of the matrix was lubricated through the open pores of the powdered material. Compaction of materials into a porous die ensures highly efficient drainage of gases from the press mold. As a result the density of iron-based compacts increases to 7.4–7.7 g/cm³ and in regard to mechanical properties the sintered materials can compete with those obtained by hot forging.     

高碳铬不锈轴承钢孪晶碳化物研究

研究了高碳铬不锈轴承钢“孪晶碳化物”（直线状和链状碳化物）的影响因素及形成原因,结果表明：加热温度达到1140℃,退火后开始出现沿晶界分布的链状碳化物;加热温度≥1160℃,退火后出现大量直线状和链状两种形态的碳化物。材料从高温直接冷却时,温度≥1080℃并且冷却速度≤80℃／h可能析出链状碳化物,并且温度越高冷却速度越慢析出的可能性就越大。直线状碳化物形成原因为：材料加热温度过高．晶粒长大的过程中晶界迁移时偶然发生堆垛错误形成了生长孪晶,在随后的退火过程中碳化物向奥氏体挛晶界面沉淀而形成,是真正意义上的孪晶碳化物。链状碳化物是由于材料过热或者局部过热,在随后冷却过程中碳化物沿奥氏体晶界析出而形成的,本质上是一种网状碳化物。