关于模具钢的预备热处理

大量的文献资料介绍了预备热处理(包括亚温淬火与高温回火)对最终处理后的变形和机械性能的影响。但是,对于热作模和压铸模而言,主要采用耐热模具钢并经渗氮处理。而文献资料中几乎未介绍预备热处理对模具钢渗氮后的变形和抗热龟裂性的影响。因此,本文的目的就是研究预备热处理对经整个热处理和化学热处理周期(锻造、退火、预备热处理、淬火、高温回火、渗氮)后模具钢综合性能的影响。选择目前广泛使用的渗氮模具钢4Cr5MoVSi钢进行研究,其化学     

离子渗氮的工艺因素对马氏体时效钢性能的影响

金属在辉光放电中渗氮是金属件的效率最高和效果最好的化学热处理方法之一。采用在辉光放电等离子体中渗氮代替普通气体渗氮来表面强化马氏体时效钢是有发展前途的。我们研究了离子渗氮的工艺因素对03X12H10MT和06X15H6MBφБ马氏体时效钢的组织与性能的影响。上述牌号钢的试样在渗氮前进行了热处理:淬火并高温回火。经过这种处理后钢的组织是铁素体,残余奥氏体(达20％)和高度弥散Ni_3Ti,Fe_2Mo型金属间夹杂物。离     

38CrMoAl钢的介稳态气体渗氮的组织与硬度研究

通过与调质处理比较,研究淬火-分配与盐浴淬火两种介稳态预备热处理对38CrMoAl钢渗氮后组织与硬度的影响。利用金相显微镜、显微硬度计和X射线衍射仪对渗氮层进行分析。结果表明：介稳态渗氮试样渗氮层的硬度高于常规调质渗氮层。在同一气体渗氮条件下,介稳态渗氮后化合物层厚度与渗氮层深度大于调质后渗氮的渗层。预备热处理状态对渗氮后试样表面相的组成几乎没有影响。     

高性能机械零部件的复合热处理

随着制造业的持续发展,对机械零件的性能要求也越来越严格,单一的热处理工艺已不适用于高性能要求的零件,需采用复合热处理工艺,即由两种或多种热处理工艺,热处理与相关工艺按功能继承和优质经济的原则组合的工艺。目前应用的复合热处理工艺有:①多种热处理方法复合;②涂(镀)覆与热处理复合;③形变热处理;④整体或表面强化与表面形变强化复合。简述了下列复合热工艺的应用实例:节能降耗的复合热处理,渗氮或氮碳共渗后淬火,化学热处理与淬火回火复合,渗氮或氮碳共渗与氧化处理复合,表面改性与热处理复合,以及强韧化处理的复合,等。     

38CrMoAl钢介稳态气体渗氮的组织与硬度

通过与调质处理比较,研究淬火-分配与盐浴淬火两种介稳态预备热处理对38Cr Mo Al钢渗氮后组织与硬度的影响。利用金相显微镜、显微硬度计和X射线衍射仪对渗氮层进行分析。结果表明:介稳态渗氮试样渗氮层的硬度高于常规调质渗氮层。在同一气体渗氮条件下,介稳态渗氮后化合物层厚度与渗氮层深度大于调质后渗氮的渗层。预备热处理状态对渗氮后试样表面相的组成几乎没有影响。     

钢的渗氮-加热淬火复合处理

本文简要地综述了钢件渗氮—再加热淬火复合热处理新工艺的原理、工艺过程和组织性能.     

9SiCr钢渗氮淬火复合热处理

渗氛淬火能使钢获得比单一渗氮或单一淬火更高的硬度、耐磨性和力学性能，具有广阔的应用前景。1试验材料和方法试验明9SiCr钢。硬度试样尺寸为φ15×10mm。热处理设备有IOOkW盐治炉、25kw低温回火炉、DS型低温箱和I，D－60kw离子渗氮炉。热处理工艺如表1所示。表面硬化区硬度用HVA－IOA型小负荷维氏硬度计测试，从表面起每磨去0．lmrn测量一次维氏硬度值。基体硬度用HRC－15OA洛氏硬度计测试。2试验结果门）淬火个冷处理上回火与淬火一回火后硬度比较gsiCr钢淬火十冷处理硬度同后淬火后再经150、18O和2（）OC回火后的硬度比较，…     

瓦楞辊的表面强化工艺

研究了经渗氮、碳氮共渗后高频淬火处理后42CrMo及45钢瓦楞辊试样的表面组织和力学性能。结果表明,两种试样经渗氮加高频淬火处理后表层主要为氮化物和回火马氏体组织;碳氮共渗加高频淬火处理后试样表层组织主要为回火马氏体和有少量氮化物。45钢和42CrMo钢试样经过处理表面硬度分别达到740和800 HV0.1,经高频淬火处理后,试样表面硬化层有较好的硬度梯度。     

等温淬火球铁(ADI)的热处理和质量控制

1等温淬火球铁（ADI）的热处理1．1等温淬火热处理是生产ADI的必要条件球墨铸铁由于石墨呈球状对金属基体的切割作用小,所以金属基体的性能特点对球铁的性能影响很大。普通球铁的金属基体多为珠光体或铁素体,而经过等温淬火热处后的ADI典型的金属基体是针状铁素体和富碳奥氏体（这种组织国际上通称为奥铁体）。     

H13钢热锻模具的真空热处理

根据实际生产,对H13热锻模具钢的真空淬火+回火和表面离子渗氮热处理工艺进行了探讨。结果表明:H13热锻模具钢经此工艺处理后,具有较高的硬度和热疲劳性能,延长了模具的使用寿命。     

Electron meets nitrogen: combination of electron beam hardening and nitriding

Abstract

Combined heat treatments, also known as duplex or hybrid technologies, offer new structure/property relationships in layered matrix compounds. The treatment sequence is critical. There are within reach both properties and property gradients that are impossible to achieve using the respective single treatment processes alone nor by simple addition of the effects of the single processes. Good technical progress is given by the combination of thermochemical treatment with high energy beam surface hardening, in particular electron beam hardening. After a historical survey (milestones) of the combination of thermochemical with thermal (surface) heat treatment technologies, the paper deals with the principles of the combining electron beam hardening after nitriding and vice versa , electron beam hardening before nitriding and the effects on microstructure and properties. Typical examples of industrial application are discussed. In this field of heat treatment, further development is focused on combinations of high energy beam hardening (electron or laser beam) with hard coating.     

Application of Electron Beam Surface Technologies in the Automotive Industry

Progress in the beam deflection technique opens up new possibilities for the application of electron beam (EB) surface and welding technologies in the automotive industry. This development is based on three-dimensional high-speed beam deflection and fully automatic online process control. So, in the EB surface treatment three-dimensional energy transfer fields can be realised which take into account the contour of a component, the conditions of heat conduction and the load conditions. High flexibility, precision and reproducibility are typical characteristics. High productivity is achieved by the simultaneous interaction of the EB in several processing areas or by carrying out several processes simultaneously. EB surface treatment is becoming more and more attractive and important especially in the automotive industry, and also in comparison to laser technologies. This paper deals with different EB surface technologies, for example hardening,remelting, surface alloying, dispersing or cladding of different materials such as steel, cast iron and different alloys of Al,Mg and Ti. Examples of applications in the automotive industry, especially engine components, will be discussed.     

稀土化学热处理进展

综述了哈尔滨工业大学稀土化学热处理研究和应用成果。包括稀土渗碳及碳氮共渗、稀土渗氮及氮碳共渗、等离子体稀土渗氮、稀土渗硼及硼铝共渗、稀土多元共渗、稀土渗金属工艺技术，稀土的催化和微合金化机制，渗层组织和性能的改善，稀土化学热处理在生产中的应用及其过程的数学模型与计算机仿真等。     

Combination of coating and heat treatment processes

For a proper use of coated tools and components excellent coating properties as well as excellent substrate properties of the coating/substrate composite are necessary. A well known example is the load support of hard steel substrates for thin wear resistant coatings. Therefore coating processes must be combined with heat treatment processes of the substrates, whereby several practical processing constraints like order and compatibility of the applied treatment procedures must be considered. The combination of CVD-coating plus laser beam hardening is an example of a post coating heat treatment. Applications may be possible for large forming tools made of high alloyed tool steels, which nowadays are usually through hardened after CVD-coating. Laser beam hardening offers the possibility, to harden only the highly loaded edges of the tools. The advantages of this combination are short process time, less distortion and compressive residual stresses in the substrate surface. CVD-coatings can endure laser beam hardening with suitable parameters. The influence of CVD TiN-coated steel substrates and laser beam hardening parameters on microstructures and properties of coating/substrate compounds have been investigated. Special attention was paid to overlapping hardening zones, which may occur at the start and end points of a laser hardened track. In summary, the combination of coating and heat treatment processes show a high potential to produce coating/substrate compounds with excellent coating properties as well as excellent substrate properties.     

Influence of initial heat treatment of 17-4 PH stainless steel on gas nitriding kinetics

Results of the investigation of nitrided layers on 17-4 PH type precipitation hardening stainless steel are presented in this paper. The layers have been produced in the process of gas nitriding in a partly dissociated ammonia at temperatures between 410 and 570 °C. Hydrogen chloride admixture to active atmosphere was used as a surface activator. Structure of the nitrided layers were examined using scanning and transmission electron microscopy, X-ray microanalysis (EDX and WDX), and X-ray diffraction. The influence of the initial steel heat treatment on the nitriding kinetics has been considered. 17-4 PH stainless steel was nitrided at various heat treatment conditions, i.e. after solution treatment or ageing at different temperatures. The influence of precipitation processes taking place during the heat treatment before nitriding on the diffusive process kinetics was proven. It was found that, that increasing of steel ageing temperature up to 600 °C before nitriding effects on an increasing of the nitriding kinetics.     

Hard coatings on thermochemically pretreated soft steels: application potential for ball valves

The combination of a thermochemical heat treatment (e.g., nitriding or carburizing, with or without plasma enhancement) and a hard coating [e.g., titanium nitride (TiN), chromium nitride (CrN) or amorphous hydrogenated carbon (a-C:H)] is known as “duplex treatment”. It offers the possibility to improve the functional properties of tools and machine parts compared with a single treatment. The combination of plasma nitriding and physical vapour deposited hard coating has been investigated by various groups, mostly for increasing the wear resistance of tools. However, machine parts and precision components are also very promising candidates for duplex treatments, especially when they are made of soft steels such as stainless steels. This paper shows that the functional behaviour of duplex-treated parts is determined both by the application-oriented optimization of the thermochemical heat treatment and by selection of the appropriate hard coating. The hard coatings include TiN, chromium-containing amorphous hydrogenated carbon (a-C:H:Cr) and “pure” a-C:H. For demonstration purposes, this paper focuses on the ferritic stainless valve steel X20Cr13.     

Substrate Strengthening of CVD Coated Steels

CHEMICAL VAPOR DEPOSITION is successfullyused in production since decades to enhance the wearresistance of tools.Excellent coating properties areachieved with relatively simple equipment.The highdeposition temperatures used for CVD favor a goodadhesion of CVD coatings on the substrate,but alsonegatively influence the properties of the steelsubstrates.High coating temperatures followed byrelatively low cooling rates demand a subsequent heattreatment to restore the properties of the s…     

渗氮处理在重载齿轮上的应用进展

目前重载齿轮常用的表面热处理工艺有渗碳淬火、感应淬火以及渗氮处理等,渗氮处理由于畸变小、工序简单等优点在工业生产上具有很大的优势和广阔的应用前景。通过增加渗层深度以及提高基体硬度能够有效提高渗氮齿轮的承载能力,从而扩大渗氮处理在重载齿轮上的应用。介绍了渗氮处理对齿轮的接触疲劳强度和弯曲疲劳强度的影响,以及基体性能对渗氮工艺的影响,回顾了渗氮齿轮的研究进展,如渗层可控离子渗氮、稀土催渗、时效硬化渗氮钢等,指出提高渗氮齿轮承载能力的途径为,深入进行渗氮齿轮的基础性研究,提高渗氮过程控制水平以及积极开发新工艺等。     

Influence of Surface Preparation on the Kinetics of Controlled Gas-Nitrided AISI H13 Steels Used in Extrusion Dies

In the aluminum extrusion practice, gas nitriding represents an important factor in enhancing the service life of AISI H13 steel dies. It is observed that if the die-bearing surface is not adequately prepared before nitriding, a nonuniform and shallow nitrided layer develops with reduced hardening effect. The focus of this paper is to investigate the influence of different surface conditions in terms of roughness on the kinetics of nitrided layer developed during gas-nitriding process under controlled nitriding potential. Four samples made of AISI H13 steel properly heat treated (quenched and tempered) were considered: without surface preparation, ground, polished, and lapped. All the samples were gas nitrided under the same conditions and examined after being nitrided. The nitrided layers were characterized using different techniques including optical microscopy, scanning electron microscopy, x-ray diffraction analysis, energy dispersive spectrometry mapping, and microhardness analysis. It was found that the surface preparation prior to nitriding significantly enhanced the nitriding kinetics, which in turn resulted in even and deep nitrided case depth. This provided high load-bearing capacity due to increased and deep hardening effect as compared to unprepared sample. A thinner and uniform compound layer with well-resolved phases was achieved in comparison with unprepared sample.     

电子束局部热处理对30CrMnSiNi2A钢接头组织和断裂性能的影响

一般电子束焊接接头在焊后都需要进行真空或炉中整体热处理,以改善接头的组织和性能。电子束局部热处理是一种新型的热处理方式,具有精确度高、灵活性好、效率高、节省能源和提高生产率的优点。因此探讨该热处理方式对电子束焊接接头组织、力学性能和断裂韧性的影响规律,具有十分重要的实际意义。本文结合金相组织分析,对30CrMnSiNi2A钢电子束焊接后焊态、焊后炉内整体热处理和电子束局部热处理三种焊接接头不同区域的力学性能和断裂韧性进行了探索性试验研究。试验结果表明,电子束局部热处理能够在一定程度上改善焊接接头的组织和断裂性能,特别是能够明显改善焊缝的断裂韧性,但还不能完全替代整体热处理,仍需要今后继续探索其更为合理的处理方式和工艺。