工程机械用ZGMn13Cr2高锰钢热处理工艺研究

对ZGMn13Cr2高锰钢进行1050℃×1 h水韧处理后,再进行(380～620℃)×1 h时效处理试验。通过OM、SEM、冲击试验、硬度测试和摩擦磨损试验等手段与方法,研究了不同温度时效处理对ZGMn13Cr2高锰钢组织及性能的影响。结果表明:在380～620℃时效,随着时效温度的升高,ZGMn13Cr2钢组织中的析出碳化物越来越多。540℃时效,试样组织中碳化物呈颗粒状,分布均匀。620℃时效,试样组织中碳化物大量析出并聚集长大。与仅进行水韧处理的ZGMn13Cr2钢试样相比,时效处理ZGMn13Cr2钢的硬度与耐磨性有所提高,韧性有所下降。经过1050℃×1 h水韧+540℃×1 h时效的ZGMn13Cr2钢的耐磨性最佳,其失重为28.3 mg,硬度和冲击功分别达到374 HB和84 J。     

ZGMn13TiRE钢履带板热处理工艺改进

研究了ZGMn13TiRE钢固溶过程中的组织变化,改进了ZGMn13TiRE钢履带板热处理工艺。结果表明,ZGMn13TiRE钢固溶阶段的组织变化包括珠光体分解和碳化物溶解两个过程,其中碳化物随固溶温度升高逐步发生溶解。与传统的一段加热固溶水韧处理工艺相比,采用二段加热固溶水韧处理工艺使ZGMn13TiRE钢履带板热处理受铸件成分差异影响较小;改进后的1050 ℃×40 min＋1100 ℃×40 min二段热处理工艺使ZGMn13TiRE钢履带板一次热处理合格率由原先的70%左右提高95%。     

机械振动振幅对消失模铸造ZGMn13钢组织和性能的影响

采用显微组织观察、硬度测试、室温冲击试验研究了不同振幅机械振动对消失模铸造ZGMn13钢组织和性能的影响。结果表明:浇注过程中施加振动,使ZGMn13钢中非金属夹杂物分布更加均匀、细小,晶粒明显细化,试样硬度和冲击吸收能量有所提高。振幅在0.3~0.6 mm内,随着振动振幅的增加, ZGMn13铸钢晶粒逐渐细化,硬度和冲击吸收能量逐渐提高。振幅0.6 mm时,硬度和冲击吸收能量达到最大值,分别为413HB和1.7J,比未振动的ZGMn13钢试样分别提高了27.9%(323→413HB)和21.4%(1.4→1.7J)。     

时效处理对ZGMn13钢组织和性能的影响

为优化ZGMn13钢的时效工艺,对ZGMn13钢进行了1 050℃×4 h水冷的水韧处理及分别在200～500℃保温2、6、10 h空冷的时效处理。随后采用光学显微镜、扫描电子显微镜和冲击磨损试验检测了钢的微观组织、冲击韧性和耐冲击磨料磨损性能。结果表明:随着时效温度的升高和时间的延长,ZGMn13钢中开始析出细小弥散的碳化物,硬度提高; 425℃时效10 h、450℃时效6 h和500℃时效2 h的钢中析出的碳化物级别达到了7级; 425℃时效的钢硬度最低,350℃时效的钢冲击韧性最高; 400℃时效的钢磨损率仅为0.32%,即耐磨性最佳。硬度与韧性的良好结合是钢的耐磨性改善的重要原因。     

“ZG28CrMnMo代替ZGMn13

我厂过去生产装载机的斗牙及刀片材料均为ZGMn13。该钢处理后的硬度不高于HB180～220。但强烈冲击和压力后,会产生冷加工硬化,其硬度可达HB450～550,具有了良好的耐磨性能。装载机的工况和工作介质表明其磨损是静载而不是动载磨损。因而不会产生加工硬化,耐磨性就较差。1979年以ZG35CrMo代替ZGMn13效果更差。经过研究与试制,确定了以ZG28CrMnMo来代替ZGMn13。一、ZG28CrMnMo钢的成分和性能 ZG28CrMnMo钢的化学成分列于表1,其热处理制度和机械性能列于表2。材料静载下的耐磨性能与硬度、韧性、     

ZGMn13钢辙叉与U71Mn钢钢轨闪光焊接接头组织

利用X射线衍射,金相和透射电镜分析方法,分析了ZGMn13钢辙叉和U71Mn钢钢轨加介质闪光焊接接头组织,结果表明,ZGMn13钢焊接热影响区内无碳化物析出,U71Mn钢接头无马氏体产生,介质熔合区内形成宽约50um的纳米晶组织,高锰钢熔合区存在少量应变诱发马氏体。     

高锰钢在模具制造中的应用

论述了ZGMn13的合金化机理、性能特点,讨论了模具钢的基本性能要求和ZG-Mn13在模具制造中的应用,介绍了ZGMn13的热处理方法。     

ZG80Cr2MnMoSi钢的回火特性及磨损机理

研究了淬火方式和回火温度对ZG80Cr2MnMoSi钢的组织、性能以及磨损特性的影响。研究结果表明:ZG80Cr2MnMoSi钢对淬火方式不敏感,具有良好的淬透性和淬硬性;试验钢经过870℃×2 h风冷+500℃×2 h回火处理,所获得基体的硬度明显高于传统钢ZGMn13强化后的硬度,获得的组织为回火屈氏体,其硬度为49 HRC,冲击韧度为33 J/cm2,耐磨性能好。     

Mn18Cr13NbN无磁不锈钢的形变强化

研究了Mn18Cr13NbN无磁不锈钢的形变强化工艺及所获得的力学性能.结果表明,冷变形和温变形均能使钢强化,且温变形较冷变形更容易控制.在强度相同的情况下,温变形的钢具有更好的塑韧性.经冷变形的钢回火可提高其塑韧性.     

纳米TiN粉末强化ZGMn13微观组织和力学性能的研究

采用氩气吹人法制备纳米TiN粉末强化ZGMn13样品,研究了纳米TiN对ZGMn13显微组织和力学性能的影响.结果表明,经纳米TiN粉末强化处理后的高锰钢的组织明显细化,力学性能明显提高.透射形貌分析和衍射花样标定得出:纳米级TiN以0.5916％的错配度存在于基体中,可作为异质形核剂细化高锰钢晶粒,强化基体,并分析了纳米TiN在高锰钢中的作用机理.     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

面向零件形状的计算机图形库的开发

论述了CAD技术中参数化设计的三种建模方法，重点介绍了基于特征的参数化建模原理。在此基础上，分析机械设计中的机构结构，归纳出其零件的几何特征构成。设计了机构CAD图形库，并提出了该图形库生成步骤和人机交互界面。     

FeCrAIW电弧喷涂层组织的致密化研究

采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.