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高合金钢热冲孔冲头寿命关系到模具与产品成本、生产效率、自动化设备的使用,因此,应注重冲头的选材、材料制备与冲头制造工艺。 用 3 Cr3Mo3 VNb 作为高合金钢热冲孔冲头,为提高模具寿命,在材料制备上,优化了成分,采用电渣重熔冶炼,减少杂质,毛坯锻造两次,用大锻造比锻造,冲头热处理用真空炉,三次回火,热处理硬度取 HRC42 ~ 46 ,冲头表面处理采用镀铬工艺,开展了热冲孔工艺试验。 结果表明,用3 Cr3Mo3 VNb 可使冲孔冲头寿命平均达到 800 件以上。 相似文献
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目的 为了提高摆线液压马达内花键输出轴零件的加工效率及材料利用率、降低生产成本,提出一种冷精密成形的工艺与模具。方法 首先分析了摆线液压马达内花键输出轴的形状特点,初步制定了三工序冷挤压成形工艺:正挤细杆—反挤深孔—反挤花键孔,并通过数值模拟和实物实验对该成形工艺进行分析验证。在工艺实验中发现,采用线切割方法加工的第3序通体花键形状冲头,在与冲头套下端面交界处极易发生断裂。因此对花键冲头的结构和加工方法进行了调整,将冲头整体设计为圆柱台阶状,头部采用电火花加工方法加工一段花键形状,花键与圆柱部分采用锥角过渡。结果 实验结果显示,锻件成形工艺稳定,成形锻件精度较高,改进后的冲头寿命较高。结论 内花键输出轴成形工艺可行,改进的冲头结构降低了冲头产生应力集中的风险,提高了抵御偏载力的能力,成形工艺与模具满足了批量生产的考核。 相似文献
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目的研究超高强度钢DP1000液压成形A柱仿真技术和试验效果,解决批量生产中DP100焊管技术和同步冲孔等关键技术。方法基于Autoform有限元模拟软件,仿真分析了DP1000液压成形A柱的可行性,试验了DP1000液压成形A柱零件。通过对比高频焊管和激光焊管的液压成形零件焊缝质量,解决量产零件开裂问题,开展了DP1000液压成形A柱的Cr12MoV、ASP30和SKH51不同材料的同步冲孔效果,解决DP1000材料冲头寿命和冲孔质量问题。结果采用DP1000材料可以获得液压成形A柱,具有制造可行性。与高频焊管相比,具有较小的热影响区和硬度变化较小的激光焊管,更适合DP1000液压成形A柱使用。结论 ASP30和SKH51比传统的Cr12MoV更适合于DP1000材料液压成形A柱同步冲孔,冲头寿命提高80多倍,冲孔质量良好。 相似文献
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模壁润滑温压工艺的研究 总被引:3,自引:0,他引:3
对模壁润滑温压工艺进行了较为系统的研究,分析了温度、粉末中润滑剂添加量、模壁润滑剂种类及其浓度等对温压效果的影响.结果表明,粉末温度在100℃时温压效果最好;Fe-1.5Cu-0.5C粉末中添入0.2%内润滑剂时效果最好,而Fe-1.5Ni-0.5Mo-0.5Cu-0.5C粉末中最佳润滑剂含量为0.3%;模壁润滑剂A、B分别适合于较低和较高压制压力条件,2种模壁润滑剂均在浓度低时温压效果较好;在686MPa时,Fe-1.5Cu-0.5C和Fe-1.5Ni-0.5Mo0.5Cu 0.5C粉末分别获得了7.48、7.39g/cm3的压坯密度;模壁润滑温压工艺较适用于压缩性良好的粉末,对压缩性较差的粉末没有优势;模壁润滑工艺的脱模压力比内润滑工艺小35%~45%,可以减少模具损耗. 相似文献
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R. Tsaryk K. Peters R. E. Unger M. Feldmann B. Hoffmann F. Heidenau C. J. Kirkpatrick 《Journal of the Royal Society Interface》2013,10(86)
Cobalt-based materials are widely used for coronary stents, as well as bone and joint implants. However, their use is associated with high corrosion incidence. Titanium alloys, by contrast, are more biocompatible owing to the formation of a relatively inactive titanium oxide (TiO2) layer on their surface. This study was aimed at improving Co28Cr6Mo alloy cytocompatibility via sol–gel TiO2 coating to reduce metal corrosion and metal ion release. Owing to their role in inflammation and tissue remodelling around an implant, endothelial cells present a suitable in vitro model for testing the biological response to metallic materials. Primary human endothelial cells seeded on Co28Cr6Mo showed a stress phenotype with numerous F-actin fibres absent on TiO2-coated material. To investigate this effect at the gene expression level, cDNA microarray analysis of in total 1301 genes was performed. Compared with control cells, 247 genes were expressed differentially in the cells grown on Co28Cr6Mo, among them genes involved in proliferation, oxidative stress response and inflammation. TiO2 coating reduced the effects of Co28Cr6Mo on gene expression in endothelial cells, with only 34 genes being differentially expressed. Quantitative real-time polymerase chain reaction and protein analysis confirmed microarray data for selected genes. The effect of TiO2 coating can be, in part, attributed to the reduced release of Co2+, because addition of CoCl2 resulted in similar cellular responses. TiO2 coating of cobalt-based materials, therefore, could be used in the production of cobalt-based devices for cardiovascular and skeletal applications to reduce the adverse effects of metal corrosion products and to improve the response of endothelial and other cell types. 相似文献
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Boron atoms were implanted into W6Mo5Cr4V2 high-speed steel (HSS) in CC-60 ion implantation machine to improve its tribological properties. The influence of boron implantation dose on the microhardness, friction coefficient and wear resistance of HSS were investigated. The experiment results showed that the implantation of boron can improve the tribological properties of W6Mo5Cr4V2 steel greatly. Then the phase and composition of implanted layer were analyzed by XRD and XPS. The analysisresult revealed that the interface between the implantation layer and substrate appeared to be mixed.With the increase of boron dose, the compound of δ-WB, CrB, BFe3 are the main additive phases, which supposed to be the main reason to improve the tribological properties of W6Mo5Cr4V2 steel. 相似文献
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通过分析影响ZG06Cr13Ni4Mo不锈钢材料韧脆转变温度的因素,表明δ-Fe是降低此材料的抗低温冲击能力的主要原因。对此材料进行优化,减少δ-Fe含量,使材料具有良好的抗低温冲击能力。随后通过扫描电镜得到低温冲击试样断口形貌,显示此材料在极低的温度下仍保留良好的韧窝状韧性断口形貌,随温度降低,冲击断口会呈从完全韧窝状变成韧窝-解理状,再到完全解理状的变化规律。 相似文献
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采用热压烧结工艺制备了添加微量Cr3C2的Ti(C0.5N0.5)-(Ni-Co)-Mo2C-Cr3C2系Ti(C,N)基金属陶瓷。分析三种不同Mo2C含量材料的力学性能、断口形貌和磨削表面压痕裂纹扩展情况,研究表明:材料的断裂均以沿晶断裂为主;材料的抗弯强度与Rim相有关,8wt%Mo2C含量的金属陶瓷Rim相厚度适中,抗弯强度高;0.6wt%Mo2C含量的金属陶瓷的扩展裂纹短,裂纹扩展发生偏转,断裂韧性高。 相似文献
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In consideration of good results about the application of deep cryogenic treatment (DCT) on materials, the effect on the microstructure and properties (hardness, toughness and the content of retained austenite) of a new developed cold work die steel (Cr8Mo2SiV) was examined. The execution of the deep cryogenic treatment in different processes showed a varying effect on materials. It was shown that the hardness of the DCT specimens was higher (+0.5HRC to +2HRC) whereas the toughness was lower when compared with the conventionally treated specimens (quenching and tempering). Following the DCT process retained austenite transformed into martensite, however, not completely. 相似文献
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激光熔敷钴合金涂层的抗空蚀和冲刷磨损性能 总被引:2,自引:0,他引:2
采用激光熔敷方法在20SiMn低合金钢表面制成了Co合金涂层,以两种目前水轮机转用材20SiMn低合金钢和0Cr13Ni5Mo不锈钢作为对比材料,对涂层进行了空蚀,液固两相流冲刷磨损及空蚀和冲刷磨损联合作用实验,采用失重法并结合能谱分析,X射线衍射分析及显微硬度测量等手段研究了涂层的显微结构和在不同形式损伤下涂层的性能并分析了原因。结果表明:在20SiMn低合金钢表面激光熔敷形成的Co合金涂层有良好的抗空蚀性能,这与涂层在空蚀过程中发生的应力诱发马氏体相变密切相关。良好的抗空蚀性能有利于提高涂层抗空蚀和冲刷磨损联合破坏,从而使涂层表现出与0Cr13Ni5Mo不锈钢接近的抗联合损伤性能。 相似文献
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介绍了一种在Q235钢表面进行等离子合金化及热处理工艺,获得表面高性能强化层的技术方法.通过该技术方法的处理,使Q235钢表面含有Mo,Cr,C合金元素,成分达到或接近冶金高速钢.该工艺技术的基本原理是在真空容器中,利用辉光放电的溅射现象,首先在Q235钢表面渗入合金元素Mo,Cr,表面含量分别达到12%(质量分数,下同)和4%左右,随后进行超饱和渗碳,使表面含碳量达到2.0%以上,合金化层成分接近钼系高速钢.合金层中的碳化物细小、均匀、弥散,无粗大的共晶莱氏体组织.Q235钢表面合金化后分别采用淬火 低温回火,淬火 2h深冷处理 低温回火两种工艺.结果发现,经深冷处理的试样表面硬度达到1600HV,明显高于未经过深冷处理试样的表面硬度.摩擦磨损实验表明,经深冷处理试样的滑动摩擦系数较未经深冷处理试样的要小,经深冷处理试样的耐磨性是未经深冷处理的1.6倍. 相似文献
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《Materials at High Temperatures》2013,30(3):117-129
AbstractThe results of a series of creep tests on the materials of CrMoV weldments, in main steam pipes, are presented in this paper. The tests were performed at 640°C, using uniaxial, notched, impression and cross-weld creep test specimens. The materials involved include service-aged and ‘as-new’ 1/2Cr1/2Mo1/4V parent materials, service-aged and new 2 1/4Cr1Mo weld metals and the HAZ materials in the new, service-aged and fully repaired welds. Based on the test data obtained, material constants in creep continuum damage constitutive equations for the parent, weld and HAZ materials were determined. Direct comparison of the test data allows the creep deformation and rupture behaviour of the parent, weld and HAZ materials to be identified. The material properties of these CrMoV weldment materials can be used in numerical FE modelling to contribute to the understanding of the performance of the new, service-aged and repaired welds in similar materials. 相似文献