共查询到19条相似文献,搜索用时 187 毫秒
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采用热浸镀技术在Q235钢板表面制备了镀锌层,研究了浸镀时间对镀锌钢板拉伸性能的影响,通过扫描电镜观察了拉伸断裂后镀层表面、截面和断口处的形貌,分析了镀层的断裂机理。结果表明:与基体相比,Q235钢板热浸镀锌后的抗拉强度和塑性变形能力均下降;镀件抗拉强度的下降是由表面镀锌层强度低于基体的强度造成的;而塑性的下降则是由热浸镀时在基体表面形成的微裂纹造成的;由于残余应力的存在,微裂纹首先在σ-FeZn10层中形成,在受到拉应力时,裂纹沿晶界在σ-FeZn10层中向上扩展,然后在ζ-FeZn13层中裂纹沿着FeZn13/Zn的相界面扩展,最后在η-Zn层沿晶界扩展直至镀层发生完全断裂。 相似文献
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热浸镀铝低碳钢的力学性能和耐腐蚀性能研究 总被引:6,自引:1,他引:5
研究了热浸铝低碳钢的室温力学性能和耐腐蚀性能。结果表明,热轧低碳钢板热浸镀铝后的室温抗拉强度和延伸率均优于未镀铝的低碳钢板。拉伸断口的SEM观察表明,热浸镀铝低碳钢的拉伸断口是由钢基体的韧窝断口和Fe-Al合金层的穿晶解理断口组成。48h的中性盐雾试验结果显示热浸镀铝低碳钢管的耐蚀性远优于镀锌钢管。 相似文献
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采用机械镀Zn—RE作为Q235钢垫片的表面处理工艺,可使其镀层外观较机械镀锌显得更加细滑光亮,致密度和显微硬度增加,耐腐蚀性能大大提高,可更好地满足产品的性能要求。此外可提高锌粉的利用率,降低生产成本。 相似文献
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介绍了一种在Q235钢表面,利用等离子反应溅射直接复合渗镀合成氮化钛的工艺方法。该渗镀层是由钢铁材料基体上均匀分布细小氮化钛颗粒的渗层和表面氮化钛沉积层组成。沉积层与渗层之间有一平缓过渡区。渗层与基体是冶金结合,不会产生剥落。渗镀层表面硬度平均达到HV2300。X射线衍射结果表明,表面为纯氮化钛层,(200)晶面的衍射峰最强,具有明显的择优取向。用划痕仪进行结合强度检测,声发射曲线未见突起的信号峰值,表明结合强度好。复合渗镀氮化钛试样在10%硫酸、5%盐酸、3.5%氯化钠水溶液和硫化氢富液中进行腐蚀试验。耐腐蚀性能分别比改性前提高了789,26,3.3,67倍。 相似文献
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巴基管粒度对其复合镀层摩擦学性能影响的研究 总被引:4,自引:0,他引:4
用无电解复合镀方法,在45号钢基体上镀了一层镍-磷-巴基管复合镀层。本文详细实验研究了粒度对镍-磷-巴基管复合镀层摩擦学性能的影响。结果表明:巴基管复合镀层具有极优的摩擦学性能,而且巴基管的粒径愈小,复合镀层的摩擦学性能则愈优。 相似文献
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针对铝合金表面化学镀镍层结合力和耐蚀性差的问题,采用热处理方法提高镀层结合力和耐蚀性.高低温试验后用划痕法检测结合力强度,运用盐雾试验检测耐蚀性.通过对比试验和结果分析表明:热处理温度和时间对镀层性能存在交互作用;经过150℃、1.5h热处理,镀层与基体结合力最好,80h高、低温试验(高温105℃,低温-55℃)后,镀层结合力强度为48.7MPa;镀层经过150℃、1h热处理,镀层耐蚀性最好,96h盐雾试验后,外观无白斑、起泡、脱皮等腐蚀现象. 相似文献
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锌镍合金镀层基本无氢脆,又具有优异的耐蚀性,因而成为钢铁紧固件合适的防护层。通过电镀锌镍合金工艺试验,着重对锌镍合金镀层的外观及厚度、镍含量、结合强度、耐蚀性、油漆匹配性进行了分析研究。结果表明:电镀锌镍合金是一种适合钢铁紧固件的可靠的、综合性价比较高的防护层。 相似文献
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Wu Zhisheng Liu Cuirong Wang Jiuhai School of Materials Science Taiyuan University of Science Technology Taiyuan China Shan Ping Hu Shengsun Lian Jinrui School of Materials Science Tianjin University Tianjin China 《机械工程学报(英文版)》2005,18(1):17-20
The microstructure and elements distribution of the deep cryogenic treatment electrodes and non-cryogenic treatment electrodes for spot welding hot dip galvanized steel are observed by a scanning electrical microscope. The grain sizes, the resistivity and the hardness of the electrodes before and after deep cryogenic treatment are measured by X-ray diffraction, the DC double arms bridge and the Brinell hardness testing unit respectively. The spot welding process performance of hot dip galvanized steel plate is tested and the relationship between microstructure and physical properties of deep cryogenic treatment electrodes is analyzed. The experimental results show that deep cryogenic treatment makes Cr, Zr in deep cryogenic treatment electrodes emanate dispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non-cryogenic treatment ones so that the electrical conductivity and the thermal conductivity of deep cryogenic treatment electrodes are improved very much, which make spot 相似文献
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镀锌高强钢因具有高强度、耐腐蚀以及延展性优良等特点被应用于汽车构件领域,在实现减重的同时,提高汽车安全性能。电阻点焊作为材料连接的重要技术之一,因具有焊接过程简单、热影响区小、焊接变形与应力小及焊接速度快等优点,被广泛应用于连接镀锌高强汽车用钢。但在焊接过程中锌镀层会在电阻热的作用下熔化并渗入至焊点内部,从而在焊接接头形成液态金属脆化裂纹(Liquid metal embrittlement cracks, LME),液态金属脆化裂纹会使焊接接头在拉伸过程中发生脆性断裂,严重恶化焊接接头的力学性能。从液态金属脆化裂纹形成机理、表征手段和母材显微组织的影响等方面详细总结了国内外在此方面的研究,并归纳出改善镀锌高强钢焊接接头液态金属脆化裂纹的措施,为后续的研究工作提供一定的参考与借鉴。 相似文献
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空气助燃超音速火焰喷涂WC涂层的性能及应用 总被引:1,自引:0,他引:1
采用空气助燃超音速火焰喷涂(HVAF)技术制备了WC涂层,对该涂层的耐磨性、耐腐蚀性、韧性、涂层结合强度等性能进行了研究,并与电镀硬铬层进行了性能与实际使用寿命对比。结果表明:采用HVAF制备的WC涂层的耐磨性是电镀硬铬层的10倍,涂层的耐腐蚀性和韧性明显优于电镀硬铬层的;以WC涂层在瓦楞辊中的应用为例,采用上中下位置喷涂方法制备的WC涂层厚度均匀,控制喷涂角度大于60°和基体硬度小于60 HRC对WC涂层的结合强度有利,WC涂层瓦楞辊的使用寿命是电镀硬铬瓦楞辊的4~6倍。 相似文献
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Rosa Piotrkowski Enrique Castro Antolino Gallego 《Mechanical Systems and Signal Processing》2009,23(2):432-445
Acoustic emission (AE) signals obtained from scratch tests on hot dip galvanized samples with different corrosion levels were processed by wavelet transform (WT) analysis. Wavelet power was distributed in different frequency bands, according to damage mechanisms. The frequency bands were automatically obtained by searching for the relative minima of the wavelet entropy of signals and appropriate clustering methods. Correlation between the different mechanisms was corroborated by bispectrum analysis (BA). The damage evaluation entailed studying the evolution of the wavelet power in a specific frequency band, which corresponded to the fracture of the zeta phase columns of the galvanized coating. Results showed damage to increase along with the level of corrosion, but adherence was not dramatically affected in the studied corrosion range. The application of two signal-processing techniques, WT and BA, contributed to the consistency of our results. Besides the addressed technological application, we could demonstrate that that signal-processing techniques, when applied carefully, and results classified with care, are able to contribute to what is certainly an important problem, specially in cases like the treated here, where a complete physical theory relating damage and AE is not yet available. 相似文献