共查询到17条相似文献,搜索用时 109 毫秒
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目的研究加热温度、加热时间等工艺参数对Al-Si镀层材料在热成形过程中存在的表面颜色差异、镀层厚度和扩散层厚度的影响规律,及影响零件表面颜色差异的主要原因。方法在不同加热时间及加热温度条件下,对厚度为1.0 mm的新日铁Al-Si镀层材料进行热冲压试验,测量热成形零件的镀层厚度和扩散层厚度,并对典型不同颜色零件表面进行SEM及EDS分析研究。结果 Al-Si镀层热成形零件表面颜色与加热温度和加热时间存在较好的对应关系,同时镀层厚度及扩散层厚度随着加热时间的增加及加热温度的提高而增大,Al-Si镀层热成形零件表面的颜色与镀层中不同铁氧化物的混合比例存在较好的对应一致性。结论Al-Si镀层热成形零件表面颜色的状态可以间接反应镀层厚度及扩散层厚度。 相似文献
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目的 对QP1180和22MnB5激光拼焊板进行热成形试验,以解决超高强钢板材焊后的软化问题。方法 选择QP1180和22MnB5异种高强钢作为母材进行激光自熔焊,对焊后的激光拼焊板进行热成形试验,通过体式显微镜、扫描电子显微镜、液压拉伸试验机和维氏硬度计等手段,分析热成形前后激光拼焊板微观组织和力学性能的变化。结果 与焊态拉伸试样相比,热成形试样抗拉强度提高了135%,断后伸长率降低了55%,拉伸试样都在22MnB5母材处断裂,均为塑性断裂。在热成形后,对焊接接头进行组织分析,发现QP1180母材区马氏体含量增加,22MnB5母材区和临界热影响区组织由珠光体和铁素体转变为马氏体,焊接接头热影响区各亚区的组织均转变为大小不同的板条马氏体。硬度测试结果表明,焊态试样焊接接头的QP1180临界区存在软化现象,硬度值最低为335HV,22MnB5侧硬度值由母材处向焊缝升高,母材硬度最低为170HV;而在热成形后,QP1180临界区软化现象消失,硬度值趋于平缓,22MnB5母材处硬度比焊态试样硬度高了2倍。结论 与焊态试样相比,经热成形后激光拼焊板的焊后软化问题得到了解决。 相似文献
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门内板是激光拼焊板应用于汽车车身的主要零件之一,通常由差厚板激光拼焊后经冲压成型。由于存在焊缝,且焊缝两侧的板料性能、厚度存在差异,在靠近焊缝的薄板侧很容易发生开裂,即随着板厚比例增大,破裂危险也相应增加,反之亦然。重要的是,门内板开裂问题会严重影响汽车质量,所以我们必须深入分析并解决问题。 相似文献
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系统阐述了汽车车身轻量化设计过程中运用的3种主要方法:在车身结构优化设计方面,详细介绍了拓扑优化、灵敏度分析和形貌及尺寸优化在车身轻量化设计中应用的步骤及方法;在先进工艺应用方面,介绍了激光拼焊板、热冲压成形技术、辊压成形技术的优缺点,以及这些先进工艺应用于车身的位置;在车身新材料应用方面,介绍了高强度钢板、铝合金、塑料及高分子复合材料、静音钢板和结构发泡材料等在车身上的应用及发展情况.以大量实例和统计数据,并通过表征车身轻量化的关键指标——车身轻量化系数验证,得出汽车车身轻量化设计的步骤及发展方向. 相似文献
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为了促进Zn-Al-Si镀层的开发应用,介绍了攀钢Zn-15 %Al-Si镀层的开发情况,探讨了改良森吉米尔法工艺生产Zn-15 %Al-Si镀层时清洗、带钢入锌锅温度、镀液温度、气刀和镀后冷却等环节的工艺控制,通过合理的工艺控制,得到了表面质量良好、锌花均匀的镀层,对于提高钢板耐腐蚀性能和降低锌的使用具有重要意义. 相似文献
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Tailor welded blanks (TWBs) are blanks that are tailor made to suit the required function. They are made by joining blanks of different thicknesses, materials, coatings, etc. The forming behaviour of such TWBs will be different from the conventional blanks, as TWBs with different strength levels will be subjected to the same forming loads but will result in unequal deformation values. The present work is aimed at studying the formability behaviour of TWBs of two different materials namely AA6061 and AA2014. The blanks were made by friction stir welding process at different rotational speeds, welding speeds and tool tilt angles on a vertical head milling machine. The formability of the TWBs and the base materials has been studied before and after solution heat treatment and analysed with the help of Limiting Dome Height (LDH) test. A differential heat treatment approach has been followed, which is unique in this work. From the results, it was found that the formability of heat treated TWBs were higher than those of base materials and untreated TWBs. 相似文献
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The hot stamping potential of three commercial carbon–manganese–chromium steels was demonstrated. The steels were selected with the intention of producing ultrahigh strength ferritic–martensitic dual phase microstructures from hot stamping heat treatment, exhibiting superior tensile properties for ‘impact energy absorptive’ crash performance compared to the conventional carbon–manganese–boron steel for automotive hot stamping technologies, 22MnB5. Compared to 22MnB5, each of the carbon–manganese–chromium steels provided at least twice the total elongation, yet with a relatively small loss to ultimate tensile strength. It was concluded that the carbon–manganese–chromium steels provide superior tensile properties for impact energy absorptive crash performance, while exhibiting ‘lean’ chemical compositions compared to previously investigated steels with similar aims and offer opportunities for use in the ‘tailor welded blank’ concept. 相似文献
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Reducing the forming load,deletion of springback,increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process.Hot stamping process and 22MnB5 steels are the state of the art process and grades,respectively;however novel processes and steel grades are under considerations.In the current research,behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized.During semi-hot stamping process,the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly,simultaneously.Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks.The hot stamped blanks attained the strength values as high as water quenched blanks.The highest ductility and consequently,the best formability were achieved for the blank which had been semi-hot stamped.It was concluded that for the mentioned steel,semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability,but also led to ultra high strength values. 相似文献
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A multi-step analysis for determining admissible blank-holder forces in deep-drawing operations 总被引:1,自引:0,他引:1
In present investigation a methodology to determine admissible blank-holder forces in deep-drawing operations was established. According to this methodology, the deep-drawing operation is simulated and the maximum blank-holder forces, for stamping friction stir welded tailored blanks, are established based on the comparison of the numerical principal strains fields, obtained in the numerical simulations, with the limiting strains determined analytically for both base materials. Supporting experiments were performed and its results used to confirm the quality of the numerical predictions. 相似文献
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