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本文利用透射电子显微镜研究了钛合金的界面相。电子衍射花样表明,靠近β相的界面相为面心立方结构,靠近α相一侧为六方结构。在界面处及基体α相之间观察到大量的高密度位错,位错形成的亚晶与基体α相存在(101)的孪晶关系;(001)α与(110)β近似平行,并不互相平行,它们之间夹角为1.5º。当样品较厚时,这种临近的衍射斑点就会出现二次衍射,产生莫尔条纹。 相似文献
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文章介绍了3种不同的传感器在材料动态力学测试中的应用,详细论述了其各自不同的测试原理与配套设备。 相似文献
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中厚板拉伸试样出现了延伸率不合问题,并且拉伸试样断口出现了层状撕裂现象。通过对试样断口形貌、试样变形区和未变形区金相组织的研究,认为:中厚板中心区域珠光体比例高是层状撕裂试样厚度中心呈现脆性的原因,这种脆性区导致在拉伸过程中最先萌生裂纹,并最终导致拉伸试样延伸率不合;出现层状撕裂的试样在拉伸之前并不存在结构上的分层和断口分层,在断口上出现的平行于轧制方向的裂纹是在拉伸过程中形成的;当珠光体带的宽度超过25 μm时,试样在拉伸过程中在珠光体带中易出现裂纹并导致断口出现层状撕裂。 相似文献
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本文综述了材料的使用状态对于材料的磁、声、电等多方面物理性能影响,从而确定了通过测定材料的物理性能参数来判别其使用状态的可行性。同时发现铁磁材料的磁导率、矫顽力与剩余磁感应强度等磁性能参数对于材料的非损伤变化,如位错密度的改变也很敏感,因此对于无明显损伤或严重缺陷,但在上一个使用周期中确实使用了相当一段时间的再制造机械产品,可以通过检测材料的这些磁性能参数将它们检验鉴别出来,这也为更好地判定再制造机械产品的剩余寿命提供了科学的依据。
关键词:物理性能,使用状态,再制造 相似文献
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It is an important challenge to reduce the carbon content in nanostructured bainitic steels for commercialization purposes while still being able to gain the desired microstructural characteristics in nanoscale and not to deteriorate the strength-ductility combinations. That is the point at which an appropriate heat treatment procedure design would be an important parameter. This article aims to investigate how to obtain nanostructured bainite in steel with 0.26 wt% carbon content by applying multi-step austempering procedures. One-, two- and three-step austempering processes have been implemented, and proper heat treatment temperatures and approaches were selected based on dilatometry tests. Results indicated that it has become possible to achieve bainitic ferrites and austenite films with overall thicknesses of 164, 145 and 132 nm and 134, 105 and 90 nm at the end of one-, two- and three-step austempering heat treatments, respectively. Meanwhile, microstructural characteristics resulted in enhanced mechanical properties with ultimate tensile strength (UTS) of 1435, 1455 and 1428 MPa in combination with elongation levels of 15.4, 13.6 and 11.4% after implementing those heat treatments. Finally, it has been shown that applying the multi-step austempering heat treatments resulted in enhanced yield strength and impact toughness values due to the microstructural characteristics and proper heat treatment procedure design. 相似文献
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奥氏体变形条件下低碳微合金钢中的贝氏体相变 总被引:4,自引:2,他引:2
采用Gleeble-1500热模拟机对低碳Mn-Nh-Ti钢进行了奥氏体区变形和变形后的冷却试验,借助于光学显微镜和扫描电镜分析了变形和冷却速度对显微组织的影响。结果表明,随着奥氏体形变量的增大,奥氏体向铁素体的相变增加,向贝氏体的相变减少,贝氏体中的铁素体和小岛由细长条状逐渐向近等轴状变化,铁素体板条间的小岛逐渐变化为存在于某些铁素体的晶界上。随着变形后的奥氏体冷却速度增大,铁素体量减少,贝氏体量增加,粒状贝氏体也逐渐由板条贝氏体所取代。 相似文献
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Hou Xiaoying Xu Yunbo Wu Di State Key Laboratory of Rolling Automation Northeastern University Shenyang China 《稀有金属材料与工程》2011,(Z3)
The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental results showed that in the multiphase microstructure of the investigated steel when the finish rolling temperature was about 820 ℃ and the final air cooling temperature was in the range of 630-700 ℃, the grain size of most of ferrite was finer (about 4 μm) and which had higher dislocation density, t... 相似文献
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采用铸坯锻热等温淬火工艺生产的高碳低合金钢贝氏体磨球,其硬度与韧性配合良好,与铸造工艺比较,生产工艺简单,成本低、质量好,经生产和装机运行表明,具有良好的应用和发展前景。 相似文献
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低碳微合金钢贝氏体相变及组织细化的研究 总被引:2,自引:2,他引:0
针对低碳铌、钛微合金钢,采用Gleeble-1500热模拟机进行了加热、变形及冷却试验,对不同工艺制度下的显微组织进行了分析.结果表明,加热时间较长时,不利于随后冷却奥氏体向等轴铁素体相变,而发生贝氏体相变;在奥氏体区进行不同应变量的变形,随着奥氏体的形变量加大,相变贝氏体的组织细化;变形后适当增加弛豫时间,相变的贝氏体组织细化. 相似文献
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