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采用非平衡磁控溅射离子镀技术,通过调节Cr靶的溅射功率。在单晶硅基片上沉积制备了一系列不同Cr含量的类石墨(Cr—GLC)镀层样品。利用Raman光谱仪、X射线光电子能谱(XPS)、透射电子电镜(TEM)、显微硬度计分析了Cr—GLC的微观结构和显微硬度。结果表明,利用非平衡磁控溅射得到的Cr—GLC镀层,随Cr含量的增高,硬度逐渐降低并趋于稳定。当Cr含量小于4%时,Cr只以单质非晶态分布于非晶GLC中,Cr的掺杂降低了内应力;当Cr含量超过49/6后,还有CrC。纳米晶存在于非晶态的GLC中;镀层由C、Cr和CrC。纳米晶粒组成非晶纯构, 相似文献
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本文以莱钢4300mm宽厚板生产线MULPIC冷却系统生产Q890D高强钢为研究对象,通过对DQ冷却策略、水处理系统、生产组织及水比参数等进行优化,成功开发出800MPa级高强高韧钢。检验结果表明,采用在线淬火+离线回火工艺生产Q890D钢板,其组织为回火马氏体和回火索氏体,钢板力学性能优良,组织、性能均匀性好。 相似文献
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通过热模拟试验研究了铝硅合金化耐候钢在形变强化相变及冷却过程中的组织演变规律。结果表明.其组织演变符合低碳钢形变强化相变的基本规律,形变温度较低时,铁素体转变量较高,晶粒尺寸较小。奥氏体晶粒细化促进形变强化相变过程的发生。经高温奥氏体和形变强化相变两道次变形并控制后续冷却工艺可以获得细晶铁素体和不同第二组织——直接淬火为铁素体(F)+马氏体(M),以30℃/s冷却为铁素体(F)+贝氏体(B),以2℃/s冷却为铁素体(F)+珠光体(P)。当冷却速度大于30℃/s时,细晶铁素体长大不明显。 相似文献
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The evolution of the grain structures in AA2195 Al-Li alloy plate warm-rolled by 80% reduction during recrystallization annealing at 500℃ was investigated by electron backscatter diffraction, scanning electron microscopy and transmission electron microscopy. It is found that the elongated grain structures are caused by the lamellar distribution of recrystaUization nucleation sites, being lack of large second phase particles (〉 1μm), and dispersive coherent particles (such as δ′ and β′concentrated in planar bands. The recrystallization process may be separated into three stages: firstly, recrystallization nucleation occurs heterogeneously, and the nuclei are concentrated in some planar zones parallel to rolling plane. Secondly, the grain boundaries interacted with small particles concentrate in planar bands, which is able to result in the elongated grain structures. The rate of the grain growth is controlled by the dissolution of these small particles. Thirdly, after most of small particles are dissolved, their hindrance to migration of the grain boundaries fades away, and the unrecrystallized zones are consumed by adjacent recrystallized grains. The migration of high angle grain boundaries along normal direction leads a gradual transformation from the elongated grains to the nearly equiaxed, which is driven by the tension of the grain boundaries. 相似文献
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稀土对钢焊缝组织的影响 总被引:2,自引:1,他引:1
通过在碱性药皮中添加稀土的正交试验,研究了不同稀土剂对钢焊缝组织的影响。结果表明,稀土能够抑制晶界铁素体和侧板条铁素体,促进针状铁素体并细化晶粒。按照作用效果,稀土剂的顺序为:稀土硅、稀土镁、氟化铈和氟铈镧矿。稀土剂的最佳添加量约为药皮干粉重量的3%. 相似文献
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采用冲击试验仪器化试验方法和拉伸试验方法对汽轮机缸体用耐热钢不同状态(未经时效、经过593℃时效5600h)的动态断裂韧度及抗拉强度和塑性进行了研究,同时进行了SEM和物相分析。结果表明,在不同试验温度条件下,与未时效相比,经时效后材料的KId值和断口的侧膨胀值均有所降低;抗拉强度稍有增加,塑性略有降低。在时效试样的晶内与晶界处碳化物数量略有增加,主要是含铬的M23C6相有微量从基体中弥散析出;部分碳化物颗粒发生聚集和长大,试样中第二相平均粒径相对稍大。 相似文献