【摘 要】
：
The influence of cooling rate on microstructural evolution and precipitation behavior in Ti,Ti-Nb and Ti-Mo low-carbon steels during the continuous cooling process was studied by dilatometer method,optical microscopy,and transmission electron microscopy.T
【机 构】
：
State Key Laboratory of Solidification Processing,Center of Advanced Lubrication and Seal Materials,
论文部分内容阅读
The influence of cooling rate on microstructural evolution and precipitation behavior in Ti,Ti-Nb and Ti-Mo low-carbon steels during the continuous cooling process was studied by dilatometer method,optical microscopy,and transmission electron microscopy.The results indicated that austenite transformation temperature decreased with the increasing cooling rate in three steels.The addition of Nb and Mo promoted bainite and martensite transformation and improved the hardenability of steels.In addition,precipitates formed in deformed austenite and ferrite can be observed simultaneously.Deformation in the austenite non-recrystallization zone can introduce a large number of deformation bands,and then,the precipitates preferentially nucleated in these deformation bands.In the following process,randomly distributed precipitates and interphase precipitates will be formed in ferrite.The precipitates formed in deformed austenite obey Kurdjumov-Sachs orientation relationship with the matrix,while the precipitates formed in ferrite obey Baker-Nutting orientation rela-tionship with the matrix.The addition of Nb and Mo in Ti-bearing steels decreased the precipitates size and increased the number density of precipitates and then improved the precipitation hardening.And the effect of Mo addition is more obvious than that of Nb addition.
其他文献
随着人工智能(Artificial Intelligence,AI)在自动驾驶和可穿戴等复杂环境中得到广泛应用,一种高效率的语义分割模型成为神经网络模型重要的解决对象.以传统ENET网络模型为基础,提出改进ENET网络,可利用深度学习处理单元(DPU)内部的EeLU激活函数硬件模式减少参数以改进ENET网络,提高DPU的工作性能.通过搭建语义分割的Vitis-AI架构平台,完成构建量化模型和模型网络的训练学习.对比分析多种语义分割试验结果,改进ENET网络,使用更少计算资源达到最优精度,在ZCU106的硬
以碳酸二乙酯(DEC)、1,6-己二胺(HDA)为原料、无水醋酸锰为催化剂,合成了 1,6-六亚甲基二氨基甲酸乙酯(HDEC).通过红外光谱、核磁共振氢谱、气相色谱确定HDEC标样的结构和纯度,并建立了定量分析方法.进一步采用气质联用对反应的主副产物进行定性分析,推测反应路径.同时,对合成工艺进行反应参数优化,并推测反应机理.结果表明,该反应通过两步实现,首先HDA与DEC反应生成单取代的1-(6-氨基)-六亚甲基单氨基甲酸乙酯(HMEC)中间体,HMEC进一步与DEC羰化反应生成HDEC目标产物,同时反
预制T形梁技术因其施工质量高、建造速度快、工程造价低等特点,在桥梁工程中具有广泛的应用.为了分析T形梁抗弯剪力学性能,通过对T形梁足尺模型构件进行弯剪耦合性能试验,研究预应力钢绞线折线张拉时的T形梁的应力分布,探究各级工况荷载条件下T形梁的抗裂性能和极限承载性能.结果表明:在弯剪耦合作用下,梁初始开裂出现在加载区域,加载截面总剪力略小于支点截面总剪力;梁底混凝土最大正应变增量截面在构件自重和0.85倍预应力荷载共同作用下的正应力小于0,且截面最大主拉应力小于C60混凝土主拉应力限值,符合抗裂性要求;东、西
The influences of Al2O3/Na2O ratio and MnO content on high-temperature properties,such as melting,crystallization,heat transfer,and viscosity of mold flux for casting peritectic steel,have been investigated.The results show that the melting temperatures o
Controlling the flow behavior in the mold in an appropriate way is the basis for realizing the billet ultra-high speed continuous casting.Based on the new proposed physical water modeling experiment considering the effects of solidified shell and hydrosta
Direct strip casting(DSC)is one of the cutting-edge technologies for the steel industry in the twenty-first century.Under the background of carbon peak and carbon neutrality,DSC technology has a bright future of applications as it requires less production
During the conventional continuous casting process of high-aluminum steels(w([Al])＞0.5 wt.％),some components of slag,such as SiO2,B2O3,and TiO2,could be reduced by aluminum in molten steel.Therefore,the CaO-BaO-Al2O3-CaF2-Li2O non-reactive mold fluxes wer
In steel continuous casting(CC),the choice of the appropriate speed at which the slab is cast can be influenced by many different factors and phenomena.While the slab thickness seems to have the biggest impact,other features like the slab width have been
Based on the principle of speed superposition,the oscillation system for continuous casting mold synchronously driven by double servomotors can adjust all parameters online with high reliability and high bearing capacity.The elastodynamic model of the osc
针对火星探测器进入飞行弹道的高马赫数、化学非平衡效应和低动压等特点,提出了一种基于火星进入大气数据系统/惯性测量单元(MEADS/IMU)耦合的测量方法,实现海拔60 km以下区域的火星大气数据测量.利用自主研发CACFD软件平台的化学非平衡模型/完全气体模型计算获得探测器宽速域飞行流场的表面压力点数据,建立了基于BP神经网络的MEADS算法模型.在高马赫数段(Ma＞12)利用IMU测量获得的马赫数作为输入条件,结合MEADS算法测量获得总压、动压、静压、攻角和侧滑角等飞行大气参数,成功克服了马赫数无关性