This paper systematically summarizes the development history and current situation of China’s titanium industry from the aspects of titanium resource distribution, production and processing, application fields, and distribution pattern of related enterprises. The paper analyzes the current problems of overcapacity and imbalance between supply and demand, the urgent need to optimize industrial structure, the insufficient linkage between upper design and lower industry, the urgent need for technological innovation and industrial upgrading, the dual challenges of resource and environmental constraints, and the dilemma of intensifying competition in domestic and foreign markets. The suggestions and prospects of optimizing cost structure and expanding application field, establishing a new collaborative mechanism of high-quality utilization of titanium materials and a cross-regional innovation platform of high energy level, guaranteeing incentive system to strengthen cooperation mechanism and play the role of strategic hinterland are put forward for the development of titanium and titanium alloy industry in Sichuan and Chongqing region.
Since the contacting ultrasonic detection results indicated some defects existed in a bar of Ti-6Al-4V alloy, researching work had been carried out using optical microscope, scanning electron microscope metallographic analysis, microhardness, energy spectrum, electron probe, backscatter electron diffraction and other characterization methods. And uncommon carbon enriched defect had been figured out. Flecks surrounded with α stable area were observed in the microstructure. Then, it was figured out that flecks were Ti2C with ordered FCC crystal and the α stable area was hard α phase based on the chemical composition and crystallology analysis. According to the distribution characteristics of chemical elements, the defect source was presumed to be raw materials contaminated by elements rich in carbon and nitrogen. Micro cracks initiated at Ti2C/α boundaries and grew into the α side in the hard α and Ti2C regions during the forging. Micro cracks would break through the Ti2C crystal bridges and merged into ultrasonically detectable macro crack defects at last.
High-titanium blast furnace slag, as an ordinary industrial solid waste, is characterized by low activity and low utilization rate due to its high TiO2 content and predominantly crystalline and stable mineral components, resulting in its accumulation. To better address the issues of low activity and utilization of high-titanium blast furnace slag, this review commences with an analysis of its powder properties and elaborates on four activation methods: mechanical activation, chemical activation, composite activation, and combined activation with other admixtures. The activation mechanisms of these four methods are also analyzed. Furthermore, the current research status and mechanisms of the influence of high-titanium blast furnace slag powder as an auxiliary admixture on the workability, mechanical properties, and durability of concrete are discussed. The environmental performance and economic benefits of high-titanium blast furnace slag powder are evaluated, and the shortcomings and future directions for enhancing its activity are pointed out. This study provides a reference for achieving better resource utilization of high-titanium blast furnace slag.
In the process of continuous casting, the distortion of molten steel flow in mold caused by nozzle clogging is a key factor affecting the quality and production efficiency of castings. To solve this problem, a multi area controllable electromagnetic braking (MAC-EMBr) technology is proposed to improve flow state of molten steel and reduce negative impact of nozzle clogging. Firstly, a slab mold is selected as the research object to establish an analytical model of molten steel flow and steel-slag interface behavior in electromagnetic continuous casting mold. Secondly, the fluid-flow-related phenomena of three casting cases in the slab mold, i.e., No-EMBr, Ruler-EMBr, and MAC-EMBr, are further investigated numerically to evaluate the metallurgical capability of the MAC-EMBr, including the non-uniform flow characteristics of molten steel and the evolution pattern of steel-slag interface inside the mold. According to the simulation results, with a 25% blockage rate of a single-side nozzle, the braking effect of the Ruler-EMBr on the backflow in the upper region of the mold is not remarkably. In detail, when the magnetic flux density reaches 0.3 T, the maximum magnitude of the surface velocity and the maximum amplitude of the level fluctuation on non-clogging side with the Ruler-EMBr are 16.7% and 1.6% higher than those with No-EMBr, respectively. This is not conducive to the stability of steel-slag interface in the mold. However, under the same magnetic flux density as the Ruler-EMBr, the application of MAC-EMBr has great potential to suppress the upward backflow on the non-clogging side. In comparison with No-EMBr, the maximum magnitude of the surface velocity and the maximum amplitude of the level fluctuation with the MAC-EMBr are decreased by 16.7% and 48.4%, respectively. As a result, the flow of molten steel in the mold can be well controlled in different regions with the MAC-EMBr, so as to improve the symmetry of the flow field and reduce the flow asymmetry caused by nozzle clogging.
总结回顾了中国钛白粉工业2019、2020年的各项行业数据和表现,分析了当前面临的形势及发展趋势,认为高质量发展成为钛白粉行业未来发展的主旋律,钛白粉产能集中度虽有提高,但洗牌效应短期内难以呈现,这也是行业发展的一个难题,另外行业监管、氯化法钛原料问题、环保及清洁生产问题仍不容忽视。
从2020年我国钛工业钛精矿、海绵钛、钛锭、钛材等品种的产能、产量、应用和进出口等数据分析了我国钛工业的整体情况,并对目前行业存在的问题提出了建议。
简述了连铸板坯电磁搅拌技术的发展过程和现存问题,重点阐述了连铸板坯生产过程中结晶器内和二冷区电磁搅拌的工作原理和技术特点,对电磁搅拌器的安装位置进行了归纳,同时总结了板坯结晶器电磁搅拌和二冷区电磁搅拌的研究现状,探究了影响板坯电磁搅拌效果的因素及其主次关系,归纳了用于二冷区电磁搅拌支撑辊的作用及需继续探究的方向,分析了板坯电磁搅拌技术对铸坯内元素分布和等轴晶区间隙率的影响,为以后的板坯电磁搅拌研究者提供参考。
主要介绍先进热成形技术、脉冲电流辅助成形技术和电磁辅助成形技术的特点,及其在钛合金薄壁板材成形中应用的研究进展。热成形是钛合金塑性加工应用最为普遍的成形工艺,利用高温下钛合金塑性变形软化的特征,能够实现复杂钛合金零件的成形。脉冲电流和电磁辅助成形技术目前尚未开展大规模的产业应用,其在高强度难成形材料的成形加工方面具有潜在应用前景。
从2020年全球钒资源概况,五氧化二钒、偏钒酸铵、钒铁和钒氮合金等品种的产能、产量、需求、进出口贸易和市场价格等方面阐述和分析了钒工业的整体情况,并介绍了2020年全球钒电池领域发生的主要大事件。依据目前国内外钒行业运行态势对后市进行了展望,认为全球钒扩能态势短期内不会大改,钒产品供过于求的状态将促使价格呈现盘整回归态势。“双碳”背景下的中国市场依旧是全球钒需求的主场,钒氮合金亦将成为钒产品近中期的发展趋势,钒企间的协同创新将促进钒产业逐步呈现良性“竞合”局面。
在弹簧钢55SiCr成分基础上进行钒微合金化处理,获得了55SiCrV,通过淬火+回火正交试验、显微组织观察、力学性能测试和X射线衍射等手段,研究并分析了淬火+回火工艺对弹簧钢55SiCrV微观组织和力学性能的影响,结果表明:0.20%V的添加可使55SiCrV组织中存在大量弥散均匀分布的10~35 nm含钒析出相,强化效果最佳。淬火+回火处理可以改变55SiCrV的显微组织比例,其中的残余奥氏体可以降低强度和增加塑性,55SiCrV获得最佳力学性能匹配(Rm=1 815 MPa、Z=28%)的热处理工艺为900 ℃淬火+430 ℃回火,对应其残余奥氏体含量为2.3%。
β相凝固TiAl合金作为第三代TiAl基金属间化合物,凭借其突出的热变形优势,在航空航天及汽车制造等高端领域具有广阔的应用空间。然而,高温β相的引入在提高合金热变形能力的同时也使得组织演变和性能优化更为复杂。同时,受合金体系及本征脆性的影响,工业化进程相对迟缓。通过综述典型β相凝固TiAl合金的制备及加工工艺、组织与性能研究进展及工业化现状,系统分析了合金制备及加工工艺和成本优势,阐明了合金体系热变形、热处理及合金化对组织演变和性能优化的作用机制,指出合金工业化发展的限制环节及未来发展趋势。
采用金相显微镜、XRD射线衍射仪及维氏硬度计等,研究了普通热处理和深冷处理工艺对Cr12MoV钢显微组织及硬度的影响。结果表明:Cr12MoV钢经普通热处理和深冷处理淬火后的组织均为隐针马氏体+残余奥氏体+碳化物,200 ℃低温回火后组织转变为回火马氏体+碳化物+残余奥氏体。深冷处理可大幅减少钢中残余奥氏体,提升钢的硬度;热处理采用1020 ℃加热保温60 min淬火+(−196 ℃)深冷2 h+200 ℃回火保温120 min,硬度(HV30)值最高,可达780。
总结梳理了2022年中国钛白粉行业的各项运行数据,如产能、产量、市场表观需求量、产能分布等,重点分析了近期钛白粉产能增长趋势及相应钛矿原料供求关系的变化。指出,2022年钛白粉产量、产能继续保持增长趋势,产能集中度进一步提高;同时,现有生产商规模的进一步扩大,业外加盟项目的增加,将导致钛矿供应的紧缺。另外,随着绿色新能源电池材料产业的兴起,大批磷酸铁或磷酸铁锂项目建设或筹建,将导致钛白粉产能激增,加剧钛矿供需矛盾,届时市场前景和行业面貌堪忧,各方应高度关注和及时调整。
从2022年我国钛工业钛精矿、海绵钛、钛锭、钛材等品种的产能、产量、应用和进出口等数据分析了我国钛工业的整体情况,并针对目前行业存在的问题提出了建议。