2024, 45(6): 1-6.
doi: 10.7513/j.issn.1004-7638.2024.06.001
Abstract:
Laser additive manufacturing technology on high-performance metallic components has shown great potential and broad application prospects in the manufacturing of key equipment. Beihang University has conducted deep research on laser additive manufactured large metallic components and achieved many research breakthroughs. In this article, the progress of laser additive manufactured high-performance metal structural materials was summarized. The non-equilibrium solidification and nucleation growth behavior were revealed, and the active control method on grain morphologies of titanium alloys and nickel-based superalloys was established. Besides, new strengthening and toughening mechanisms for laser additive manufactured materials were proposed, while titanium alloy and ultra-high strength steel specially for additive manufacturing were developed. Future research interests will continue to focus on fundamental issues such as laser/metal interaction behavior, material solidification and phase transition laws, as well as the design and development of high-performance new alloys based on extreme metallurgical conditions of laser additive manufacturing. Thus, the transformative potential of laser additive manufacturing technology in the manufacturing of large metal components for key equipments can be further unleashed.
Laser additive manufacturing technology on high-performance metallic components has shown great potential and broad application prospects in the manufacturing of key equipment. Beihang University has conducted deep research on laser additive manufactured large metallic components and achieved many research breakthroughs. In this article, the progress of laser additive manufactured high-performance metal structural materials was summarized. The non-equilibrium solidification and nucleation growth behavior were revealed, and the active control method on grain morphologies of titanium alloys and nickel-based superalloys was established. Besides, new strengthening and toughening mechanisms for laser additive manufactured materials were proposed, while titanium alloy and ultra-high strength steel specially for additive manufacturing were developed. Future research interests will continue to focus on fundamental issues such as laser/metal interaction behavior, material solidification and phase transition laws, as well as the design and development of high-performance new alloys based on extreme metallurgical conditions of laser additive manufacturing. Thus, the transformative potential of laser additive manufacturing technology in the manufacturing of large metal components for key equipments can be further unleashed.
2024, 45(6): 19-27.
doi: 10.7513/j.issn.1004-7638.2024.06.003
Abstract:
Using the iron-manganese-rich leaching solution generated during vanadium extraction from vanadium slag was used as the raw material, and ferromanganese oxalate dihydrate Mn0.5Fe0.5C2O4∙2H2O was prepared by co-precipitation, and lithium ferromanganese iron phosphate LiFe0.5Mn0.5PO4 anode material was successfully synthesized by the high-temperature solid-phase method using this precursor, which achieved the comprehensive utilization of the iron-manganese resources in the vanadium slag leaching solution. The results showed that under the conditions of initial pH 3.5, temperature 25 ℃, reaction time 90 min, ammonium oxalate addition 1.1 times of the theoretical value, and the addition mode of positive addition, the precipitation efficiency of Fe and Mn were 99.5% and 99.4%, respectively. The depth separation from other impurities was achieved, and the purity of Mn0.5Fe0.5C2O4·2H2O reached 99.97% with small particle sizes and good dispersion. It can be used as a precursor for synthesizing lithium manganese iron phosphate cathode materials, which provides the idea for the industrial production of lithium iron manganese phosphate.
Using the iron-manganese-rich leaching solution generated during vanadium extraction from vanadium slag was used as the raw material, and ferromanganese oxalate dihydrate Mn0.5Fe0.5C2O4∙2H2O was prepared by co-precipitation, and lithium ferromanganese iron phosphate LiFe0.5Mn0.5PO4 anode material was successfully synthesized by the high-temperature solid-phase method using this precursor, which achieved the comprehensive utilization of the iron-manganese resources in the vanadium slag leaching solution. The results showed that under the conditions of initial pH 3.5, temperature 25 ℃, reaction time 90 min, ammonium oxalate addition 1.1 times of the theoretical value, and the addition mode of positive addition, the precipitation efficiency of Fe and Mn were 99.5% and 99.4%, respectively. The depth separation from other impurities was achieved, and the purity of Mn0.5Fe0.5C2O4·2H2O reached 99.97% with small particle sizes and good dispersion. It can be used as a precursor for synthesizing lithium manganese iron phosphate cathode materials, which provides the idea for the industrial production of lithium iron manganese phosphate.
2024, 45(6): 64-73.
doi: 10.7513/j.issn.1004-7638.2024.06.009
Abstract:
The influence of α/β volume fraction and grain size on the tensile mechanical properties of Ti-6Al-4V dual-phase titanium alloy was investigated in this study using the crystal plasticity finite element method. The contribution of different slip systems to plastic deformation was evaluated quantitatively by slip relative fraction. The results demonstrate that the stress-strain distribution during the tensile deformation of Ti-6Al-4V titanium alloy is non-uniform. The stress is primarily concentrated on the β phase grain and grain boundary, while the strain is concentrated on the α phase grain. Increasing the volume fraction of β phase leads to a larger stress concentration area, easier generation of strain concentration at the triple-junction of grain boundaries, and a significant increase in contribution from the β phase{110} slip system to the plasticity deformation. Increasing α, β or two-phase grain size results in decreased stress-strain curve in the plastic region, where initial deformation is predominantly governed by prismatic slip system while pyramidal <c+a> slip system contribute slightly less. An increase in α-phase grain size leads to a decrease in the activity of pyramidal <c+a> slip system, resulting in reduced stress values in the plastic region. Increasing the β-phase grain size results in a reduction of stress during the plastic stage, which is attributed to the decreased activity of {110} slip system within the β-phase. Simultaneously increasing the grain size of both the α and β phases will affect the activation fraction of prismatic and {110} slip systems. The reduction in stress is associated with the significant decrease in the number of interfaces.
The influence of α/β volume fraction and grain size on the tensile mechanical properties of Ti-6Al-4V dual-phase titanium alloy was investigated in this study using the crystal plasticity finite element method. The contribution of different slip systems to plastic deformation was evaluated quantitatively by slip relative fraction. The results demonstrate that the stress-strain distribution during the tensile deformation of Ti-6Al-4V titanium alloy is non-uniform. The stress is primarily concentrated on the β phase grain and grain boundary, while the strain is concentrated on the α phase grain. Increasing the volume fraction of β phase leads to a larger stress concentration area, easier generation of strain concentration at the triple-junction of grain boundaries, and a significant increase in contribution from the β phase{110} slip system to the plasticity deformation. Increasing α, β or two-phase grain size results in decreased stress-strain curve in the plastic region, where initial deformation is predominantly governed by prismatic slip system while pyramidal <c+a> slip system contribute slightly less. An increase in α-phase grain size leads to a decrease in the activity of pyramidal <c+a> slip system, resulting in reduced stress values in the plastic region. Increasing the β-phase grain size results in a reduction of stress during the plastic stage, which is attributed to the decreased activity of {110} slip system within the β-phase. Simultaneously increasing the grain size of both the α and β phases will affect the activation fraction of prismatic and {110} slip systems. The reduction in stress is associated with the significant decrease in the number of interfaces.
2024, 45(6): 108-118.
doi: 10.7513/j.issn.1004-7638.2024.06.015
Abstract:
In this paper, based on the actual dimension of the vanadium titanomagnetite blast furnace of a domestic enterprise, a three-dimensional physical model is established. The numerical simulation method is used to compare and study the flow and combustion behavior of pulverized coal in the tuyere gyration area under different oxygen enrichment methods. The results show that the overall trend of the tuyere velocity change with the oxygen enrichment rates is consistent with that of the constant air enrichment mode, but the difference in the change amplitude is significant. That is, when the oxygen enrichment rate is increased by 1%, the cross-sectional velocity of the tuyere is increased by 4.25 m/s (fixed air) and 0.41 m/s (reduced air), respectively. Under the two oxygen enrichment modes, the temperature, reducing gas content and burnout rate of the pulverized coal in the gyratory area have the same trend with the oxygen enrichment rates. As temperature increases, the high temperature area expands with the increase in the reducing gas content, and the burnout rate of pulverized coal increases. Among them, the amount of N2 brought into the blast furnace decreases due to the decrease in hot air flow rate, and the content of CO and H2 in the coal gas changes greatly, preventing the formation of carbon nitrides and titanium carbides, and improving the reduction effect of iron ore in the blast furnace. It is calculated that the average temperature of the gyratory zone is increased by 34.22 K (fixed air) and 32.88 K (reduced air) for every 1% increase in the oxygen enrichment rate. Under the condition of reduced air and oxygen enrichment, the N2 content brought into the blast furnace is reduced by 10 m3/min and the CO concentration in the gas is increased by 8.61%.
In this paper, based on the actual dimension of the vanadium titanomagnetite blast furnace of a domestic enterprise, a three-dimensional physical model is established. The numerical simulation method is used to compare and study the flow and combustion behavior of pulverized coal in the tuyere gyration area under different oxygen enrichment methods. The results show that the overall trend of the tuyere velocity change with the oxygen enrichment rates is consistent with that of the constant air enrichment mode, but the difference in the change amplitude is significant. That is, when the oxygen enrichment rate is increased by 1%, the cross-sectional velocity of the tuyere is increased by 4.25 m/s (fixed air) and 0.41 m/s (reduced air), respectively. Under the two oxygen enrichment modes, the temperature, reducing gas content and burnout rate of the pulverized coal in the gyratory area have the same trend with the oxygen enrichment rates. As temperature increases, the high temperature area expands with the increase in the reducing gas content, and the burnout rate of pulverized coal increases. Among them, the amount of N2 brought into the blast furnace decreases due to the decrease in hot air flow rate, and the content of CO and H2 in the coal gas changes greatly, preventing the formation of carbon nitrides and titanium carbides, and improving the reduction effect of iron ore in the blast furnace. It is calculated that the average temperature of the gyratory zone is increased by 34.22 K (fixed air) and 32.88 K (reduced air) for every 1% increase in the oxygen enrichment rate. Under the condition of reduced air and oxygen enrichment, the N2 content brought into the blast furnace is reduced by 10 m3/min and the CO concentration in the gas is increased by 8.61%.
2021, 42(2): 1-4.
doi: 10.7513/j.issn.1004-7638.2021.02.001
摘要：
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。
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。
2021, 42(3): 1-9.
doi: 10.7513/j.issn.1004-7638.2021.03.001
摘要：
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。
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。
2021, 42(5): 149-157.
doi: 10.7513/j.issn.1004-7638.2021.05.023
摘要：
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。
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。
2021, 42(5): 1-9.
doi: 10.7513/j.issn.1004-7638.2021.05.001
摘要：
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。
2021, 42(6): 17-27.
doi: 10.7513/j.issn.1004-7638.2021.06.002
摘要：
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。
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。
2021, 42(3): 187-192.
doi: 10.7513/j.issn.1004-7638.2021.03.028
摘要：
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%。
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%。
2021, 42(6): 1-16.
doi: 10.7513/j.issn.1004-7638.2021.06.001
摘要：
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。
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。
2021, 42(3): 148-154.
doi: 10.7513/j.issn.1004-7638.2021.03.023
摘要：
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。
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。
2021, 42(2): 179-187, 192.
doi: 10.7513/j.issn.1004-7638.2021.02.029
摘要：
为了探究Mg处理对易切削钢中夹杂物的影响，以1144高硫易切削钢为试验钢种，采用金相和能谱仪等手段研究了Mg处理对1144易切削钢中夹杂物的形态、尺寸分布和夹杂物成分的影响。结果表明：在易切削钢铸坯中，Mg处理使得易切削钢铸坯硫化物夹杂由Ⅱ类向Ⅲ类、Ⅰ类转变，分布更为均匀，同时使得复合硫化锰夹杂物比例提升。在轧材中，使得钢中夹杂物球化，并且钢中硫化锰夹杂物的尺寸和分布也得到了较好的改善，同时，Mg处理能够有效提高易切削钢的切削加工性能。
为了探究Mg处理对易切削钢中夹杂物的影响，以1144高硫易切削钢为试验钢种，采用金相和能谱仪等手段研究了Mg处理对1144易切削钢中夹杂物的形态、尺寸分布和夹杂物成分的影响。结果表明：在易切削钢铸坯中，Mg处理使得易切削钢铸坯硫化物夹杂由Ⅱ类向Ⅲ类、Ⅰ类转变，分布更为均匀，同时使得复合硫化锰夹杂物比例提升。在轧材中，使得钢中夹杂物球化，并且钢中硫化锰夹杂物的尺寸和分布也得到了较好的改善，同时，Mg处理能够有效提高易切削钢的切削加工性能。
2021, 42(3): 111-118.
doi: 10.7513/j.issn.1004-7638.2021.03.017
摘要：
以钛石膏、脱硫石膏和钛矿渣三种钛工业固体废弃物为主要原料，石灰作碱性激发剂制作钛石膏复合胶凝材料。采用正交试验，结合XRD、SEM等分析测试方法，对石灰碱激发钛石膏复合胶凝材料强度机理进行分析。结果表明：钛石膏的掺量在42.9%～50.3%，可以制作出强度达到《建筑石膏》（GB/T 9776—2008）2.0强度等级的钛石膏复合胶凝材料。石灰碱激发钛石膏复合胶凝材料的前期强度主要来自钛石膏和脱硫石膏水化产生的二水石膏，后期强度主要来自水泥、石灰和石膏进一步反应产生钙矾石。其水化机理为：第一，CaSO4·0.5H2O水化产生CaSO4·2H2O；第二，水泥中的3CaO·Al2O3与CaSO4·2H2O反应生成钙矾石，石灰与水反应产生Ca(OH)2，结合CaSO4·2H2O和CaO·Al2O3反应产生钙矾石，进一步提升钛石膏复合胶凝材料的强度。
以钛石膏、脱硫石膏和钛矿渣三种钛工业固体废弃物为主要原料，石灰作碱性激发剂制作钛石膏复合胶凝材料。采用正交试验，结合XRD、SEM等分析测试方法，对石灰碱激发钛石膏复合胶凝材料强度机理进行分析。结果表明：钛石膏的掺量在42.9%～50.3%，可以制作出强度达到《建筑石膏》（GB/T 9776—2008）2.0强度等级的钛石膏复合胶凝材料。石灰碱激发钛石膏复合胶凝材料的前期强度主要来自钛石膏和脱硫石膏水化产生的二水石膏，后期强度主要来自水泥、石灰和石膏进一步反应产生钙矾石。其水化机理为：第一，CaSO4·0.5H2O水化产生CaSO4·2H2O；第二，水泥中的3CaO·Al2O3与CaSO4·2H2O反应生成钙矾石，石灰与水反应产生Ca(OH)2，结合CaSO4·2H2O和CaO·Al2O3反应产生钙矾石，进一步提升钛石膏复合胶凝材料的强度。
2023, 44(3): 1-8.
doi: 10.7513/j.issn.1004-7638.2023.03.001
Abstract:
2023, 44(1): 1-3.
doi: 10.7513/j.issn.1004-7638.2023.01.001
Abstract:
