The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essentia...The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essential intermediate in V_(2)O_(5)production.This study explores an alternative approach utilizing sodium metavanadate directly,offering an aluminothermic process to alleviate the environmental impact and reduce the time required for V_(2)O_(5)preparation.Al-V alloys are synthesized using sodium metavanadate derived from a shale V-rich solution,and the impurity-migration behaviors are comprehensively analyzed,specifically focusing on Fe,Al,and Na.The result sreveal that Al interacts with CaO to form a slag phase that is different from the alloy,whereas Na undergoes a sequence of reductions (NaVO_(3)→Na_(2)V_(2)O_(5)→NaVO_(2)→Na)and volatilizes at 25-1200℃,thereby avoiding incorporation into the alloy.Fe,reduced by Al,enriches the alloy phase and induces a phase transition(Al-V→Al-Fe→Fe-V)in the presence of excess Fe.Sodium metavanadate(Fe≤0.05wt%)derived from the shale V-rich solution enables the production of a uniform AlV65 alloy with 66.56wt%V,33.14wt%Al,0.08wt%Fe,0.07wt%C,0.02wt%N,and 0.12wt%O.These results establish a streamlined,efficient framework for the future preparation of Al-V alloys from shale V-rich solutions.展开更多
The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margi...The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margin and the V-enriched black shales in deeper slope-basin settings. In this study, we have measured Re-Os isochron ages of Ni-Mo polymetallic layers（Songlin, Niuchang, Sancha, Chuanpengwan）, V-rich black shales（Bahuang）, and non-metalliferous black shales（Shuidong） in the basal Niutitang Formation in Guizhou and Hunan province, South China. The Ni-Mo polymetallic layers and V-enriched black shales have similar Re-Os isochron ages, suggesting concurrent deposition of these two types of metalliferous ores. This suggestion is consistent with the traditional stratigraphic correlation by using the nodular phosphorite bed directly underlying these metalliferous layers as a stratigraphic marker. Furthermore, the metalliferous ores and non-metalliferous black shales have similar initial ^（187）Os/^（188） Os ratios of 0.8-0.9, arguing for a dominant seawater origin with minor contribution of hydrothermal activity. Furthermore, Re-Os isotopic data also imply that Ni-Mo and V ore might have derived from the same source. We suggest that the spatial distribution of metalliferous ores can be explained by the development of non-sulfidic anoxic-suboxic wedge（NSASW） in the slope-basin and sulfidic wedge in the previous platform margin. Upwelling of deep water first transects the mildly reduced, organic rich NSASW, in which V（V） is reduced to V（IV）, and is preferentially removed from seawater by organometallic complex formation. As a result, V-rich black shale deposits in the slope-basin of Yangtze Platform. Further movement of deep water into the sulfidic platform margin results in Ni-Mo polymetallic layer formation.展开更多
采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降...采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降钒工艺增加了细小弥散的钒析出相数量,析出相尺寸为10~30 nm,其中V（CN）析出物占总w（V）的79.35%,析出强化效果显著;钢中夹杂物尺寸小且数量少,A、B、D类夹杂小于1.0级,C类夹杂小于1.5级,有利于控制钢中微裂纹的萌生与扩展,改善钢筋塑韧性;钢筋强屈比（Rm实/ReL实）不小于1.27,均匀伸长率（Agt）不小于12%,抗震性能好;自然时效1个月后强度变化平缓,具有低应变时效性;焊接试样断口远离焊接接头、焊接性能良好;生产成本和钒氮微合金化工艺相比吨钢降低20元。展开更多
基金funded by the National Key R&D Pro-gram of China (No.2023YFC3903903)the Science and Technology Innovation Talent Program of Hubei Province,China (No.2022EJD002).
文摘The use of Al-V alloys as intermediate additives is pivotal for producing high-performance Ti alloys.Traditionally,the synthesis of these alloys relies on high-purity V_(2)O_(5),with sodium metavanadate as an essential intermediate in V_(2)O_(5)production.This study explores an alternative approach utilizing sodium metavanadate directly,offering an aluminothermic process to alleviate the environmental impact and reduce the time required for V_(2)O_(5)preparation.Al-V alloys are synthesized using sodium metavanadate derived from a shale V-rich solution,and the impurity-migration behaviors are comprehensively analyzed,specifically focusing on Fe,Al,and Na.The result sreveal that Al interacts with CaO to form a slag phase that is different from the alloy,whereas Na undergoes a sequence of reductions (NaVO_(3)→Na_(2)V_(2)O_(5)→NaVO_(2)→Na)and volatilizes at 25-1200℃,thereby avoiding incorporation into the alloy.Fe,reduced by Al,enriches the alloy phase and induces a phase transition(Al-V→Al-Fe→Fe-V)in the presence of excess Fe.Sodium metavanadate(Fe≤0.05wt%)derived from the shale V-rich solution enables the production of a uniform AlV65 alloy with 66.56wt%V,33.14wt%Al,0.08wt%Fe,0.07wt%C,0.02wt%N,and 0.12wt%O.These results establish a streamlined,efficient framework for the future preparation of Al-V alloys from shale V-rich solutions.
基金supported by the National Natural science Foundation of China (Nos. 41203037, 41272017, 41472089, 41402025)the Chinese Geological Survey Program (Nos. 12120113015500, 12120114039701, 1212010633903, 1212011120622, J(2010)KP010705)+2 种基金Laboratory of Paleontology and Stratigraphy Open-lab grant (133103)the Science and Technology Foundation of Guizhou (No. QKHJZ(2012)2163)the Talents Introduction Foundation of Guizhou University (No. GDRJHZ(2011)17)
文摘The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margin and the V-enriched black shales in deeper slope-basin settings. In this study, we have measured Re-Os isochron ages of Ni-Mo polymetallic layers（Songlin, Niuchang, Sancha, Chuanpengwan）, V-rich black shales（Bahuang）, and non-metalliferous black shales（Shuidong） in the basal Niutitang Formation in Guizhou and Hunan province, South China. The Ni-Mo polymetallic layers and V-enriched black shales have similar Re-Os isochron ages, suggesting concurrent deposition of these two types of metalliferous ores. This suggestion is consistent with the traditional stratigraphic correlation by using the nodular phosphorite bed directly underlying these metalliferous layers as a stratigraphic marker. Furthermore, the metalliferous ores and non-metalliferous black shales have similar initial ^（187）Os/^（188） Os ratios of 0.8-0.9, arguing for a dominant seawater origin with minor contribution of hydrothermal activity. Furthermore, Re-Os isotopic data also imply that Ni-Mo and V ore might have derived from the same source. We suggest that the spatial distribution of metalliferous ores can be explained by the development of non-sulfidic anoxic-suboxic wedge（NSASW） in the slope-basin and sulfidic wedge in the previous platform margin. Upwelling of deep water first transects the mildly reduced, organic rich NSASW, in which V（V） is reduced to V（IV）, and is preferentially removed from seawater by organometallic complex formation. As a result, V-rich black shale deposits in the slope-basin of Yangtze Platform. Further movement of deep water into the sulfidic platform margin results in Ni-Mo polymetallic layer formation.
文摘采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降钒工艺增加了细小弥散的钒析出相数量,析出相尺寸为10~30 nm,其中V（CN）析出物占总w（V）的79.35%,析出强化效果显著;钢中夹杂物尺寸小且数量少,A、B、D类夹杂小于1.0级,C类夹杂小于1.5级,有利于控制钢中微裂纹的萌生与扩展,改善钢筋塑韧性;钢筋强屈比（Rm实/ReL实）不小于1.27,均匀伸长率（Agt）不小于12%,抗震性能好;自然时效1个月后强度变化平缓,具有低应变时效性;焊接试样断口远离焊接接头、焊接性能良好;生产成本和钒氮微合金化工艺相比吨钢降低20元。
