球化铁水中氧的行为与球化衰退的关系

采用自行研制的铁水长期连续测氧探头,测定了球化铁水在共晶温度以上,高温等温保持过程中氧活度及其他冶金因素的变化;探讨了氧活度变化规律与球化衰退的关系。结果表明,球化铁水在高温保持在过程中,氧活度不断增加,而ＲＥ,Ｍｇ,Ｓ含量降低,球化衰退是由于铁水中氧活度的增加,干扰和破坏了球状石墨生长过程引起的,脱硫,脱氧净化处理是有效的防止球化衰退的工艺方法。     

钡,钙在大断面球铁中抗衰退作用研究

试验以武钢生铁为原料，研究了含Ｂａ稀土镁球化剂及含Ｂａ、Ｃａ、Ａｌ硅铁孕育剂和瞬时孕育方法在大断面铸态铁素体球铁中的抗球化衰退作用。实验表明，采取上述措施完全消除了大断面球铁的碎块状石墨，使壁厚为２５０ｍｍ－５００ｍｍ试说球化率达到８５％以上，σｂ〉３００ＭＰａ，δ〉９％，并用Ｂａ、ｃａ形成硫化物及氧化物的热力学稳定性及Ｂａ、Ｃａ对包围石墨球的奥氏体壳的稳定性对抗衰退作用进行分析和讨论。     

镀镍液中微量铁测定的研究

研究了镀镍液中微量铁的测定方法。采用５－溴水扬基荧光酮为是色剂。在ｐＨ５．０－６．０介质中，Ｆｅ与５－ＢＳＡＦ，ＣＴＭＡＢ形成稳定的三元配合物。其最适测定波长在６０５ｎｍ。摩尔吸光系娄ε６０５＝１．４×１０＾５，有色溶液２ｈ内稳定不变，线性范围为０－７μｇ／２５ｍｌ，线性相关系数γ＝０．９９９７，加入回收率在９７．７％－１０３％之间。     

厚大断面球铁件球化率的预测

根据厚大断面球铁件在凝固过程中球化衰退的规律，建立了球化率随时间变化的数学模型，并根据铁水化学成分，球化处理及孕育处理工艺，凝固时间等，用多元回归方程和平方根凝固定律，通过计算机进行了运算。用此数学模型对球铁容器铸件做球化率预测，其结果与实测球化率基本符合，偏差小于３．６％。     

稀土元素在铁水中存在形态对铁水球化和抗衰退性能的影响

在Mg-Si球化剂处理的铁水中加人La-Ce氧化物。然后在SG 2-8-13型保温炉中按大断面铸件凝固条件进行模拟性抗衰退保温试验。由此验证稀土氧化物对铁水的球化和抗衰退性能的影响。结果表明:稀土氧化物的存在对铁水的球化和对球铁的抗衰退性能都是有害的。随球铁铁水中稀土氧化物含量的增加,球化级别下降。抗衰退时间缩短。据此提出了稀土在球铁中的存在形态对铁水球化和抗衰退作用的新认识。     

中韧性铸态球铁的生产工艺

论述了中韧性铸态球铁的化学成分选择，熔化方式、球化处理、孕育处理工艺，并论述了球化衰退、孕育衰退对铸态球铁组织与性能的影响，在工艺上应采取的措施。     

香兰素合成新工艺研究

研究了以对甲酚、溴和过氧化氢等主要原料,经过溴化、甲氧基化和氧化反应合成香兰素的工艺。０．６ｍｏｌ溴和１．０ｍｏｌ过氧化氢在１０℃,４ｈ内滴加到１．５ｍｏｌ对甲酚和１５０ｍＬ甲醇的混合物中,得到１８０ｇ２－溴对甲酚（Ⅰ）;（Ⅰ）与甲醇钠在１４５℃和１．０－１．２ＭＰａ条件下反应２．５ｈ生成１２４ｇ２－甲氧基甲酚（Ⅱ）;（Ⅱ）在乙酸钴存在下,用空气氧化得到４４ｇ香兰素,总收率为７０％。     

球墨铸铁共晶组织生长的计算机模拟

用Ｍｏｎｔｅ Ｃａｒｌｏ法和填充法模拟球铁的共晶生长,在相对生长速率比分别为１．４,２．０,２．４,３．０分析下,模拟对球化率,球墨大小及其组成的影响;同时还研究了Ａ体壳中晶粒数分别为１,２,４条件下,对Ａ体晶粒大小的影响。模拟研究结果表明,模拟组织形象,逼真,快捷,对研究球铁显微组织的形成具有指导作用。     

牛胆中氨基酸的分析

本文采用化学衍生化技术和ＧＣ／ＭＳ／ＭＳＤ分析技术，测定了经干燥后的牛胆中的各种游离氨基酸，色谱分离出２０多个组分，其中鉴定出１７种氨基酸，其主要成分是甘氨酸（２．８８ｍｇ／ｇ），谷氨酸（０．６８ｍｇ／ｇ），亮氨酸（０．２９ｍｇ／ｇ），天门冬氨酸（０．２６ｍｇ／ｇ）。     

计算机模拟Al—Cu—（Mg）—（Ag）时效初期原子分布状态

采用Ｍｏｎｔｅ Ｃａｒｌｏ方法模拟了时效初期Ａｌ－１．８Ｃｕ,Ａｌ－１．８Ｃｕ－０．１Ａｇ。８Ｃｕ－０．５Ｍｇ和Ａｌ－１．８Ｃｕ－０．５Ｍｇ－０．２Ａｇ４种合金的原子分布图。结果表明：在无Ｍｇ,Ａｇ的Ａｌ－Ｃｕ合金时效时,Ｃｕ原子有强烈丛聚的倾向,而微量Ｍｇ,Ａｇ的加入明显抑制了Ｃｕ原子的丛聚,其中,尤以Ｍｇ的作用最为显著,并且Ｍｇ,Ａｇ之间还存在强烈的相互作用。作者认为,微量Ｍｇ,Ａｇ对Ａｌ－Ｃ     

喷粉处理改善球化效果的试验研究

探讨了稀土镁球化剂在喷粉处理时的球化效果，进而对喷粉脱硫、球化、孕育综合处理工艺的球化效果进行了试验研究。结果表明：喷粉球化是一种有效的新球化方法，可获得低硫、低氧、石墨圆整而细小的铸态铁素体球墨铸铁。综合喷粉球化工艺可将脱硫剂、球化剂、孕育剂喷入铁水，完成脱硫、球化、孕育过程。获得的球铁在强度较高的同时，其延伸率和冲击值也很大，使铸态生产高韧性球铁成为可能。     

Numerical simulation on melt flow with bubble stirring and temperature field in aluminum holding furnace

The numerical model for predicting the flow and temperature fields of the melt in holding furnace with porous brick purging system were set up using Euler-Lagrange approach.In this model,bubbles coalescence and disintegration were ignored based on the dimensionless analysis,and the bubble size was assumed to be obedient to Rosin-Rammler distribution with a mean size of 0.6 mm.The results show that on reference operating condition,during the heating and agitation process,melt mixes well in the furnace,and th...     

低热值高炉煤气在发电设备中的应用

高炉煤气是钢铁产业的副产品,其特点是煤气产生量大、可燃物含量少、发热量低,以及燃烧性能差等,在对钢铁企业能源消耗结构和高炉煤气特性火焰传播速度与过量空气系数关系分析研究的基础上,介绍了有效合理利用低热值高炉煤气用于燃气－蒸汽联合循环发电和燃煤－燃气混烧锅炉发电所出现的问题及实际运行状况,得出了机组稳定运行时高炉煤气性质波动的控制范围。     

非真空熔铸铍铜合金大规格铸锭的研究

在非真空熔铸铍铜合金大规格铸锭时,需要长时间的熔化和保温.由于铍在金属熔体中的氧化烧损量达到0.004 4%/min以上,熔体中的铍质量分数处于不断下降的状态,因而不同铸锭之间、同一铸锭头尾w（Be）偏差达到6%以上;铍及铍铜原料的大量烧损容易导致铸锭夹杂,进而影响铸锭的综合成品率;同时,由于铍具有强烈的脱氧作用,熔体极易吸气,铸锭内部容易出现气孔等铸造缺陷.通过上百炉次的试验,对熔铸工艺的每个细节深入研究和试验,确定了合理的熔铸工艺,在生产铍铜合金大规格铸锭时,铍及铍铜材料的烧损率分别降到6%及3%以下,铸锭化学成分偏差≤4%,铸锭综合成品率达到80%以上.     

Desulfurizer desulphurization kinetics by the injection method

To obtain a better desulphurization effect in hot metal, suitable desulfurizers should be selected first according to thermodynamics. However, the effect of desulphurization is also strongly affected by kinetics. The conditions of different desulfurizers (Mg, CaC2, and lime) penetrating into hot metal, the rising up velocity in iron melt, residence time, and dissolving time are theoretically calculated and analyzed. The results are helpful to select the desulphurization process and equipment and to improve the desulphuri-zation effect.     

Microstructure and mechanical properties of high-Cr cast iron bars reinforced Hadfield steel matrix composites

To obtain the compatible material of high hardness and high toughness, Hadfield steel matrix composites, reinforced by high-Cr cast iron bars made of flux-cored welding wires, which were inserted into the Hadfield steel melt, were investigated. The mechanical properties of three materials, i e, composites for as-cast and quenching-water condition, as well as Hadfield steel, were compared. The results show that the alloy powder inside flux-cored welding wires can be melted by the heat capacity of Hadfield steel melt and solidify into high-Cr cast iron bars. The impact toughness of the composite for quenching-water condition is higher than that of the composite for as-cast condition and is lower than that of the Hadfield steel, but it can still meet the requirements of hardness and toughness in industrial application. Regardless of load variation, composite for quenching-water condition shows better wear resistance than those of the composite for as-cast condition and Hadfield steel. The modified fracture toughness and wear resistance of composites are attributed to not only the combining actions of Hadfield steel matrix and high-Cr cast iron bars, but also the effect of heat treatment.     

降低攀钢高炉铁损刍议

简介攀钢高炉历年的生产与铁损情况,分析了攀钢高炉铁损的主要走向及分布,着重分析了其铁损高的主要原因,提出进行综合治理是降低攀钢高炉铁损的有效途径。     

Ignition-proof mechanism of ZM5 magnesium alloy added with rare earth

The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% (mass fraction) rare earth (RE) was investigated. The oxide scales and substrates were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength i...     

The effect of melt overheating on the melt structure transition and solidified structures of Sn-Bi40 alloy

Evolution of the electrical resistivity of Sn-40wt%Bi melt with time under different overheating temperatures during isothermal experiments has been studied, and the relationship between different melt state, solidification behavior and solidified structure has also been investigated. The results show that the melt structure transition revealed by the abnormal change of resistivity would take place within a certain holding time just when the holding temperature is above a certain critical, and that the higher the temperature above the critical, the shorter the “incubation period” of the melt structure transition, and the faster the transition speed. The results of solidification experiments suggest that the melt structure transition caused by different holding time at the same temperature can lead to a higher solidification undercooling degree, finer grain size and change of microscopic pattern. Further exploration indicates that the solidification undercooling degree can come to a head when the melt is held at the specific temperature for a given time. The functionary mechanism of the phenomena above is also discussed briefly. Supported by the National Natural Science Foundation of China (Grant Nos. 50571033, 50371024) and the Natural Science Foundation of Anhui Province(Grant No.070414178)     

用高低温熔体混合法制备Al- 18%Si合金

采用熔体混合法将不同温度的纯铝熔体与600 ℃半固态Al-36%Si合金熔体混合制备Al-18%Si合金,研究纯铝液温度、保温温度和保温时间对Al-18%Si合金初生硅相显微组织及力学性能的影响。实验结果表明:熔体混合法可制得初生硅为颗粒状且均匀分布的Al-18%Si合金;在一定范围内,初生硅的粒径随熔体温差的增大而减小,随保温时间的延长呈先减小后长大的趋势;900 ℃的铝液与600 ℃半固态Al-36%Si合金熔体混合后于750 ℃保温20 min获得的Al-18%Si合金力学性能最好,初生硅平均粒径最小。