含钡合金对冷镦钢脱氧的试验研究

在250kg感应炉上对冷镦钢进行了含钡合金脱氧的试验研究。试验中钡系合金主要选取SiAlBaCa和SiAlBaCaSr及用于钙处理的SiCa、SiCaBa包芯线。选用FeSiAl作为对比脱氧剂，考察了钡系合金脱氧的全氧含量，脱氧产物的分布、尺寸和形貌，探讨了钡系合金脱氧和对夹杂物的变质作用的机理。试验中发现，含钡合金用于钢液脱氧，可获得较低的氧含量，其脱氧产物易于上浮且速度很快，钢中的夹杂物形态发生改善呈球形，而且均匀分布于钢中。     

硅铝钡合金对轴承钢脱氧实验研究

分别采用低钡和高钡合金对轴承钢进行脱氧和夹杂变形处理实验，结果表明，高钡合金的脱氧和夹杂物变性及去除能力均优于低钡合金；两种合金处理后，钢中均无含钡点状夹杂，从而为ＬＦ炉中直接采用钡系合金处理轴承钢提供依据。     

含钡合金的生产及其对钢液脱氧行为的研究

介绍了含钡合金的生产状况。在MoSi2炉上对钢管钢进行了含钡合金脱氧行为的研究，然后在150tLF／VD精炼设备上进行了使用含钡合金的工业试验。研究中主要选取SiAlBa、SiCaBa、SiAlBaCa、SiAlBaCaSr及用于钙处理的SiCa包芯线，并选用Al和FeSiAl作为对比脱氧剂，分别考察了实验室条件下和实际生产过程中，采用钡系合金对钢液脱氧的全氧含量，脱氧产物的分布、尺寸和形貌，探讨了钡系合金脱氧和对夹杂物的变质作用的机理。     

钡系合金脱氧基础研究

本文对钡及钡合金进行了理论研究，探讨了钡合金脱氧，脱硫等精炼效果及应用的可行性，通过实验测定了硅钡，硅钙钡两种钡合金的脱氧及脱硫能力曲线。     

钡系复合合金对钢液脱氧行为的试验研究

在实验室研究的基础上,在LF／VD精炼设备上进行了钡系合金对钢液的脱氧工业试验。试验发现采用SiAlBaCa脱氧时的全氧含量基本上在各个工位均低于采用Al和FeSiAl脱氧,其脱氧产物上浮速度要快于用Al脱氧,能够较快地使夹杂物数量达到较低的水平,且试验中夹杂物的球化作用比较明显,同时还探讨了钡系合金脱氧和对夹杂物的变质作用机理。     

用钡合金对齿轮钢脱氧的工艺研究

为提高钢的洁净度,在50t EAF-60 t LF流程中采用钡合金对齿轮钢进行脱氧试验,通过控制电炉出钢碳含量、充分地铝预脱氧并用钡合金进行终脱氧和夹杂物变性,可使铬铝系SCM822H齿轮钢的氧含量降至0．0015％以下。     

钡合金对钢脱氧及夹杂物变性影响的理论分析

在比较各种常用脱氧剂单项脱氧能力的基础上，对硅钡、铝钡的复合脱氧能力，钡对夹杂物变性能力和生成液态夹杂的影响进行了分析，并推荐了钡合金的成分。     

炼钢用Si-Ca-Ba复合脱氧剂成分优化的研究

在实验室条件下考察了不同钡、钙质量分数的Si-Ca-Ba合金对钢液脱氧和夹杂物变性作用的变化规律。实验发现，当Si-Ca-Ba合金中钡、钙增加时，脱氧终点钢液中的全氧降低，但合金中钡的增加对降低终点钢液全氧的贡献不大。合金中的钡钙比对于降低钢液中夹杂物的尺寸至关重要，当Si-Ca-Ba合金中钡钙比约为2．7～3．5时，夹杂物的尺寸取得最小值。     

矿热炉冶炼硅钙钡铝合金

硅钙钡铝合金为钡系合金中高级复合合金,是含钡合金中强脱氧,脱硫剂。它是特殊钢常用的终脱氧剂,使钢中的氧达到最低(4.3ppm);同时形成含钙、钡、铝等复杂夹杂物易从钢中上浮,纯洁钢液,提高钢的内在质量。目前生产方法有:(1)硅铝合金冶炼加入石灰、钡矿而成硅钙钡铝合金;(2)分层法冶炼硅钙钡合金加入铝土矿而成     

钡合金在钢中的应用

本文对有关钡及钡合金的理论研究和实际应用进行了综述,探讨了钡合金应用中存在的问题,指出钡合金具有脱氧、脱硫、使夹杂物变性和实现微合金化的综合精炼效果,具有广泛的应用前景。提出了进一步着重研究的方向。     

Combined Effect of Calcium and Silicon on the Phase Composition and Structure of Al–10%Mg Alloy

Phase transformations in the Al–Ca–Mg–Si system in the region of aluminum–magnesium alloys are investigated using the Thermo-Calc program. The liquidus projection of the quaternary system is constructed with a Mg content of 10% and it is shown that phases Al4Ca, Mg₂Si, and Al₂CaSi₂ can crystallize (in addition to the aluminum solid solution (Al)) depending on the calcium and silicon concentrations. The crystallization character of quaternary alloys is investigated with the help of a polythermal cross section calculated at concentrations of 10% Mg and 84% Al. Based on the analysis of phase transformations occurring in alloys of this section, the presence of the Al–Al₂CaSi₂–Mg₂Si quasi-ternary section in the Al–Ca–Mg–Si system was assumed. Three experimental alloys were considered from a quantitative analysis of the phase composition, notably, Al–10% Ca–10% Mg–2% Si, Al–4% Ca–10% Mg–2% Si, and Al–3% Ca–10% Mg–1% Si. Metallographic investigations and electron-probe microanalysis were performed using a TESCAN Vega 3 scanning electron microscope. Critical temperatures are determined using a DSC Setaram Setsys Evolution differential calorimeter. The experimental results agree well with the calculated data; in particular, a peak at t ~ 450°C is revealed for all alloys in curves of the nonequilibrium solidus and invariant eutectic reaction L → (Al) + Al₄Ca + Mg₂Si + Al₃Mg₂. It is established that the structure of the Al–3% Ca–10% Mg–1% Si alloy is closest to the eutectic alloy. It is no worse that the AMg10 alloy in regards to density and corrosion resistance and even surpasses it in hardness, which allows us to consider this alloy as the basis for the development of a new cast material: “natural composites.”     

Effects of AlMnCa and AlMnFe Alloys on Deoxidization of Low Carbon and Low Silicon Aluminum Killed Steels

 To confirm the effects of AlMnCa and AlMnFe alloys on the deoxidization and modification of Al2O3 inclusions, experiments of 4 heat low carbon and low silicon aluminum killed steels deoxidized by AlMnCa and AlMnFe alloys were done in a MoSi2 furnace at 1 873 K. It is found that the 1# AlMnCa alloy has the best ability of deoxidization and modification of Al2O3 inclusions than 2# AlMnCa and AlMnFe alloys. Steel A deoxidized by 1# AlMnCa alloy has the lowest total oxygen content in the terminal steel, which is 37×10-6. Most of the inclusions in the steel deoxidized by 1# AlMnCa alloy are spherical CaO containing compound inclusions, and 891% of them are smaller than 10 μm. The diameter of the inclusion bigger than 50 μm is not found in the final steels deoxidized by AlMnCa alloys. Whereas, for the steels deoxidized by AlMnFe alloys, most inclusions in the terminal steel are Al2O3 or Al2O3 MnO inclusions, and a few of them are spherical, and only 768% of them are smaller than 10 μm. Some inclusions bigger than 50 μm are found in the steel D deoxidized by AlMnFe alloy.     

Process Technological Develpoments for Improvement of the Castability of High‐Carbon Steels

Steels for rail‐making involve standard requirements concerning oxide cleanness. Castability problems do not generally occur. Due to the extremely high demands on cleanness, roller‐bearing steel 100Cr6 is cast using narrow SENs, which are extremely susceptible to clogging. Problems caused by clogging occur despite the fact that these heats are deoxidized using C, Si and Mn, with no addition of Al. Castability improved significantly after conversion to low‐Al ferrosilicon for deoxidation and rinsing of ladles with carbon‐deoxidized preceding heats. Casting temperature with a superheat of 30°C and a reduction in Al content to less than 20 ppm made it possible to increase sequence length to three heats.     

The role of solute in grain refinement of magnesium

The effect of separate solute additions of Al, Zr, Sr, Si, and Ca on grain size of Mg has been investigated. Increasing the Al content in hypoeutectic Mg-Al alloys resulted in a continuous reduction in grain size up to 5 wt pct Al, reaching a relatively constant grain size for higher Al contents (above 5 wt pct). The effect of Sr additions was investigated in both low- and high-Al content magnesium alloys, and it was found that Sr had a significant grain refining effect in low-Al containing alloys but a negligible effect on grain size in Mg-9Al. Additions of Zr, Si, and Ca to pure magnesium resulted in efficient grain refinement. The grain refinement is mainly caused by their growth restriction effects, i.e., constitutional undercooling, during solidification, but the effect of nucleant particles, either introduced with the alloying additions or as secondary phases formed as a result of these additions, may enhance the grain refinement. A brief review of grain refinement of magnesium alloys is included in this article to provide an update on research in this field.     

用含钡合金对不锈钢脱氧、脱硫和还原脱磷

在MoSi2炉和MgO坩埚内进行了含钡合金处理316L不锈钢液的实验研究.实验选用的含钡合金为SiCaBa、SiAlBaCa和SiCaBaMg,并与SiCa和AlCa合金的处理结果进行了对比.实验中发现,使用含钡合金处理钢液时,钡在处理初期就参与了脱氧反应,生成含钡的复合氧-硫化物夹杂,更易于上浮排除,全氧含量能够快速降低至较低的水平;在钙合金中添加钡、镁等元素后,合金的脱硫能力提高;SiCaBa合金的还原脱磷效果最佳,用SiAlBaCa合金处理钢液时未出现回磷现象.     

电渣重熔钢中非金属夹杂物含量及成分的控制

在电渣重熔过程中，控制自耗电极冶炼的脱氧制度并配合电渣重熔渣系的选择，可以有目的地控制电渣重熔钢中非金属夹杂物的含量和成分。对于滚珠轴承钢ＺＧＣｒ１５，当自耗电极用钢采用Ｓｉ－Ｆｅ、Ｓｉ－Ｃａ脱氧并用酸性渣重熔可以获得最佳精炼效果，使钢中夹杂物转变为硅酸盐类塑性夹杂物。上述结论在工业生产中已得到验证。     

Effect of scandium on the phase composition and hardening of casting aluminum alloys of the Al–Ca–Si system

The phase composition of the Al–Ca–Si–Sc system is investigated in aluminum corner uisng computational (Thermo-Calc) and experimental (optical microscopy, scanning electron microscopy, and electron probe microanalysis) methods. The influence of annealing on the structure and hardness of alloys containing 0.3 wt % Sc is investigated in the region up to 550°C. It is shown that the maximum in the hardening curve caused by the isolation of nanoparticles of the Al₃Sc (L1₂) is attained after annealing at temperatures of 300–350°C in alloys belonging to the phase region (Al) + Al₄Ca + Al₂Si₂Ca ((Al) is the aluminum-based solid solution). Scandium completely enters the (Al) composition in alloys of this region, while the silicon concentration is minimal in it. On the other hand, hardening is almost absent in alloys from the (Al) + (Si) + Al₂Si₂Ca phase region. The possibility in principle to form the casting alloys based on the (Al) + Al₄Ca + Al₂Si₂Ca eutectic hardened without quenching is substantiated.     

电感耦合等离子体原子发射光谱法测定硅铝钡钙系列合金主元素

探讨了用电感耦合等离子体原子发射光谱(ICP-AES)法同时测定硅铝钡钙合金中的主元素Si、Al、Ba、Ca的分析条件并建立了测定方法。硅铝钡钙合金样品用硼酸-无水碳酸钠混合熔剂高温熔融、盐酸浸取和酸化的处理流程,样品前处理时间由原来的5~6 h缩短到45 min之内。通过试验选择了Si 251.611 nm、Al 396.152 nm、Ba 233.527 nm、Ca 317.933 nm光谱线作为分析线。在选择的仪器最佳工作参数和试验条件下,对一组国家标准样品进行测定,硅、铝、钡、钙4种元素测定值与认定值基本一致,相对标准偏差在0.12%~0.63%范围内,相对误差<3%。