60Si2Mn钢中硅的回收率探析

60Si2Mn是一种含硅量很高的弹簧钢,在大量的工业生产过程中往往容易出现硅回收率偏低、回收率波动值过大的问题。据此,着重研究讨论了合金化时间、钢液温度、（FeO）含量以及渣量对硅的回收率的影响。提出了对应的措施。     

硅锰合金生产中适宜炉渣碱度的选择

讨论了硅锰合金生产中锰(硅)回收率、渣量和产品单位电耗与炉渣碱度的关系,得出了本试验条件下适宜的炉渣碱度((CaO+MgO)/(SiO_2)))为0.75。通过论证硅回收率与碱度的关系,指出提高硅回收率将有利于锰回收率的提高。     

锰硅合金炉渣中锰回收率的影响因素

根据电炉冶炼锰硅合金的实际生产经验,分析了锰硅合金生产过程中影响锰硅合金炉渣含锰量的主要因素。同时指出,只要把这些主要因素控制在合适的范围内,就可降低渣中的含锰量,提高锰的回收率。     

煤矸石在调整锰硅渣型中的应用

为降低锰硅生产成本,对煤矸石在锰硅合金生产中的应用进行了介绍,从理论和生产实践两方面阐述了使用煤矸石调整锰硅合金渣型,实现高Al_2O_3渣的低渣比操作的可行性。根据生产实际阐述了煤矸石配入量对渣铁比、渣中跑锰、硅石利用率的影响,并分析了渣中各组元之间的相互关系。最终采用高煤矸石配人量、高人炉品位生产锰硅合金,结果表明,煤矸石对提高锰硅回收率、降低电耗均有一定的作用。     

钼蓝分光光度法测定铅锭中硅的条件优化设计

采用钼蓝分光光度法测定铅锭中硅含量,研究了溶样试剂、显色酸度、钼酸铵加入量、还原液加入量以及基体效应等因素的影响,确定了最佳实验条件。对实际样品中硅含量测定的相对标准偏差(RSD, n=10)在2%左右,测得加标回收率在96.5%～104.8%之间。该方法操作简单,分析流程短,具有较高的精密度和准确度,能够满足铅锭中硅的测定。     

粉煤灰、铝土矿电热法生产铝硅铁合金的试验

为改善环境，合理利用资源，应用粉煤灰、铝土矿、碳粉混合造球，球团干燥后放入中频感应炉进行熔炼，熔炼过程中加入铁矿粉和生铁块。研究结果表明：合金中铝的含量越高，其回收率越低。合金中铝的含量为24．67％时，铝的回收率高达61．91％，硅含量为18．42％时，硅的回收率高达92．51％。影响铝、硅回收率的主要因素为配铁量、熔炼温度和还原剂用量，熔炼温度控制在1800—1900℃为宜。     

不加硅石冶炼锰硅合金的探讨

分析了在锰硅电炉冶炼过程中影响SiO2还原的因素.当SiO2的还原率高,混合锰矿中SiO2含量适当时,可以实现不加硅石冶炼锰硅合金.在设定Si回收率条件下,对混合锰矿中应含SiO2的量进行了计算,并介绍了冶炼锰硅不加硅石的生产实践.     

侧吹炉技术优化操作实践

介绍了侧吹炉的操作技术和生产实践,采用提高供氧量、增加投矿量、降低焦炭和粉煤量、粉煤替代焦炭技术、提高高硅矿的配比、降低熔剂率、改造侧吹炉放铜口、降低电炉渣含铜等优化措施,降低生产成本,提高金属回收率,实现效益最大化。     

铬铁含碳量的炉前快速分析——“测硅计”

微炭铬铁与中、低炭铬铁的产品合格率是铬铁生产的重要指标之一。国家标准中规定微炭铬铁含硅量不大于2%,中、低炭铬铁含硅量不大于3%。我厂现行的光谱分析硅含量,只作成品分析,不能指导现场出炉。为进一步提高铬铁的合格率,进而提高铬的回收率,我们最近试制成功一台“测硅计”,作为铬铁出铁前的快速分析仪器。经过一个阶段的使用,证明效果较好,操作简便,炉前铬铁样直接放在仪器上,几秒钟后指针即可稳定指示出含硅量;精度基本上能     

ICP-AES法测定硅锰合金中的硅

用硝酸和氢氟酸溶解试样,采用耐氢氟酸雾化装置,用ICP-AES法测定硅锰合金中的硅。选择的最佳仪器工作条件为：长波积分时间15s、短波积分时间15s、雾化气流量30L/min、分析泵速100mL/min、辅助气流量1.0L/min、射频功率950W、试样冲洗时间30s,分析谱线212.412nm,试样粒度应在88μm以下。方法RSD（n=10）为0.2526%,硅回收率99.03%～100.8%,操作简便,分析周期短,能满足硅锰合金中硅的测定要求。     

P、Sr、RE变质对过共晶Al-Si合金组织形态的影响

采用P、Sr、混合RE对含Si量22%～26%的过共晶铝硅合金进行变质处理,利用金相显微镜分析了单一元素变质及复合变质对合金初晶硅和共晶硅组织形态的影响。结果表明,P为初晶硅变质元素,Sr为共晶硅变质元素,RE能同时细化初晶硅和共晶硅;试验发现Sr虽然不能细化初晶硅,但对初晶硅有明显的裂解作用;P和RE复合变质使得初晶硅尺寸减小到25μm,而加入Sr后,由于Sr对初晶硅的裂解作用,使得初晶硅的尺寸减小到15μm,共晶硅大部分呈蠕球杆状或团球状,均匀弥散分布;试验得到了一种初晶硅和共晶硅细化效果均良好的复合变质剂。     

Influence of silicon,aluminium, phosphorus and copper on the phase transformations of low alloyed TRIP‐steels

Although silicon is very Important to prevent carbide precipitation during annealing of low‐alloyed TRIP‐steels and thus allows the austenite to be stabilized by carbon, it causes problems during processing. Therefore, other alloying elements having a similar effect as silicon have to be considered. Possible candidates to substitute or reduce silicon are aluminium, copper and/or phosphorus, which are supposed to be capable of suppressing carbide formation, too. The influence of reduced silicon contents in combination with alloying elements being capable of substituting silicon completely or partially on the phase transformations occurring during heat treatment is studied. The results of the investigations are compared with a conventional low alloyed TRIP‐steel. The phase transformations are investigated by dilatometric measurements on cold rolled material. The influence of the cooling rate after the intercritical annealing on the transformation behaviour of the austenite upon cooling and isothermal holding in the bainitic range is studied. The interpretation of the phase transformations are supported by investigations of the microstructure via light microscopy and measuring the content of retained austenite using a magnetic volumetric method.     

Surface of powders of silicon nitride produced by self-propagating high-temperature synthesis

Conclusions The surface of a starting silicon powder used in the production of silicon nitride by the SHS method is covered with an oxide film whose thickness varies, depending on the method of comminution and time of storage of the powder, in the range 1–12 nm. During SHS the Si + SiO₂ reaction results in the formation of gaseous SiO, which becomes adsorbed on the cold walls of the reactor and then experiences disproportionation. This lowers the oxygen content of the resultant silicon nitride, but the overall purification effect achieved is small. After comminution, a 1- to 2-mm-thick layer of powdered silicon nitride produced by SHS consists of a silicon oxynitride with an oxygen content of 5–30 wt.%. Milling conditions do not significantly affect the concentration of oxygen inside the nitride particles, which does not exceed 0.4%. To obtain silicon nitride of low oxygen content, it is necessary to employ starting reactants of high purity.Translated from Poroshkovaya Metallurgiya, No. 1(253), pp. 48–54, January, 1984.     

硅锰铁合金在EBT电炉上的应用

石横特殊钢厂在ＥＢＴ电炉上采用硅锰铁合金复合脱氧合金化工艺,较好地解决了钢水结瘤和钢水脱氧不良的问题,确保了连铸生产顺行,提高了铸坯质量,降低了生产成本。     

阶段平衡降温法提取硅的研究

研究阶段降温法提取硅的最佳工艺条件,考察合金在凝固过程中的保温温度、保温间隔时间、降温幅度及搅拌速度对初生硅生长及分布规律的影响,并比较不同终止温度和搅拌情况下的提取率。结果表明,当保温温度为900℃,降温幅度为10℃,保温间隔时间为20min时,硅的平均直径达到0.466mm,粒径大于3.35mm所占比例达到20.2%;当搅拌速度为50r/min,终止温度为640℃时,通过搅拌的方法提取的合金含硅量高达44.3%。     

钼蓝光度法测定铝及铝合金中硅的含量

介绍了用钼蓝光度法测定铝及铝合金中硅含量的方法。铝合金样品用氢氧化钠分解,硝酸酸化。在弱酸性溶液中,加入钼酸铵,使硅酸根离子与钼酸根离子形成黄色络合物,在硫酸介质中用抗坏血酸还原成硅钼蓝,测定其吸光度。结果表明：该方法操作简单,测定铝及铝合金中硅的含量范围广（0.1%～12%）。方法的稳定性、重现性和准确性都良好,能满足铝及铝合金中硅含量的分析检测要求。     

Thermodynamic Calculations of Melt in Melt Pool During Laser Cladding High Silicon Coatings

Based on the Miedema＇s formation heat model for binary alloys and the Toop＇s asymmetric model for ternary alloys, the formation heat, excess entropy, and activity coefficients of silicon ranging from 1 900 K to 4 100 K in the Fe-Si-C melt formed during the laser cladding high silicon coatings process were calculated. The results indicated that all values of lnγ^0Si, ε^CSi,ρ^SiSi and ρ^CSi are negative in the temperature range and these values increase as the temperature increases. And all values of ε^SiSi and ρ^Si-CSi are positive and these values decrease with increasing temperature. The iso-activity lines of silicon are distributed axisymmetrically to the incident laser beam in the melt pool vertical to the laser scanning direction. And the iso-activity lines of silicon in the front of the melt pool along the laser scanning direction are more intensive than those in the back of the melt pool. The activity of silicon on the bottom of the melt pool is lower than that in the effecting center of laser beam on the top surface of the melt pool and it may be the important reason for the formation of the silicides and excellent metallurgical bonding between the laser cladding coating and the substrate.     

SPHC钢LF精炼过程的抑制回硅与脱硫研究

生产SPHC钢在LF处理脱硫过程中不能抑制回硅.根据热力学理论推导出降硅参数A/S和脱硫参数C/A,应用共存理论作用浓度模型,在试验渣系成分范围内计算CaO、SiO2、Al2O3的活度求解A/S和C/A,探讨了它们与w(CaO)/w(Al2O3)、w(CaO)/w(SiO2)的关系.分析结果认为,控制w(CaO)/w(Al2O3)、w(CaO)/w(SiO2)在合适的范围内,可以有效地分别或同时抑制回硅和脱硫.与试验结果对照得知,A/S和C/A分别与LF渣系的抑制回硅和脱硫能力相对应,根据A/S和C/A进行控制是可行的.     

Effect of the structure of ferrosilicon on its desintegration

The structure of commercial high-percentage ferrosilicon is analyzed. Chemical, X-ray diffraction, and electron-probe analyses are used to compare the self-desintegrated and intact ferrosilicon FS65 alloys manufactured at JSC Serov Ferroalloy Plant. The experimental results demonstrate a significant microheterogeneity caused by silicon segregation, which induces cracking in the alloy structure, and by the existence of magnesium, aluminum, titanium, and silicon phosphides, which can form phosphines during interaction with air moisture. To decrease the spontaneous desintegration of ferrosilicon, it is necessary to suppress segregation before casting, to optimize the silicon content range, and to decrease the concentrations of impurities (mainly phosphorus and aluminum, which are introduced into an alloy with charge materials).