微合金钢中钛析出相的氯化钾-柠檬酸体系提取及各相的分离测定

对含钛微合金钢的钛相进行分离和测定,建立了一种快速分离微合金钢中钛析出相的定量方法。通过优化试验选择75g/L氯化钾溶液-5g/L柠檬酸-去离子水体系代替传统的甲醇电解液提取微合金钢中钛析出相,于0℃电解可以克服低温电解速度慢的问题。用2.4mol/L HCl分解细粒碳化钛,1mol/L HNO₃分解粗粒碳化钛,硝酸和过氧化氢分解氮化钛,采用电感耦合等离子体原子发射光谱法(ICP-AES)测定各相中钛的含量。差减法得到固溶钛以及用碳硫分析仪测定残渣中硫含量换算得到硫化钛含量。细粒碳化钛占钛相的34.27%,粗粒碳化钛占钛相的22.38%,氮化钛占钛相的14.68%,硫化钛占钛相的6.29%,固溶钛占钛相的16.78%。方法的钛析出相回收率为94.41%。     

络合滴定法测定球墨铸铁脱氧剂中钙镁钡

根据球墨铸铁脱氧剂的特性,以硝酸-氢氟酸分解试样,采用高氯酸除去样品中的硅,以氨-氯化铵-过氧化氢-铜试剂沉淀分离稀土、锰、铁和钛等干扰元素后,用EDTA、DCTA络合滴定法分别测定样品中的钙、钙钡合量及镁元素含量,用差减法求得钡元素的含量。讨论了溶样方法、指示剂选择、杂质元素的干扰情况及其消除方法,确定了最佳实验条件。采用本方法对与球墨铸铁脱氧剂成分相似的稀土中间合金标准样品中的钙、镁、钡实验进行多次平行测定,测定值与认定值相符,测定结果的相对标准偏差(RSD ,n=5)为1.2%~3.6%。     

碱熔-EDTA滴定法测定铬铁矿中钙和镁

用过氧化钠熔融分解试样,在强碱性条件下沉淀分离基体及铬、硅,控制溶液pH 6~7,用六次甲基四胺和铜试剂沉淀分离铁、铝、钛等干扰元素,再采用两种不同浓度的EDTA标准滴定溶液对滤液中的钙(以氧化钙计)和镁(以氧化镁计)分别进行滴定,建立了测定铬铁矿中钙和镁的方法。采用电感耦合等离子体原子发射光谱法(ICP-AES)对沉淀法分离铬后滤液中的钙进行了测定,结果表明,滤液中钙含量与样品中钙含量相比可忽略不计。干扰试验表明,试样中的共存元素均不干扰测定。按照实验方法对GTK-1铬铁矿样品、GBW 07820GCr-3铬铁矿标准物质和GSBD 33001-94铬铁矿标准物质中钙和镁进行测定,测定值与认定值一致,结果的相对标准偏差(RSD,n=8)在0.25%～4.9%之间,方法的极差在GB/T 24221-2009规定的允许差范围内。     

微波消解-电感耦合等离子体原子发射光谱法测定铂铑系列合金中铑

提出了试样经微波消解后用电感耦合等离子体原子发射光谱法（ICP AES）测定铂铑系列合金中铑的分析方法。对试样的微波消解条件、基体和谱线干扰等进行研究。结果表明,在230℃温度下,以盐酸和少许过氧化氢、硝酸和氢氟酸为消解试剂,试样在密闭容器中分两次进行消解60 min可以完全溶解。消解液用ICP AES测定时,通过选择合适的分析谱线可避免基体和光谱干扰。用本方法测定了系列铂铑合金的模拟试样,测定结果与行业标准方法的分析结果相一致,相对误差在010%～030%之间,相对标准偏差小于066%（n=6）。该法可以用于铂铑系列合金中铑含量的测定。     

火焰原子吸收光谱法测定银精矿中低含量铜

建立了火焰原子吸收光谱法测定银精矿中低含量铜的测定方法。利用盐酸、硝酸分解试样,用氢氟酸除去试样中的SiO_2,用高氯酸除去试样中的C,用盐酸-氢溴酸混合酸(1+2)除去试样中的Sb,试样分解完全,用二乙烯三胺络合高含量的银,以10%盐酸作介质,溶液澄清,用火焰原子吸收光谱进行测定。方法检出限为0.0104μg/m L,样品加标回收率为98.4%-104.9%,样品结果的相对标准偏差为0.72%-2.55%。该方法可作为铜含量为0.05%-2.0%的银精矿中铜测定的分析方法。     

钒钛高炉渣中碳化钛测定方法的研究

本文对钒钛高炉渣中碳化钛的测定方法进行了探讨和研究。先用H_2SO_4+HF漫取,破坏钙钛矿、钛铁矿、黑钛石等钛化物使其与碳化钛等分离;再用HCl+KClO_3破坏碳化物使其与氮化钛、金红石等分离。分离后的滤液,用二安替比林甲烷分光光度法测定钛,换算为碳化钛的含量。根据岩相鉴定,拟定的方法是可靠的,操作简便,符合工艺流程规律的要求。     

苯基荧光酮光度法测定硅铁合金中痕量锡

硅铁合金试样以王水—氢氟酸分解 ,硫酸冒烟驱除残余氢氟酸 ,用铍载体沉淀分离 -苯基荧光酮光度法进行痕量锡的测定 ,加标回收及标样分析结果令人满意。该法准确、可靠 ,可测定硅铁合金中低至 0.0 0 0 1 %的锡。     

硫酸亚铁铵滴定法测定钛铝钒合金中钒

应用硫酸亚铁铵滴定法测定钛铝钒合金中钒时,存在试样较难溶解且试样中较高含量钛易水解干扰终点颜色判断的问题。实验采用硝酸-氢氟酸-硫酸体系溶解试样,通过加入氢氧化钠使其与基体钛发生反应生成三钛酸钠沉淀的方法实现了钛与钒的分离,于硫-磷混酸介质中,用高锰酸钾将滤液中的钒全部氧化为五价钒,以亚硝酸钠还原过量的高锰酸钾,再用尿素分解多余的亚硝酸钠,以N-苯代邻氨基苯甲酸为指示剂,用硫酸亚铁铵标准溶液滴定钒,建立了硫酸亚铁铵滴定法测定钛铝钒合金中钒的方法。共存元素干扰试验说明试样中的共存元素不干扰测定。将实验方法应用于测定两个钛铝钒合金试样中的钒(质量分数在3%~6%之间),结果的相对标准偏差(RSD,n=6)为0.20%和0.25%。按照实验方法测定6个钛铝钒合金试样中钒,结果与火焰原子吸收光谱法(FAAS)测定值相一致。     

丁二酮肟分光光度法测定锆及锆合金中镍

采用氢氟酸-硝酸体系溶解试样,硼酸饱和溶液中和试样溶解后体系中过量的氢氟酸,再以柠檬酸为络合剂,碘为氧化剂,丁二酮肟为显色剂,基于丁二酮肟与镍形成酒红色络合物,建立了锆及锆合金中镍含量的测定方法。重点考察了氢氟酸用量对测定的影响,结果表明,采用以下氢氟酸用量可保证试样溶解完全:当试样量不大于1.0g时,选用2.5mL氢氟酸;当试样量为2.0g时,选用5.0mL氢氟酸。对实验条件进行优化,结果表明,在优化的实验条件下,镍的质量分数在0.002%~0.15%范围内与其吸光度呈线性关系,相关系数为0.9999,方法的检出限为0.01μg/mL,测定下限为0.04μg/mL。考察了锆基体与共存元素对镍测定的影响,结果表明:锆基体与共存元素对镍的测定无影响。按照实验方法测定锆合金标准样品和4种锆及锆合金合成试样中镍,测定结果与电感耦合等离子体原子发射光谱法(ICP-AES)基本一致,且锆合金标准样品测定结果与认定值一致,所测结果的相对标准偏差(RSD,n=11)为2.9%~10.5%。     

火焰原子吸收光谱法测定镍基体料炉渣中锰

采用盐酸-硝酸-氢氟酸-高氯酸分解试样,若试样还不能溶解完全,则再加5 mL硝酸冒烟至棕红色烟雾消失,加水微沸溶解,再用高氯酸调节pH值至0.5,采用火焰原子吸收光谱法(FAAS)进行测定,建立了镍基体料炉渣中锰的测定方法。在选定仪器条件下,锰的质量浓度与吸光度呈良好的线性关系,特征浓度和精密度符合检测要求,线性回归方程为Y＝0.170 1X+0.015 33,相关系数r＝0.999 3,方法检出限为0.003 4 mg/L。干扰试验表明:试样中共存元素对测定不产生干扰。将实验方法应用于5个不同锰含量水平的镍基体料炉渣中锰的测定,结果与GB 11906—1989标准方法基本一致,相对标准偏差(n=11)在0.9%～1.5%之间;对测定结果进行格拉布斯检验,结果表明11次平行的结果无异常值。方法回收率在97%～98%之间。     

Thermodynamics of inclusion formation in Fe-Ti-C-N alloys

The thermodynamics of the formation of titanium carbonitride in liquid iron-titanium-carbon-nitrogen alloys were investigated in order to predict under what conditions it will form in liquid steel. A metal-carbonitride equilibration technique was used. Titanium carbonitride of a desired composition was made by mixing and high-temperature sintering of very fine powders of titanium nitride and carbide. The formation of titanium carbonitride was confirmed by lattice parameter measurements on the samples before and after the experiments. The equilibrium concentrations of titanium, carbon, and nitrogen in equilibrium with a specific titanium carbonitride were obtained at 1873 K. Activities of titanium carbide and nitride relative to pure solid titanium carbide and nitride were calculated. It was found that titanium carbonitride solid solution is almost ideal. From the results, calculations were performed to predict at which composition various carbonitrides will form.     

Preparation of powders of titanium boronitrides in superhigh-frequency discharge plasma

Conclusions It is shown that alloys of the system titanium-boron-nitrogen can be prepared by the simultaneous reduction and nitriding of titanium and boron chlorides during their very brief residence time in a plasma type chemical reactor. The dissolution of about 6 wt.%of boron in titanium nitride lowers the temperature coefficient of electrical resistivity of titanium boronitrides by a factor of 2.5 compared with pure titanium nitride.Translated from Poroshkovaya Metallurgiya, No. 11 (131), pp. 6–9, November, 1973.     

Use of a superhigh frequency discharge for the manufacture of titanium nitride powder

Conclusions A study was made of the conditions of preparation of titanium nitride powder by the hydrogen reduction of titanium tetrachloride in a nitrogen stream heated up in a SHF discharge. The overall degree of reduction of titanium tetrachloride attains 100%. The resultant powder contains up to 98% of the nitride, ammonium chloride being one of the impurities detected in it. A characteristic property of the resultant nitride is its satisfactory low-temperature sinterability.Translated from Poroshkovaya Metallurgiya, No. 3 (111), pp. 8–11, March, 1972.     

Reaction of Titanium with Boron Nitride under Self-Propagating High-Temperature Synthesis Conditions

We have used the ASTRA computer program for thermodynamic analysis of the chemical reaction of mixtures of titanium with boron nitride in the composition range of 1-26 mass% BN under adiabatic conditions. We have calculated the adiabatic temperatures, the heat change, and the concentration of the reaction products. We have established that under self-propagating high-temperature synthesis (SHS) conditions, we can obtain alloys of titanium with titanium nitride and monoboride and alloys of titanium nitride with titanium borides. Experimental synthesis of the alloys under SHS conditions confirm the thermodynamic analysis results.     

微钛固氮降低含铌钢皮下裂纹敏感性的机理

 降低含铌低合金钢铸坯的裂纹敏感性,是实现热装热送工艺的必要条件,采用超高温激光共聚焦显微镜(HT-CLSM)、透射电镜(TEM)等手段研究了钛含量不同的含铌低合金钢(Q390、Q390GJD)高温铸坯的晶粒度及析出物特征,旨在揭示微钛固氮降低含铌钢皮下裂纹敏感性的机理。热力学计算与TEM检测结果表明,增加钢中钛质量分数(由0.010%上升到0.023%)提高了氮化钛粒子的析出温度(大于1 400 ℃),高温析出细小弥散的氮化钛粒子可钉扎奥氏体晶界,细化高温铸坯的晶粒度(由4级变成6.5级),晶粒尺寸降低了约44%,使高温铸坯的裂纹敏感性明显降低;氮化钛粒子优先析出固氮降低了铌碳氮化物、氮化铝的开始析出温度,并作为异质形核核心,抑制了铌、铝析出物在晶界析出概率,降低了析出物脆化晶界的危害。通过微钛固氮调控氮化物的析出温度、析出位置及细化晶粒的作用,有效降低了含铌钢第三脆性温度槽的宽度和深度,同时,高温抗拉强度提高了21.3%~27.5%,铸坯皮下裂纹发生率降低了80%以上。为了避免析出物的晶界链状析出导致含铌钢铸坯热装轧制裂纹,应将其钛质量分数控制在0.015%~0.020%的合理范围。     

氢化钛直接反应合成氮化钛的研究

氮化钛由于其优异特性，已在工具材料、结构材料及特殊材料中广泛应用。本文概述了用氢化钛粉在一定的低压条件下直接反应合成氮化钛的研究结果并论述了其潜在优势。     

Wear analysis of a retrieved hip implant with titanium nitride coating

There is increasing interest in using surface modification technology to improve the wear properties of titanium alloy and limit articular surface wear of metal and polyethylene components. This report details the in vivo wear performance of titanium nitride coating on a retrieved hip implant obtained postmortem from a low demand patient 1 year after total hip arthroplasty. Analysis of the well-functioning implant revealed that wear debris can originate from a titanium nitride coated femoral head, as delaminated surface asperities, and manifest as adhesive wear on the articular surface. The wear observed on this implant indicates that rigorous testing and evaluation of titanium nitride coating technology should be conducted prior to widespread use on total joint implants.     

高强度帘线钢中氮化钛夹杂的固溶行为分析

为了提高帘线钢盘条的质量,实现轧制过程高强度帘线钢中大颗粒氮化钛夹杂的有效控制,通过试验钢中氮化钛夹杂的固溶试验研究,探讨了高强度帘线钢在加热过程中氮化钛夹杂的固溶行为和影响机制。结果表明,氮化钛夹杂在加热升温阶段存在较为明显的固溶行为,且固溶效果与加热温度和保温时间密切相关。通过适当提高轧钢加热炉温度和延长保温时间以及随后的快速冷却,可以对高强度帘线钢中大颗粒氮化钛夹杂的尺寸和数量进行有效控制。     

Precipitation behavior of titanium nitride on a primary inclusion particle during solidification of bearing steel

Titanium nitride precipitation on a primary inclusion particle during solidification of bearing steel has been tracked by varying temperature in a confocal scanning violet laser microscope.Upon precipitation,an obvious growth of titanium nitride on a primary inclusion particle was observed due to the rapid solute diffusion in liquid steel.The onset of titanium nitride precipitation did not change with primary inclusion particle size,but the time of growth was greater for a smaller primary inclusion particle.Meanwhile,the particle size displayed little influence on the total precipitated amount of titanium nitride on it under the same conditions.At the later period of solidification,almost no change occurred in inclusion size,but the inclusion shape varied from circle to almost square in two-dimension,or cubic in three-dimension,to attain the equilibrium with steel.     

TiO_2对高炉渣矿相结构及冶金性能的影响

采用偏光显微镜对不同TiO_2含量(7%~16%)的高炉渣矿相结构进行系统研究。结果表明,炉渣显微结构为斑状结构、似斑状结构;斑晶矿物主要为巴依石和黄长石,基质为玻璃质、细小钛辉石、钙钛矿以及少量的金属Fe、TiC、TiN及其固溶体;随着TiO_2配加量的增大,炉渣中巴依石和钛辉石含量先降低后升高,而黄长石含量先升高后降低;当TiO_2含量超过12%以后,炉渣基质中TiC、TiN及其固溶体的含量有所增加,这些高熔点化合物会使炉渣的黏度和熔化性温度升高,导致高炉渣的流动性变差。该研究成果可为改善含钛高炉渣的流动性能提供重要的理论依据。