4-(2-噻唑偶氮)间苯二酚分光光度法测定钢中微量铬

用4-(2-噻唑偶氮)间苯二酚(TAR)光度法测定钢中微量铬已有报道,但需经萃取分离,操作较繁。本文研究了在乳化剂OP和十二烷基磺酸钠(SDS)存在下铬与TAR的显色条件,并拟定了测定钢中微量铬的新方法。此法经沉淀分离消除了干扰离子的影响,用于钢中微量铬的测定结果满意。     

铬微合金化高碳重载车轮钢的连续冷却

 采用Gleeble 3500模拟试验机、金相显微镜和扫描电镜研究了两种含铬微合金高碳重载车轮钢的连续冷却组织转变规律,分析了冷速对组织及性能的影响。试验结果表明,铬元素含量高的高碳重载车轮钢的临界冷却速度低,淬透性高,珠光体域和珠光体片层间距小,洛氏硬度高;冷速为5.0、80、10.0℃/s时有少量的贝氏体和针状铁素体出现,且它们的体积分数随铬含量的增加而增加。     

车轮钢AG400CL的研制与开发

采用低碳低硅的成分体系,在1780mm热连轧生产线上开发出了车轮钢AG400CL.并进行了卷取温度对车轮钢性能影响的试验,结果表明:卷取温度从600℃降到560℃,对车轮钢的强度和韧性影响较小.     

铬蓝黑R分光光度法测定钢中微量铬

研究了铬蓝黑Ｒ分光光度法测定钢中微量铬的方法。在ＨＡｃ－ＮａＡｃ弱酸性介质中,铬与铬蓝黑Ｒ形成蓝色络合物,最大吸收波长位于６００ｎｍ处,表现摩尔吸光系数ε＝２．１９×１０４,铬含量在０～６０μｇ／５０ｍｌ范围内符合比尔定律。方法用于钢中微量铬的测定,结果满意。     

滚形车轮用钢板的试制

1车轮用钢的技术条件及化学成分 车轮钢在具有强度、成形、焊接和疲劳等优良的综合机械性能的基础上,还要具有良好的表面质量和严格的厚度公差,以及良好的延伸凸缘性能.其主要技术条件见表1.车轮钢的化学成分要求比较严格(表2).     

恒电流库仑滴定法测定钢中微量铬和锰

恒电流库仑滴定法测定钢中微量铬和锰郑礼胜,王士龙（山东建材学院应用化学系,济南,２５００２２）在钢铁分析中,钢中微量铬、锰的测定通常采用分光光度法。由于恒电流库仑滴定具有较高的灵敏度和准确度,而且比容量分析更易自动化,也无需配制标准溶液,因此特别适用...     

热轧双相钢的合金设计

本文讨论了热轧双相钢的合金设计问题,研究了热轧双相钢的成分、生产工艺与组织、性能之间的关系,试验结果表明,锰-硅-铬是热轧双相钢的基本合金系,为进一步改善生产工艺性,可添加少量的钼或微量硼、镓。     

车轮用钢断裂力学性能研究

对国产Ｒ７、Ｒ８和ＧＬ６０辗钢车轮，巴西辗钢车轮及美国Ａｂｅｘ公司和Ｇｒｉｆｆｉｎ公司的铸钢车轮用钢的断裂力学性能进行了对比研究。结果表明，国产车轮钢疲劳裂纹萌生抗力高于国外车轮钢，Ｒ７钢裂纹萌生抗力最高，六种车轮钢的疲劳门槛值相当，稳态阶段的疲劳裂纹扩展速率也相差不大，国产车轮和巴西车轮钢断裂韧性Ｋｏ值较Ａｂｅｘ和Ｇｒｉｆｆｉｎ车轮钢大。结合断口作了初步分析。     

钒、铬微合金化地铁车轮用ER7钢的生产实践

通过对地铁用车轮用钢ER7的生产工艺、产品性能等进行研究,采用"转炉-LF炉-VD炉-圆坯连铸"生产工艺路线,采取钒、铬微合金化,同时对钙处理方式及硫线加入时机进行优化,控制钢水过热度,调整二冷水量及末端搅拌参数,使铸坯的碳偏析、中心疏松及缩孔得到有效控制,产品性能完全满足地铁车轮对强度、韧性、塑性及抗疲劳性能的要求。     

轿车车轮用钢的研制

本文介绍了宝钢研制成功的轿车滚形车轮用钢的技术条件、钢的化学成份、生产工艺和钢板的性能。宝钢的车轮钢尺寸精度高,成形性能好,机械性能稳定。用细化晶粒的方法有效地提高了钢板的疲劳性能,使车轮实体的疲劳寿命达到了装车要求。     

Fatigue Property of Low Cost and High Strength Wheel Steel for Commercial Vehicle

 The fatigue properties of the newly developed wheel steel used for commercial vehicles were studied using push pull axial loading fatigue tests with stress ratio R=-1. Q235B steel, which is conventionally applied to commercial vehicle wheels, was also analyzed for comparison. Although the chemical composition and microstructure (ferrite and pearlite) of newly developed wheel steel were similar to those of Q235B, the 107 cycles fatigue limit of the new wheel steel was 260 MPa, which is 24% higher than that of Q235B (210 MPa). The improvement of the fatigue strength of the new wheel steel can be attributed to grain refinement. In order to investigate the effect of the decrease in thickness of the wheel steel on the fatigue property of the wheel, dynamic cornering fatigue tests were conducted on full scale wheels with the model of 825×225. The results indicated that the newly developed wheel steel had outstanding fatigue life even if the mass loss was 10% in comparison with Q235B.     

Research of DP600 high strength steel wheels

Steel has been used as a traditional wheel materials for a long time.Before 1980’ s,over 90% wheels were made of steels.Then,the yield strength of wheel steels increased gradually from 240 -350 MPa to 600 MPa or higher.The advanced high strength steels become the main wheel materials.Since 1990’s,DP600 has been broadly applied in steel wheels oversea.However,there was little research of application of high strength steel wheels(especially wheel disc) in domestic wheel industrial.In presence, DP600 steel wheel is only developed in FAWSH by using imported CKD.Other domestic steel wheel manufacturers did little work on high strength DP600 wheel discs.Baosteel wheels Co.Ltd.is the first domestic company producing DP600 steel discs and has become the leading company in production of high strength wheel.Because of the high strength of DP600,its formability,springback,and wrinkle have become the keys of the successful application of DP600 steel.In this paper,the metallurgical and mechanical properties are firstly introduced and formation problems of DP600 are described compared to traditional steels.Secondly,FLD analysis has been done.Wrinkle and more springback are recognized.To solve these problems,an optimized solution is designed and the good result is obtained.The test has shown that the fatigue property of steel wheel discs made by DP600 have been greatly improved.     

不同加热温度下钒对车轮钢强韧性的影响

研究了不同正火加热温度下钒对车轮钢强韧性的影响.结果表明,当加热温度较低时,在强度与无V钢相同的情况下,加钒可显著提高车轮钢的低温冲击韧性;当加热温度较高时,在韧性与无V钢相同的情况下,加钒可显著提高车轮钢的强度.含V车轮钢存在一个适中的加热温度,可获得较好的强韧性匹配.含V车轮钢力学性能的变化规律与V(C,N)的溶解与析出行为有关.     

Prospects of the application of barium-bearing master alloys for the deoxidation and modification of a railroad metal

The prospects of using barium-bearing master alloys for the deoxidation and modification of wheel steel are considered. The oxygen solubility is thermodynamically calculated in carbon-containing wheel steel melts for various deoxidation versions, and the results of laboratory and industrial experiments on the deoxidation and modification of railroad wheel steel are discussed. Industrial experiments performed at OAO Vyksunsk Metallurgical Works show that the use of barium-bearing master alloys for the deoxidation and modification of wheel steel under mass production conditions leads to a decrease in the nonmetallic inclusion contamination of a metal, a decrease in the rejection of solid-rolled railroad wheels, grain refinement in a metal, and an increase in its mechanical properties.     

车轮钢摩擦热影响区的相变及其损伤机理

将有限元热力耦合一温度场分析与材料相变特征的实验研究相结合，研究了高速度(200kin／h)、大载荷(10^5N)条件下车轮摩擦热影响区的相变过程，探讨了材料对该过程的影响。结果表明，轮一轨摩擦导致的车轮踏面局部升温可超过材料的奥氏体相变的临界点，碳含量为0．5％时，完全奥氏体化层的深度可达0．6mm；过冷奥氏体高速冷却，几乎全部形成脆硬的马氏体薄层，造成踏面剥离。通过降碳来降低车轮钢奥氏体相变的临界点，可以显著抑制踏面马氏体层的形成。随着碳含量从0．7％降至0．4％，材料的Ae3提高45℃，马氏体层的厚度减小30％，有助于减少车轮踏面的热疲劳损伤。     

车轮钢钢包精炼过程中氮含量变化规律

由于气体氮对车轮韧性有明显的影响,因而掌握钢中氮含量变化规律对于改善车轮性能具有实际意义。对车轮钢精炼过程氮含量变化及影响规律进行了较全面的分析。     

快速车轮钢的质量控制

为了提高车轮钢质量,满足高速铁路对车轮的需要,对马钢生产的快速车轮钢的化学成分、气体含量、非金属夹杂和力学性能作了统计分析。介绍了目前快速车钢的实物质量,提出了车轮钢冶炼工艺的新发展。     

铁路重载货车车轮新材料的研制

针对重载车轮的损伤特点,研制了一种以C、Si为主要强化元素的铁素体-珠光体型车轮新材料,通过C、Si含量的合理配合,使车轮材料具备了高强度并保持了较高的韧性,同时具有合理的相变特性.装车运行试验表明,与目前常用的车轮材料相比,这种车轮材料的抗机械损伤性能和抗热损伤性能得到了较好的协调,更适合重载运输条件.     

车轮钢氮控制工艺的优化

对河北钢铁集团邯钢公司邯宝炼钢厂车轮钢的生产过程进行跟踪,全过程研究了"LD→LF→CC"工艺生产车轮钢各工序氮含量的变化。通过优化控制工艺,推行全程控氮,使车轮钢成品w(N)稳定在45.00×10-6以内,平均为31.61×10-6,提高了车轮钢的质量。     

Experimental and Numerical Investigation of the Thermal Effects on Railway Wheels for Shoe-Braked High-Speed Train Applications

An improved railway wheel steel containing higher contents of C, Mn, Si, and V than the traditional ER7 steel was developed by alloy design for shoe-braked high-speed train applications. The effects of the thermal load on the microstructure and mechanical properties of a wheel made from this steel were investigated using a combined experimental and numerical approach. The wheel braking was studied using finite element simulations that account for the thermal loading of the wheel in order to find the temperatures reached in the wheel rim. Hardness measurements, tensile tests, toughness tests, fatigue crack growth tests, and microstructural observations were carried out on samples extracted from real wheels, with and without heat treatments simulating the modification of the microstructure due to the shoe braking. The results on the un-treated samples showed that the improved steel has a better combination of strength and toughness than ER7 steel. The results on the heat-treated samples showed that the improved steel maintains acceptable mechanical properties provided the maximum temperature during braking is below the A₃ temperature of the steel (around 790 °C).