纯净钢的开发与生产

对纯净钢的生产工艺和技术进行了简述,结合济钢三炼钢和中厚板的生产实际,提出了改进连铸坯内部质量的措施,为进一步开发生产高附加值、高难度和高技术含量的纯净钢提供了依据.     

应用EAF-LF-VD工艺路线生产纯净钢的过程控制技术

概要论述了EAF-LF-VD工艺路线下,纯净钢生产的过程控制和基本技术要点。钢中[P]、[S]、[O]的控制应抓住EAF炉、LF炉温度条件、熔池条件,选择合理的脱氧制度、吹Ar模式、渣系组成,强化造渣与传质,其含量可控制在工艺设定值以内。钢中[H]、[N]的控制重点在VD炉操作和工作参数控制。钢中夹杂物的控制贯穿初炼-精炼-脱气过程,使得钢中的T[O]不断降低,经过变性、聚集、上浮、渣系吸附,净化钢水。     

南钢钢液钙处理的研究

通过热力学计算,分析残钙量对铝镇静钢中夹杂物钙处理变性的影响.理论分析表明,T=1873 K,酸溶铝质量分数为0.02%～0.05%时,残钙质量分数应大于18×10-6,最好控制在31 × 10-6之上.现场试验结果表明,吨钢钙加入量为149.1～171.5 g时,随加钙量的增加,钙收得率增加,残钙量增加,夹杂物变性效...     

RH前后钙处理对高钛高强钢夹杂物的影响

针对在"LF→RH→钙处理"路径生产高钛钢时存在钛含量控制不稳定的问题,本文开展将钙处理调整至LF结束RH前的试验,并与原工艺进行对比以考察夹杂物的变化。结果表明:1)RH前喂钙线炉次的钛损平均比RH后喂钙线炉次的少0.0041%;2)RH前喂钙线的夹杂物数量和尺寸都小于RH破空后喂线,且夹杂物的类型更接近于钙铝酸盐,对热轧高强钢成品的力学性能和冲击功影响不大。     

钙处理对LG510钢夹杂物的影响及热力学分析

在热力学计算的基础上,对某厂钙处理前后的汽车大梁钢LG510进行取样研究,探讨钙处理对汽车大梁钢LG510夹杂物的影响.结果表明,钙处理后钢中Al2O3 夹杂物得到有效变性,夹杂物的数量明显减少,夹杂物尺寸也明显减小,夹杂物形状更加规则;钢液相线温度为1873K、钢中ω[Al]为0.028%时,钢中ω[O]、ω[Ca]分别控制在2.8×10^-6-11.5×10^-6、0.14×10^-6-7×10^-6范围内,Al2O3 夹杂变性效果良好;同时将钢中ω[S]控制在0.011% 以下,既可生成液态铝酸钙夹杂物,也可减少CaS夹杂生成.     

钙镁除铋机理的热力学分析

将配料时各物质的初始浓度积和实验终了时的浓度积与其它研究者得出的分式计算的各种物质和溶度积进行比较，论证了钙、镁除铋的机理，并对各研究者所得出的溶度积之间的偏差作出了分析。     

双波长吸光光度法同时测定水中的钙和镁

叙述了以酸性铬蓝Ｋ（ＡＣＢＫ）为显色剂,采用双波长光谍法对钙,镁的同时测定。应用该方法可消除钙,镁的相互干扰,无需分离和加掩蔽剂。     

火焰喷焊铁基和镍基合金层的组织与性能

对16Mn钢表面氧乙炔火焰喷焊自熔性铁基及镍基合金粉末得到铁基合金喷焊层和镍基合金喷焊层，并对两种喷焊层进行了显微组织，组成相，硬度和耐磨性以及抗热疲劳性能的比较研究，结果表明，两种堆焊层组织都具有枝晶生长特征，枝晶间存在着共晶组织，两种涂层均由γ固溶体和多种共晶化合物相组成，但镍基合金喷焊层的枝晶比较细小，镍基合金喷焊层比较基合金喷焊层具有较高的硬度和耐磨性，同时也具有较好的抗热疲劳性能。     

W对Co基合金熔覆层组织和耐锌蚀性能的影响

为了提高热镀锌生产线关键部件的使用寿命并节约热镀锌成本,采用半导体激光器在316L不锈钢表面制备了具有不同成分的两种钴基合金熔覆层.分别对激光熔覆层的组织形貌、成分、相结构、显微硬度及耐锌蚀性能进行了研究.结果表明,W元素的加入使得熔覆层晶粒发生细化,熔覆层组织主要由γ-Co固溶体、Co_3Mo_2Si相和少量Cr_7C_3相组成,同时还生成了少量弥散分布的Co_6W_6C相.添加W元素后熔覆层的平均硬度可达986 HV,相比未添加W元素的Co基合金熔覆层约增加了114 HV,且约为316L不锈钢的4.5倍.与原Co基合金熔覆层相比,添加了W元素的Co基合金熔覆层中弥散分布的Co_6W_6C相使熔覆层耐锌蚀性能大幅度提高.     

稀土镁复合处理对X70管线钢组织和性能的影响

采用金相观察、硬度测试、力学性能测试等方法,研究了稀土镁处理对X70管线钢组织与性能的影响.结果表明,微量稀土镁可显著减小晶粒尺寸,提高X70管线钢室温和高温的力学性能;但随温度升高稀土镁对材料的高温力学性能影响会逐步减小.     

Strengthening mechanism of steels treated by barium-bearing alloys

The deoxidation,desuifurization,dephosphorization,microstructure,and mechanical properties of steels treated by bar- ium-bearing alloys were investigated in laboratory and by industrial tests.The results show that barium takes part in the deoxidation reaction at the beginning of the experiments,generating oxide and sulfide compound inclusions,which easily float up from the mol- ten steel,leading to the rapid reduction of total oxygen content to a very low level.The desulfurization and dephosphorization capa- bilities of calcium-bearing alloys increase with the addition of barium.The results of OM and SEM observations and mechanical property tests show that the structure of the steel treated by barium-bearing alloys is refined remarkably,the lamellar thickness of pearlitic structure decreases,and the pearlitic morphology shows clustering distribution.Less barium exists in steel substrate and the enrichment of barium-bearing precipitated phase mostly occurs in grain boundary and phase boundary,which can prevent the move- ment of grain boundary and dislocation during the heat treatment and the deformation processes.Therefore,the strength and tough- ness of barium-treated steels are improved by the effect of grain-boundary strengthening and nail-prick dislocation.     

Ti-Cu-Ni-Zr块体非晶合金形成能力及其压缩性能

采用铜模铸造法制备了不同直径的Ti40Cu34+xNi16-xZr10(x=0,2,4,5,6)系列合金,并利用X射线衍射(XRD)、扫描电镜(SEM)、差氏扫描量热仪(DSC)研究了合金的相结构、显微组织、热稳定性.结果表明:只有Ti40Cu39Ni11Zr10合金成分可制备出2 mm的全非晶结构,增加制备尺寸到3 mm、4 mm后,有TiCu晶体相析出;玻璃转变温度Tg、晶化温度Tx分别为665 K和712 K,过冷液相区ΔTx为47K.压缩实验表明:Ti40Cu39Ni11Zr10块体非晶合金具有高达1 931 MPa的屈服强度,并伴有0.3%左右微量压缩变形量,塑性变形以锯齿形式出现;Ti40Cu34Ni16Zr10合金具有1.3%的压缩变形量,TiCu相的析出提高了该合金压缩变形量.     

铸造锌铝合金的一次结晶和组织特点

本文采用液淬—微分热分析试验装置、差热分析仪及扫描电镜等对铸造锌铝合金的一次结晶和组织特点进行了研究。试验结果表明:在Zn—Al二元合金相图中确有包晶反应,β相是共晶转变的领先相,共晶团呈辐射状生长。由于不平衡结晶,在亚共晶合金中出现过共晶的初生β相;而在过共晶合金中出现亚共晶的初生η相。另外,含高铝的锌基合金在晶界处产生网状共晶体,在Zn—27Al合金中加入2.5％Cu,组织内出现富铜相ε。     

Microstructure and magnetostrictive performance of NbC-doped<100>oriented Fe-Ga alloys

The<100>oriented Fe83Ga17 alloy rods with various NbC contents less than 1at%were prepared by the directional solidification method at a growth rate of 720 mm?h?1. Low NbC-content was found to affect t...     

Structure and flaws of CuCr alloys by explosive compaction

CuCr alloys are prepared by mechanical alloying and explosive compaction. After we have studied their structure and flaws, the results show that the CuCr alloys have definite strength and toughness, while their fractured surface displays ductile characteristics. In the metallurgical structure, CuCr alloys are composed of two phases of uniform distribution; the SEM morphology is like thin strips with an end arrangement that is bonded to each other and the two-phase distribution of CuCr alloys is more homogenous. It is in only in a very small zone that formation of Cu-rich and Cr-rich phases take place. The flaws of the compaction samples are mainly central-holes and cracks.     

Grain Refining Performance of SHS Al—50TiC Master Alloys for Commercially pure Aluminum

An Al-50wt^TiC composite was directly synthesized by self-propagating high-temperature synthesis(SHS) technology,and then was used as a grain refining master alloy for commercially pure aluminun.The microstructure and grain refining performance of the synthesized master alloy were emphatically investigated.The SHS master alloy only ocntained submicron TiC particles except for Al matrix.Moreover,TiC particles were relatively free of agglomeration.Grain refining tests show that adding only 0.1wt^ of the master alloys to the aluminum melt could transform the sturcture of the solidified samples from coarse columnar grains to fine almost 1.5h at 1003K.Therefore,it is concluded that the SHS master alloy is an effective grain refiner for aluminum and its alloys,and that it is highly resistant to the grain refining fading encountered with most grain refiners.     

水泥砂浆外涂有机硅烷防护效果研究

为了研究外涂有机硅水泥砂浆材料的防护效果,用有机硅涂料对水泥砂浆进行表面涂层处理,并与未涂层水泥砂浆和涂丙烯酸的水泥砂浆相比较,系统研究了改性有机硅涂层对防水抗渗性能、抗碳化性能、抗氯离子渗透等性能的影响。试验结果表明：有机硅外涂水泥砂浆呈现出较好地疏水效果,使用有机硅外涂水泥砂浆的防水抗渗性能大大改善了;与空白组、丙烯酸组相比,涂有有机硅涂层的砂浆的氯离子扩散系数显著降低,约为空白组的1／4,约为丙烯酸组的1／3;随着养护时间的增加,涂有有机硅涂层的试块的碳化程度明显低于空白组和丙烯酸组,而且碳化深度增长速度明显变慢;空白样水泥砂浆密实性较差,表面粗糙多孔,试块结构疏松,而加了硅烷的试块涂料与水泥浆表面粘结紧密,界面区并不明显。为烷氧基有机硅烷作为水泥砂浆防护材料实际工程应用奠定一定的基础。     

铝合金旋转喷吹净化工艺的研究

从表征流态的物理量出发，通过计算建立了铝合金旋转喷吹除气系统的物理模型，以CO2-NaOH体系来模拟实际的铝液净化，用CO2通入溶液后引起的pH的变化来模拟铝液中含氢量的变化．研究了影响铝合金旋转喷吹净化的因素，结果表明转子转速对净化效果影响最大，气流量次之．通过模拟实验获得最佳工艺参数及工艺参数的选取原则，并通过传统的C2Cl6的净化工艺和旋转喷吹净化工艺的比较中证实了旋转喷吹净化工艺优异的除氢效果．     

氧化物弥散强化合金的再结晶行为及强化机理的研究

运用光学显微镜测量了ODS(Oxide Dispersion Strenghtened)合金的晶界迁移速度,并计算了再结晶激活能.再结晶温度测量结果表明,PM2000的再结晶温度为720 ℃,与传统金属材料的再结晶温度(0.4～0.6 Tm)的规律一致.TEM分析显示,再结晶后的晶粒呈高长径比的柱状晶,再结晶过程中晶界前沿受到颗粒的钉扎.ODS合金基体中的位错被颗粒钉扎在脱钉侧,表现出相互吸引的作用方式,因而认为颗粒/位错相互吸引机理是ODS合金强化的原因.