固溶处理对铍材力学性能的影响

利用稳定低氧的气流冲击研磨铍粉，研究了固溶处理对冷、热等静压铍材和真空热压铍材力学性能的影响。结果表明，无论是热压铍材还是等静压铍材，其固溶态力学性能均比压制态低；固溶时析出的Be2SiO4导致BeO的聚集，同时，由于原料中铁含量较低，不能形成有效的固溶强化，是固溶态势压铍材力学性能降低的主要原因。     

机械合金化制取Ni—Fe—Mo粉

机械合金化可使在室温下部分互溶体系Ｎｉ－Ｆｅ－Ｍｏ形成ｆｃｃ固溶态粉末，Ｎｉ、Ｆｅ、Ｍｏ三种元素在粉末颗粒表面及内部均匀分布存在，固溶态粉末的液相生成温度约为１７１０Ｋ。     

新型钴基高温合金的组织结构与力学性能

对新设计的三种新型钴基高温合金的组织结构及性能进行了研究.结果表明：钨作为合金的主要固溶元素,其含量必须控制在17.0%～18.5%的范围内,才能有效地起到固溶强化作用.过多的钨元素将形成大量的析出相,晶粒也因此而细化,虽然合金的室温强度会有所提高,但是在1200℃高温下,变得较为薄弱的大量晶界却使强度明显降低.     

Sc含量对Al-2%Cu合金固溶处理行为的影响

借助力学性能测试及光学金相（OM）和透射电镜（TEM）的观察和分析，研究了Sc含量的变化对Al-2％Cu合金固溶处理行为和力学性能的影响。结果表明：随着Sc含量增加，合金的熔点降低；520℃／20min同溶态时，合金的拉伸强度提高（δmax达到40MPa），晶粒组织在固溶完全时仍较细小，这要归功于Sc的加入形成了细小Al3Sc粒子起到很好的作用。     

GH941新型钴基高温合金研制

本文研究了新型钴基高温合金GH941的成分、组织及性能。结果表明：钨作为合金的主要固溶元素，其含量必须控制在适当的范围内，才能有效地起到固溶强化作用，过多的钨元素将与钴、碳、铬、镍等元素形成大量的μ和M6C等析出相，使晶粒细化，在1200℃的使用温度下，大量薄弱的晶界使拉伸强度明显降低。     

稀土微合金化作用研究现状分析

分析了稀土作为微合金元素在钢中的固溶量及固溶度的测定方法,并就固溶稀土的分布和其对晶界、相变及组织的影响进行了探讨,提出了稀土在钢中微合金化的发展方向     

固溶温度对403Nb钢组织和性能的影响

研究了固溶温度（940℃-1180℃）对403Nb组织和性能的影响,结果表明：随固溶温度升高,固溶强化和回火过程合金元素碳化物析出起主要强化作用,虽然晶粒长大,但钢的强度提高;断口类型由韧性断裂转变为脆性断裂。     

机械合金化制取Ni－Fe－Mo粉

机械合金化可使在室温下部分互溶体系Ｎｉ－Ｆｅ－Ｍｏ形成ｆｃｃ固溶态粉末，Ｎｉ、Ｆｅ、Ｍｏ三种元素在粉末颗粒表面及内部均匀分布存在，固溶态粉末的液相生成温度的为１７１０Ｋ。     

内摩擦仪在球墨铸铁相变过程中对固溶碳氮的测定

笔者首次利用日本真空理工（株）产的ＩＦＴ－１５００Ｙ型横向高周波内摩擦仪测定含稀土铁素体墨铁。在不同温度热处理后，由于球状石墨的扩散改变了铁素体中的碳的含量致使材料中产生了不同固溶碳氮含量的属相。同时还借助了ＥＬ－１５００Ｙ－Ｈ型横向热膨胀仪、ＴＣ－３０００型导热系数仪及ＨＭ－１００型高温显微镜和Ｘ衍射仪对上述形成新相给予论证，尝试其多相材料固溶碳氮测定方法。     

双相不锈钢固溶处理对组织和性能的影响

双相不锈钢００Ｃｒ１８Ｎｉ５Ｍｏ３Ｓｉ２热轧钢板在９５０－１０８０℃温度范围内的固溶处理对钢的力学性能没有显著影响。随着固溶温度的提高及固熔冷速的加大，铁素体含量逐渐增加。在含ＦｅＣｌ３介质中的点蚀率（ＰＣＲ）随着固溶温度的提高而降低。     

Nb-Ti微合金钢碳氮化物的析出热力学模型及分析

以规则溶液亚点阵模型为基础,针对Fe-Nb-Ti-C-N系统,进行了热力学平衡计算。计算结果表明,高温阶段的析出相为TiN,微细的TiN强烈地抑制奥氏体晶粒长大;低温阶段的析出相以碳化物(NbTi)C为主,NbC和TiC是抑制奥氏体再结晶及再结晶后晶粒长大的主要因素。析出相形成元素Ti的增加引起其形核化学驱动力增大,并加快析出的动力学过程。     

二相粒子构成元素含量变化对Ti—IF钢平衡析出的影响

利用平衡态分析和Ｔｉ－ＩＦ钢析出物形成元素含量波动对高温二相粒子的析出规律进行了研究，得到了析出物开始析出时各个析出物形成元素含量的临界值，对ＭｎＳ析出条件有新了认识，并给出了Ｍｎ加入后所造成的各析出物元素重组关系示意图     

构造作用对内生金矿形成过程的影响

构造作用活化前成矿期含金地质体中的成矿物质,创造有利于沉析成矿的地球化学屏和赋矿空间,驱动成矿溶液从高能量区迁移到低能量区的有利部位成矿。这一过程被称为构造成矿作用。其研究有别于成矿构造或控矿构造研究。     

Surface hardening of nickel alloys by means of plasma nitriding

Surface hardening of Ni alloys by plasma nitriding was investigated by using tentative Ni binary alloys contained nitride forming elements such as Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, Mn, Fe, Al, or Si at the nitriding temperature from 673 to 1073 K. Surface hardness was different depending on the types of alloying elements, their contents, and their nitriding temperatures. Higher hardness than HV500 was obtained in Ti, V, Nb, and Cr containing alloys at 823 to 873 K, but other alloys showed lower surface hardness than HV400. The elements Ti, V, Nb, and Cr were the effective alloying elements for the surface hardening of nitrided Ni alloys. From transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis, the nitrided layer was composed of fine precipitate particles in the matrix of the nitrided layer. At the lower nitriding temperature, these particles were metastable fine particles or Ginier-Preston (GP) zone having coherency with the matrix, and these fine particles induced large microstrain in the matrix. However, at the higher nitriding temperature, equilibrium nitride particles were precipitated and coherency with the matrix was decreased. Therefore, the hardening of Ni alloys by plasma nitriding was due to the microstrain induced in the nitrided layer by the precipitation of metastable particles or GP.     

Diffusion alloying – a new manufacturing method for PM tool steels

Abstract

To increase the wear resistance of tool steels, high contents of super-hard MC type carbides formed by Ti, V or Nb are desirable. Unfortunately, these carbides precipitate primarily from the melt at high temperatures. Thus, atomising such steels is not feasible with current technology because carbides precipitating in the melt may clog the nozzle. This problem can be avoided by atomising a melt that contains high amounts of carbide forming elements but no carbon. Subsequently the powder is mixed with graphite to provide the carbon necessary to form carbides and for the hardenability of the matrix. During hipping, graphite dissolves and the carbon is distributed evenly in the material. The phase distribution of a candidate cold work tool steel consisting of a stainless steel matrix with fine, well distributed niobium carbide precipitates is reported and compared with equilibrium calculations.     

萃余液预处理方法的试验研究

萃余液预处理是避免环境污染、回收有价元素的有效途径,本次工作提出了一种新的萃余液预处理方法--氨水沉淀法,其原理是使用氨水将萃余液中和至pH≈7.5,从而使萃余液中的有价元素Zn、Cu、Pb及Fe形成氢氧化物沉淀析出,而As元素则生成FeAsO₄沉淀。固液分离后,在滤液中加入Na₂S,使其中的微量金属元素发生沉淀,最终实现萃余液中全部有价元素得到有效回收的目标,处理液可作为焙烧氰化工艺中酸浸渣氰化调浆用液。     

Effects of TiN and AlN Nanoparticles in Hot Deformation of Austenite in Steels

Recrystallisation kinetics of two low‐carbon steels, of which one with Ti and the other with Al as precipitate‐forming elements was studied by means of hot torsion tests. The mean size of TiN and AlN particles that precipitate during hot deformation was analysed by transmission electron microscopy (TEM). These results, along with the determination of the activation energy, the precipitated volume fraction and the diffusion coefficients of Ti, Al and N in austenite explain the ineffectiveness of these particles to inhibit the static recrystallisation.     

Influence of residuals on the metallurgical features of low carbon steel grades

The increased recycling of scrap leads in conventional steels to an increased content of undesirable trace elements. When scrap is used for steel production, the influence of precipitate‐forming or solid solution hardening trace elements in particular on the process and use properties has to be taken into account. The influence exerted by the elements niobium, titanium, chromium and molybdenum has been studied on the example of unalloyed deep drawing steels which are mainly used for the manufacture of automobiles. The production process – beginning with continuous casting, through hot rolling, cold rolling down to annealing – was simulated experimentally in laboratory equipment, and in parallel with a continuous casting simulator, forming dilatometer and high temperature conductimeter. Light‐optical microscopy and the EBSP measurements were used to characterise the pertaining microstructures. The mechanical final characteristics were determined in tensile tests. The results relating to continuous casting illustrate the influence of trace elements on precipitation, cracking, hot ductility and the phase transition from austenite in ferrite. The work softening during the hot rolling depends on the nature and the precipitation state of the foreign elements. The interplay of coiling temperature, precipitation and annealing temperature influences the softening during the annealing after the cold rolling. It could be shown that a large part of this takes place during the recovery. The analysed trace elements influence the final characteristics via hardening and grain sizes.     

电渣重熔H13钢中一次碳化物形成机制

 H13热作模具钢在电渣重熔过程中会在凝固末端形成粗大的碳化物及氮化物,由于生成温度高,热稳定性好,会保留到最终热处理状态,对钢材的性能产生严重影响。应用偏析模型计算并说明了凝固过程生成粗大的共晶碳化物和氮化物的可能,当固相率达到0.82时由残余液相生成TiN,随着温度进一步下降在接近凝固终点时生成VC0.88,由于碳化物中固溶了其他合金元素,认为生成的VC0.88的活度不为1,试验检测的碳化物合金元素含量与理论假设基本吻合。对粗大的碳氮化物的特点及细化减少碳化物进行简单讨论。     

Endodontic treatment in three cases of dens invaginatus

Surface analysis of similar titanium screw implants from four manufacturers (Br?nemark System, 3i, Impla-Med and Restore) showed considerable differences in the composition of the surface oxides. Br?nemark System implants had a markedly higher surface content of the natural oxide forming elements: titanium and oxygen. These implants also had a lower content of all contaminants (except boron) and significantly less variation in composition between different samples and points of analyses.