完全再结晶区控轧与强韧性能

本文研究了提高舞钢４２００ｍｍ轧机在奥氏体完全再结晶区压下率对产品性能的影响,结果表明,适当提高高温区的压下率,不仅提高钢板的强度韧性,而且减少了轧制首次,提高了生产率。     

酸溶硼含量对低碳钢组织性能的影响

在特定条件下定量研究了酸溶硼含量对钢材力学性能的影响。通过对比研究发现,每提高1 ppm的酸溶硼含量可以提高22.05 MPa的抗拉强度,29.55 MPa的屈服强度。酸溶硼含量的提高有效提高了钢的各项性能,钢中固溶硼对提高钢的淬透性起到至关重要的作用,改善了钢的显微组织状态,提高了钢的强度和冲击韧性,并且减少了由于BN含量的增加造成的韧性下降。     

白音诺尔铅锌矿伴生银综合回收技术研究与生产实践

针对白音诺尔铅锌矿伴生银在浮选时回收率较低的问题,研究了经济有效地提高伴生银回收率的工艺和技术,在保证铅锌回收率略有提高的情况下,最大限度地提高精铅矿中银含量,从而提高资源利用率和矿山经济效益。通过实验研究和工业试验验证,制定了白音诺尔铅锌矿伴生银综合回收的新药剂制度。与原药剂制度对比,铅锌的选矿回收率分别提高了0.43%和1.37%,有价银的回收率提高了7.35%,取得了显著的经济效益。     

优化工艺 精细操作是提高电流效率的基础

针对铝电解生产过程中电流效率难以提高其影响因素 ,对提高电流进行了探讨 ,提出了优化工艺 ,精细操作是提高电流效率的基础     

含水洗铁复合球团的生产及运用

为了改善复合球团性质及入炉性能,进行了复合球团生产工艺的调整,通过配加水洗铁,提高了复合球团的品位,同时也提高了抗低温性能,满足了冶炼生产的需要,提高了冶炼技术经济指标.     

帘线钢轧制工艺优化改进

通过提高连铸坯加热温度和轧制过程温度,优化控冷工艺,盘条的抗拉强度提高了28MPa,断面收缩率提高了3.4%,金相组织明显改善,索氏体化率提高了0.97%,氧化铁皮厚度增加了46.58%,利于机械除鳞,最终产品质量达到重点用户的要求。     

某铜铁硫矿选矿厂改扩建设计与生产实践

对某铜铁硫矿选矿厂进行改扩建设计,在原有选矿厂厂房内,通过优化工艺流程,选用相对大型的设备,将选矿厂生产能力提升至原来3倍多,获得了铜精矿品位提高1.04%,回收率提高3.26%,铁精矿品位提高1.82%,回收率提高6.72%,硫精矿品位提高2.73%,回收率提高5.19%的成果,大幅提升了企业的经济效益,并且改善了车间内操作环境。     

提高常规湿法炼锌铜直收率的实践

常规湿法炼锌工艺由于铜的浸出率较低,导致铜直收率偏低。通过采取提高液固比、提高中性浸出酸度和对中性浸出液酸化等措施,提高了铜浸出率,减少了铜的水解损失,进而提高了铜直收率。     

轧材钙处理试验

阐述了北满特钢为提高轧材探伤质量,对供轧材的钢锭进行了两轮钙处理试验,从而提高了轧材的探伤合格率,试验证明钙处理有利于提高轧材探伤合格率。     

提高烧结配料生石灰消化除尘效果的生产实践

通过对烧结配料生石灰消化除尘系统进行改造,提高了除尘效果,同时稳定了生石灰配加量和消化打水量;充分回收利用了消化蒸汽和二次扬尘,减少了资源浪费,提高了消化水温,进一步强化了生石灰消化作用,提高了混合料制粒效果和混合料料温;极大地改善了配料室工作环境,有效降低了检修劳动强度,提高了设备作业率。     

Characterisation of functionally graded and VC/steel surface alloyed composites produced using powder metallurgy

Abstract

In this study, low carbon steel specimens with surface alloyed composites were produced by means of powder metallurgy. Vanadium carbide, graphite (1·2 wt-%) and Fe were used for the surface alloyed composite, while Fe and graphite (0·2 wt-%) were used for the low carbon steel side. The powder mixtures were compacted together in the same mould. On the surface alloyed side the vanadium carbide content was changed from 5 to 25 wt-%. Microstructural investigations including EDX and X-ray, hardness measurement and abrasive wear tests were performed. The results showed that V₈C₇ formed in the alloyed surface and carbon diffusion from the alloyed surface to the parent metal created a functionally graded material. The hardness values decreased towards the parent metal. Wear resistance increased as the vanadium carbide increased in the surface alloyed composite. Thus, a functionally graded steel having a surface composite that is resistant to abrasive wear can be obtained via the powder metallurgy route.     

提高球磨机衬板耐用性的研究

高锰钢衬板初始硬度低，在球磨机的工况条件下不能充分发挥工作硬化效应。针对这种情况研制了ＺＧ６０ＭｎＣｒ３合金衬板，该衬板具有较高的初始硬度与较强的硬化能力，且耐磨性高，经工业应用表明：使用寿命比ＺＧＭｎ１３衬板提高４３．４５％。     

Investigation of modern fabricated pattern welded Damascus steel

Work on modern fabricated pattern welded Damascus steel by two of the best Russian bladesmiths was investigated. The main mechanical properties were measured, macro and microstructure were examined, and EDAX, mass-spectroscopy, and fractography tests were performed. The effect of heat treatment on both macrostructure and hardness was studied. It was shown that mechanical properties of pattern welded Damascus steel was on a level with standard tool plain carbon and low alloyed steels.     

帘线钢82B精炼过程中的酸溶铝控制

通过热力学计算和工业试验研究了影响高碳帘线钢(82B)生产过程中钢中酸溶铝含量的各种因素。为控制钢中酸溶铝含量在极低水平,首先必须使用w(Al)<0.05％的硅铁合金化;其次应该严格控制精炼温度、精炼渣的Al_2O_3含量和精炼渣碱度,以避免LF精炼过程钢液增铝。指出高碳帘线钢用VD法进行真空处理时钢液具有强烈的增铝倾向。     

Experimental and Theoretical Investigations of Hot Isostatically Pressed–Produced Stainless Steel/High Alloy Tool Steel Compound Materials

Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop–electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.     

Surface Solidification Behaviour of Micro‐Alloyed Steels under Continuous Casting Conditions

Micro‐alloyed steels are important in steel industry with regard to their unique mechanical properties. Their characterisitcs are mainly caused by the refinement of ferrite grain size by controlled precipitation of nitrides during thermomechanical treatment in hot rolling. Uncontrolled precipitations of titanium nitrides in the surface region during casting and solidification can negatively influence the surface quality of continuously cast steel, particularly when casting, thermal soaking and hot rolling are carried out in a combined process chain. Focus of this work are experimental simulations and mathematical investigations of early solidification in a CC mould, primary precipitation of nitrides, and effects of different influences such as mould contact through casting flux or direct mould contact. A laboratory rig to lead solidification on liquid casting flux was developed. The carbon content of the steel melts was varied.     

控轧控冷工艺对Nb-V钢的组织性能析出行为的影响

采用光学，电子显微技术和力学分析等方法，系统地研究了不同控轧控冷条件对铌钒复合微合金化低碳热轧钢板的组织和性能的影响规律，提出了较佳的控轧控冷工艺参数，研究结果对开发高强度船体用钢板具有参考价值。     

高速经编机粉末冶金链块

本文介绍了粉末冶金高速经编机链块的制造方法及其性能和使用情况。     

Celtic steel – an evaluation of depot finds

In the course of archaeological excavations on the Gründberg in Linz/Austria, several depots containing a total of 45 steel objects were discovered. These depots had been set up around 100 before Christ (BC). 25 objects were used to take samples for metallographic and microanalytical investigations. In the exercise of his trade, the Celtic smith could resort to different steel grades: non‐alloyed, carbon alloyed, phosphorus alloyed. The technique applied was that of fire‐forging single pieces of steel ‐ which had previously been widened by hammering – to give flat bars showing a multi‐layer structure. For workpieces with special requirements with regard both to hardness and to toughness, a number of carefully selected flat bars with differing contents of alloying metals were bonded by forge welding, which produced a compound material. Hardening by cold working as well as by torquing was already known to these Celtic craftsmen. To obtain tools with a hard edge and a tough core, cementation was used.     

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

 Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2 and 1600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.