Preparation of special silicon steel grade MgO from hydromagnesite

A preparation technology of MgO powder used in special silicon steel from hydromagnesite mineral has been developed. The preparation technology includes the following steps： （1） calcining the hydromagnesite at 700-750°C for 1.5-2 h; （2） hydrating the calcined hydromagnesite to be slurry containing the solid-liquid ratio of 15-20 g？L？1; （3） acquiring Mg（HCO3）2 solution by carbonating the slurry, the carbonation temperature, CO2 pressure, and end point PH value of carbonation are less than 40°C, 0.4-0.6 MPa, and 7 respectively during the carbonation process; （4） preparing precipitated basic magnesium carbonate by thermally decomposing the Mg（HCO3）2 solution at 90-100°C; （5） obtaining the MgO product by calcining the precipitated basic magnesium carbonate at 850-950°C for 30-60 min, and adopting flowing nitrogen during the cooling process. By using this technology, more than 80wt% magnesium in hydromagnesite mineral can be extracted, and high-performance MgO products used in special silicon steel can be ob- tained.

Technology innovations on high quality special steel products

Because special steels are the basic materials for industrialization,a national R&D program on special steel technology for high quality products have been granted to promote the special steel production and applications since 2008.Since then,great progresses have been achieved on ferritic stainless steel sheets,heat resistance steel pipes and tubes,microalloyed forging steel bars,and mould steel forgings for hot working. The ratio of ferritic stainless steel sheets produced by TISCO and Baosteel has been promoted through technology innovations and increased 42%and 48 in 2009 respectively.439M steel sheets have been used to exhaust system,and 444 steel sheets have been applied to kitchen and architecture.The production technologies for heat resistance steel pipes and tubes(T/P92,S3043,S31042 steels) have been developed in Baosteel and Pansteel to meet the market requirements.Meanwhile,the round bloom technology has been initiated in Xingcheng Steel.The new technologies for microalloyed forging steels,low cost steel bar,and tailored steel and components,were proposed by CISRI based on the understanding of precise chemical composition and segregation control.And the applications of microalloyed forging steel bars have been promoted remarkably.The researchers have developed high quality mould steel technologies,heavy section forgings of 718 steel,high premium H13 steel blocks and large diameter mandrels used for seamless pipe rolling.The technology innovations of the program could lead to the progress of production technology in special steel sheets,pipes,bars and forgings,and meet the demands from market.For the moment,it is actually believed that there still strong requirements for the technology innovations on special steels.

The development of China's special steel and the application prospects of spray-formed materials

Suggestions have been put forward speeding up the development of high-level tool steel and mold steel in China based on the analysis of products and development status of special steel home and abroad. Feasibility and necessity to produce high-level tool steel and mold steel by applying the spray forming method in future have been put forward.

Development of ultra high strength special steels and wrought nickel base superalloys

Ultra-high strength special steels and wrought Ni-base superalloys are been ever increasingly applied in aircraft and aerospace,power generation,oil-gas and other industries.The development of those materials is driven by tougher working conditions,higher efficiency,environment consideration,resource limitation and cost reduction. This presentation will focus on the development of ultra high strength special steels and wrought Ni-base superalloys in aircraft industry. The examples of ultra-high strength steels include: (1) Ultra-high strength stainless steels for landing gear and other structures; (2)High speed and high temperature main shaft bearing steels; (3) Ultra-high strength steels for jet engine main shaft. New and modified Ni-base superalloys will be discussed by examples of (1 )Low cost,process-friendly superalloys with higher performance; (2)Modification of hard-to-processed superalloys. Future development of those materials will be addressed.

Study on the properties and application of the steel slag special fine aggregate

The physical properties, grading stability and application stability of the steel slag special fine aggregate （diameter≤0. 8mm） at Baosteel were analyzed in this study, and the mechanical and working properties were studied when the aggregate was applied to concrete. The： result shows that the aggregate has special advantages of hardness and wear-resistance, so it can be used as an excellent road surface material. The concrete mixed with the steel slag special fine aggregate exhibits good mechanical properties and working properties,which is safe and reliable.

Classification of steel based on laser-induced breakdown spectroscopy combined with restricted Boltzmann machine and support vector machine

In recent years,a laser-induced breakdown spectrometer(LIBS)combined with machine learning has been widely developed for steel classification.However,the much redundant information of LIBS spectra increases the computation complexity for classification.In this work,restricted Boltzmann machines(RBM)and principal component analysis(PCA)were used for dimension reduction of datasets,respectively.Then,a support vector machine(SVM)was adopted to process feature information.Two models(RBM-SVM and PCA-SVM)are compared in terms of performance.After optimization,the accuracy of the RBM-SVM model can achieve 100%,and the maximum dimension reduction time is 33.18 s,which is nearly half of that of the PCA model(53.19 s).These results preliminarily indicate that LIBS combined with RBM-SVM has great potential in the real-time classification of steel.

Baosteel's progressive advance in manufacturing high performance alloys

Backed by over 50 years time-tested experience in alloys manufacturing,Baosteel Special Steels play the leading role in the development and production of high performance alloys in China.The key alloys we produce for the domestic and foreign top-end market cover the Ti-alloys,and structural steels.The alloy melting processes include VIM,VAR,ESR,EB &PAM,EAF,AOD,VOD,LF,VD and the casting processes include IC,CC.The metal forming processes involve forging & isothermal forging,hot &cold rolling,extruding,drawing,and sheet metal operations.The production capability has been further strengthened by our unparalleled production lines and state-of-the-art facilities, comprehensive product analysis,superior quality assurance to national and international standards and all-round customer service.

特殊钢棒线材工艺技术发展现状

高速无扭轧机以及无头轧制技术、精密轧机技术、低温轧制技术、控冷技术等的持续进步为提高棒线材产量、钢材收得率、降低能耗等提供了工艺装备和技术保证。介绍了国内外棒材生产厂普遍采用的先进工艺装备技术,包括No-Twist^(?)高速无扭轧机,Stelmor^(?)冷却技术以及RSM^(?)、TMB^(?)、RSB^(?)精密轧机等。

新标准 新材质(下)

文章论述优质合金模具钢新标准的颁发必要性及迫切性,新标准的技术指标,先进之处及执行新标准的工艺要素。执行新标准的同时,必须重视钢材表面质量,重视钢厂与客户之间的供需关系、重视市场需求的性能更优的特色模具钢的技术开发。

钛、镍特种金属板带工程六辊轧机的配置优化

针对国内、国际的特殊钢市场,宝钢股份特殊钢分公司钛、镍特种金属板带工程主要生产高、精、尖的特殊钢板带产品。根据此工程冷轧产品的特性,本文详细探讨了采用的六辊粗轧机的选型、配置及优化。

西宁特钢小棒材连轧生产线工艺特点

介绍了西宁特殊钢股份有限公司在建小棒材生产线的产品、工艺和设备特点。该生产线采用全数字步进梁式加热炉、PSM三辊减定径机、热机轧制等先进技术,将对提高产品质量、降低生产成本、提高市场竞争力发挥积极作用。

Study on formation of non-metallic inclusions with lower melting temperatures in extra low oxygen special steels

Investigations were made both in laboratorial and industrial scales on formation of non-metallic inclusions with relatively lower melting temperatures to improve the fatigue property of the special steels which contained extra low oxygen.It was found in laboratory studies that steel/slag reaction time largely affected non-metallic inclusions in steel.With the slag/steel reaction time increasing from 30 to 90 min,inclusions of MgO-Al2O3 spinel were gradually changed into CaO-MgO-Al2O3 system inclusions which were surrounded by lower melting temperature softer CaO-Al2O3 surface layers.By using high basicity and as much as 41 mass% Al2O3 refining slag,the ratio of the lower melting temperature CaO-MgO-Al2O3 system inclusions was remarkably increased to above 80%.In the industrial experiments,it was found that the inclusions changed in the order of "Al2O3 →MgO-Al2O3 system→CaO-MgO-Al2O3 system" in the secondary refining,and the change from MgO-Al2O3 system to CaO-MgO-Al2O3 system took place from the outside to the inside.The diffusion of CaO and MgO inside the layer of CaO-MgO-Al2O3 was considered as the controlling step of the inclusion transfer.Through LF and RH refining,most inclusions could be transferred to lower melting temperature CaO-Al2O3 and CaO-MgO-Al2O3 system inclusions.

攀长钢特殊钢棒线材连轧生产线工艺设备特点

介绍了具有国际先进水平的攀长钢特殊钢棒线材连轧生产线产品品种规格、车间布置、工艺设备特点,以及步进梁式加热炉、轧机、减定径机、飞剪、吐丝机等主要设备技术参数。

Effect of CaF2 content in refining slag on formation behavior of spinel inclusion in Ni-Cr-V-alloyed special steel

The influence of CaF2 content on the formation behavior of spinel inclusions in the Ni-Cr-V-alloyed special steel was presented. The spinel was not formed at CaF2 content lower than 10 wt%. However, it was formed at early stage when the CaF2 content was greater than 30 wt%, followed by a modification to the aluminosilicate-type inclusions. Because the slag was saturated by MgO, the activity of MgO was unity irrespective of CaF2 content in the slag. Thus, Mg was transferred from slag to metal phase. Mg transferred to molten steel reacted with Al2O3-rich inclusions to form MgO.Al2O3 spinel. However, the spinel inclusion was modified to aluminosilicate-type inclusions by the reaction with Si and Ca transferred from slag to molten steel about 2-3 h later.

开坯轧制技术在特殊钢生产线上的应用

介绍了国内某特殊钢厂椎1350开坯轧机改造工程的基本概况、装备改造前后水平对比、设计主要亮点。轧机机组由椎850增大到椎1350,单道次压下量得到了提高,产品组织性能显著改善。改造后的开坯机组自动化水平大大提高,可实现全自动轧钢。

The research and development of new type of ferro-base heat-resistant alloy

Nickel-base superalloys are high performance materials subject to severe operating conditions in the high temperature turbine section of gas turbine engines.Turbine blades in modern engines are fabricated from Ni-base alloy single crystals which are strengthened by ordered g' precipitates.Turbine disks are made from polycrystal line Ni-base alloys because these components have higher strength requirements(due to higher stresses).By increasing the upper temperature limit for the next generation of disk materials,the aviation industry will see significant environmental as well as cost benefits. Researchers in the High Temperature Materials Center of the National Institute of Materials Science of Japan have recently completed their work on a new kind of disk alloys.The new disk alloys,a kind of nickel-coble-base superalloys processed by a normal cast and wrought(C & W) route,can withstand temperatures in excess of 725 degree centigrade,a 50-degree increase over C&W disks currently in operation. In this presentation,the author shows the design idea,workability and properties of these Ni-Co-base superalloys. Furthermore,the evaluation of the processing and microstructure on a full-scale processing of Ni-Co-base superalloy turbine disk are described,which demonstrated the advantages and possibility of the Ni-Co-base disc alloys at the component level.

A Project of Anhui Shengshi New-energy Co.,Ltd.Put into Production

On July II, 2013, a project ofAnhui Shengshi New- energy Materials and Technology Co., Ltd. was put into production with an annual capacity of 40 thousand tons quartz glass, which was the largest quartz glass production line in the world. The total investment of theproject was CNY 110 million. The new process can save energy over 30% than the traditional one. The project with an annual sales income of CNY 165 million can change the short supply of architectural crystal glass and high-grade ware glass in China＇s market.

超高速度生产优质线材的TMB(先进技术

在生产特殊钢线材轧机上应用达涅利摩加沙玛公司的一项新技术,即双模块机组(TMB),生产能力平均提高10%,最终产品具有更好的技术性能。

Preface for Special Column on Automotive Steel

It is believed that steels are still the most important materials for automobile in the foreseeable future because of the advantages in performance, cost, tolerance, fabrication, and recycling, etc. Over decades, a variety of steels are developed and widely used in the car body, from low carbon steel to IF steel, BH steel,

特种钢冷轧主轧机变频异步电动机的设计

特种钢冷轧主轧机项目5台主轧异步电动机采用同一规格电机设计,此研究的成功,代表了变频调速领域技术向前迈进了坚实的一步。对持续稳定的开拓发展冷轧变频异步电机市场提供了有力保障。