Table of Content

05 August 2007, Volume 23 Issue 04

Previous Issue    Next Issue

专题论述

Recent Progress in Oxide Metallurgy Technology and its Application

LIU Zhong-zhu;Mamoru KUWABARA

2007, 23(04):  1-6.  doi:

Asbtract ( 3254 )  

Related Articles | Metrics

The background of the proposition and development of Oxide Metallurgy Technology has been reviewed. The main concepts of that technology and its effects on the microstructure and performances of steel have been introduced. The recent progresses in pinning the grain growth at elevated temperature and nucleating the inter-granular ferrite from austenite, especially its mechanisms, have been summarized. The newly developed application of that technology in high heat input welding, rapid solidification and rolling processes, as well as in hot forged steel and heavy steel have also introduced. The developing trend of that technology has been forecasted.

生产实践

Practice on mould level fluctuation control of vertical-bending type caster in refining peritectic steel

SONG Ze-qi;CHEN Qing-quan;ZHANG You-hua

2007, 23(04):  7-10，1.  doi:

Asbtract ( 1976 )  

Related Articles | Metrics

The present paper analyzed the cause to the mould level fluctuation of vertical-bending type caster in casting the peritectic steel, and introduced the solution to the problem at No.2 steelmaking plant of WISCO including adjustment of the mould cooling and secondary cooling schedules, use of special casting powder and increase in the drawing force and etc.

Practice in refining 40Cr by converter

2007, 23(04):  11-13.  doi:

Asbtract ( 855 )  

Related Articles | Metrics

The present paper introduces the product properties of the round bar out of the 40Cr steel refined and rolled through the converter-LF reefing-Concasting process route.

Development and modification of air blow deslagging technology for hot metal desulfurization in ladle

Liu Xiao-qing;Tao yong-gang;Wang Qing-fang;Du Xiu-feng;Pan Yan-hua

2007, 23(04):  14-17.  doi:

Asbtract ( 2299 )  

Related Articles | Metrics

In hot metal desulfurization by pure Mg, problems frequently occur such as insufficient quantity of slag, high sulfur content and less flow-ability in slag , long time span for deslagging (up to 11 minutes) and heavy iron loss (up to 5 kg/t Fe), high resulfurization in steelmaking (up to w(S) 0.005 1 %) in NO.1 Steel-making Plant of WISCO. In order to solve those problems some technological measures have been taken in the Plant The efficiency of hot metal deslagging has been greatly improved ever since by adoption of the air-blow aided deslagging technology in which the air bubbling elements such as porous bricks are installed in the bottom of the ladle, properly selection of material for the air bubbling elements as well as appropriate selection of the installation position and continuously improvement of the technology in the actual production. As the results the average deslaggig time is cut to less than 7 minutes, average iron loss in deslagging declined from 5 kg/tFe to 3.5kg/tFe, average sulphur pick-up is declined from w(S) 0.005 1 % to w(S) 0.002 %,average life length is extended up to 110 .

Optimization of Secondary Cooling Water Calculation at The No.1 Slab Caster in Bayi Steel

2007, 23(04):  18-21.  doi:

Asbtract ( 1725 )  

Related Articles | Metrics

Based on analysis on the practical operation conditions in continuously casting steels Q235B and 08Al respectively in the No.1 Slab Caster of Sinkiang Bayi Steel, the secondary cooling water has been optimized by the universal static simulation software of slab continuous casting CCPS OFFLINE, which has been adopted in the actual casting process. From the production results it can be known that, the quality of slab (especially Tri-angle-zone crack) under the condition of the optimized secondary cooling water has been improved distinctly. It strongly demonstrates that the optimized secondary cooling water, obtained from the numerical heat-transfer & solidification simulation of slab continuous casting, has good reasonability and adaptability, and the simulation software can be widely used in design of the secondary cooling water for slab caster.

Optimization of secondary cooling scheme for bloom continuous casting of WISCO

2007, 23(04):  22-24，4.  doi:

Asbtract ( 1926 )  

Related Articles | Metrics

on the base of the bloom of No.1 Steelmaking Plant of WISCO, mathematical models of solidification and heat transfer for bloom have been established. According to requirements of metallurgical criteria for bloom solidifying process , the relation between secondary cooling water flux and casting speed were regressed. The new control model of secondary cooling water was established ,The bloom quality has been improved obviously since application of the new cooling water control model to actual production.

Study on intermedium cracks of continuous casting slab and improvement practice

2007, 23(04):  25-28.  doi:

Asbtract ( 1927 )  

Related Articles | Metrics

The type and cause to the formation of the intermedium cracks of the continuous casting slab are analyzed by macro examination and SEM and measures to eliminate the inter- medium cracks are put forward including compositions of the steel,secondary cooling schedule, pressure of driving rollers, soft reduction and support segments. Results show that the sulfur content of steel and support segments are main factors leading to the intermedium cracks. Since adoption of the improvement measures, the rate of the intermedium crack occurrence has been obviously descended.

Analysis on application of waste steel in converter refining

2007, 23(04):  29-32.  doi:

Asbtract ( 752 )  

Related Articles | Metrics

The waste slag steel is one of the main products out of the treatment of the converter steel slag. In the past this kind of waste steel was not properly used due to insufficient research on this subject 。In the No.2 Seel-making Plant of Jinan Iron & Steel Co., production experiments have been carried out in which the waste slag steel is directly added into the converter in lieu of the steel scraps. The effects of the slag steel on the converter steel-making as well as its economic efficiencies are analyzed. This new technology can contribute greatly to the reuse of the wastes and development of recyling economy.

试验研究

Fluid flow control for a single-strand tundish in slab continuous casting

2007, 23(04):  33-35.  doi:

Asbtract ( 720 )  

Related Articles | Metrics

Fluid flow in the single-strand tundish with different configuration in slab continuous casting at Nanjing Iron & Steel Co., had been studied in water modeling experiment to optimize the tundish configuration. With the optimal tundish configuration, the minimum residence time of liquid steel is increased by 1.2 times, the peak concentration time is increased by 97 %, and the dead volume fraction is decreased by 72 %. The experimental results showed that the special border turbulence inhibitor developed in the research can improve the flow characteristics parameters and fluid flow in the tundish greatly. It was shown from the results of industrial application that the inclusion area ratio of slab decreased by 32 % with the optimal tundish configuration.

Research on T91 steel refining technology through EAF-LF-VD process route

2007, 23(04):  36-38，4.  doi:

Asbtract ( 1975 )  

Related Articles | Metrics

The present paper studies the process adoptd in refining T91 steel through EAF-LF-VD processing route. To ensure the qualified content of [C] and [P] in liquid steel in the down stream processing steps, it’s of great neccesity to control the content of w(C) and w(P ) separately in 0.02 % and 0.004 %. By appropriately drawing up the alloy schedule and selecting the right alloy elements in LF process, the alloy content in liquid steel can be controlled within the specified limit.. By means of desulphurization in LF and VD vaccuum treatment the w(S ) content in steel can be reduced to below 0.005 %. Research indicates that refining T91 steel by this process is acceptable.

Study on composition of furnace charges in contemporary Steel-making flow route

2007, 23(04):  39-42.  doi:

Asbtract ( 1678 )  

Related Articles | Metrics

The BOF process route and EAF proces route are the main steelmaking process route today. Based on the calculation of material balance and heat balance, and on the analysis of tap to tap time, the conclusion can be made that there are an optimal proportion of hot metal charging in EAF steelmaking and an optimal proportion of cool metal charging in BOF steelmaking. For the NO.1 steelmaking and rolling mill of Anyang Iron and Steel Co.，Ltd.，the optimal proportion of hot metal charging in 100 t Shaft EAF is 31 % and the optimal proportion of cool metal charging with full scrap in 100 t BOF is 17 %.

Research and erosive mechanism analysis of advanced magnesite-chrome brick for RH furnace

2007, 23(04):  43-46.  doi:

Asbtract ( 1967 )  

Related Articles | Metrics

An advanced magnesite-chrome brick with good corrosion resistance and peel-off resistance is produced using the fused magnesite-chrome clinker and fused magnesia sand as the raw materials by means of refining matrix and richening matrix with Cr2O3. The microstructures of the original and residual bricks are anatomized and analyzed in detail through OM and SEM. The microstructure and corrosion mechanism of the original and residual brick are approached visually by “image as data”.

Intelligent prediction modeling and application research on the Angang FSF electrode

2007, 23(04):  47-51.  doi:

Asbtract ( 900 )  

Related Articles | Metrics

The electrode control system of alternating current electrical arc furnace is a multi-variable, nonlinear, parameter-time-varying and complicated strong coupling system and the classic control strategy is hard to acquire the good performance. Proceeding from actual application of FSF electrode control a variable structure Elman neural network prediction model is proposed based on a new hybrid generic algorithm in this paper.. This improvized hybrid generic algorithm can simultaneously and dynamically optimize the network structure, the weights and self-feedback gain .The improvized BP algorithm based Elman neural network and the variable structure Elman neural network proposed in this paper are both applied in identification of the electrode model. The simulation experiment based on the on-site data of Anyang Steel indicate that the structure variable Elman neural network overcomes the problem of complex network structure, which is brought by the complexity of electrode control system and limitation of weights by BP algorithm. The proposed method based on a new hybrid generic algorithm is of better identification performance ,better dynamic characteristic, quicker approach speed and better precision. Finally,the model applied in parameter tuning of electrode control system obtains the good control result，thus providing a solid theoretical basis for electrode control.

Application and numerical simulation on the wall design optimization for tundish

2007, 23(04):  52-55.  doi:

Asbtract ( 2133 )  

Related Articles | Metrics

With the purpose to bring down the inclusions rating of the steel billets through effective tundish wall design, 3-D numerical simulations have been carried out on the flow dynamic processes in the tundish of 4-strand CC in the 3rd Steel Plant Shougang and the effect of the flow field of liquid steel on the removal of inclusions in steel analyzed. Results of simulation and actual production show that by installation of high walls in the tundish inclusions can be reduced and V- shaped wall is more dependable and by use of the full wall with flow guiding orifices the inclusions can be more effectively removed since the flow field of the liquid steel is more appropriately distributed in the tundish.

Method of controlling solidification quality in electroslag remelting process

2007, 23(04):  56-58，6.  doi:

Asbtract ( 725 )  

Related Articles | Metrics

The different parameters symbolizing solidification quality and effect of solidification process parameters on solidification quality are analyzed. Relation between melting rate and solidification quality and how the reasonable melting rate is obtained is discussed. It’s an effective method to obtain reasonable solidification structure by computing temperature field and the secondary dendrite arm spacing using mathematical model.

辅助技术、材料及设备

Development of mold flux heavy rail steel at PZHISC

2007, 23(04):  59-62.  doi:

Asbtract ( 1713 )  

Related Articles | Metrics

In conjunction with the No.1 bloom caster process conditions in Panzhihua Iron and steel Company (PZHISC)，the present paper studies improvement in the lubrication performance and the melting uniformity of the flux by adding special constituents into the mold flux as the key elements and also discusses the suitable carbon mixing pattern for the mold flux. Industry tests show that the newly developed mold flux for heavy rail steels in possession of good performance well meets heavy rail steels production requirements of PZHISC No.1 bloom caster.