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Effects of CeO_2 additives on the microstructure and mechanical properties of WC-Al_2O_3 composites

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Baosteel Technical Research 2015年第3期9卷 17-22页

作者： QU Haixia WU Qiong wen hongquan Research Institute Baoshan Iron & Steel Co.Ltd.

To improve the mechanical properties of WC-Al2O3 composites, the effects of trace amount of CeO2 additives on the microstructure and mechanical properties of the WC-Al2O3 composites prepared by hot pressing were investigated. The results revealed that the WC-Al2O3 composites doped with 0.1% CeOz possessed refined microstructure and enhanced mechanical properties compared with that of the undoped WC-Al2O3composites. Trace CeO2 suppressed the decarburization of WC, promoted the microstructural refinement, and improved the interface coherence of the WC matrix and Al2O3. When 0.1% CeO2 was added to the WC-Al2O3 composites, the effect of CeO2 resulted in the achievement of a relative density of 98.82% with an excellent Vickers hardness of 16.89 GPa, combining a fracture toughness of 9.85 MPa. m1/2 with an acceptable flexural strength of 1 024.05 MPa.

关键词： CeO2 additives microstructure mechanical properties WC-Al2O3 composites

Numerical simulation of multistage induction heating of coated steel tubes in Baosteel

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Baosteel Technical Research 2022年第1期16卷 42-46页

作者： HE Chunyao wen hongquan WU Cunyou Tube Pipe&Bar Business UnitBaoshan Iron&Steel Co.Ltd.Shanghai 201900China Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai 201999China

The electromagnetic and temperature fields in the multistage intermediate-frequency induction heating of coated steel tubes were calculated using a numerical *** influence of the voltage and frequency on the parameters of power circuit and heating temperature of the steel pipe was also *** results indicate that:(1) the electromagnetic field of induction heating is concentrated between the induction coil and steel tube and dissipated more at both ends of the coil;(2) during the induction heating,the temperature difference between the outer and inner walls of the steel pipe is approximately 3040 K,and the two temperatures rapidly tend to be the same after exiting the induction heater;(3)during the natural cooling,the temperature drop of the steel tube in the low-temperature section is approximately 10 K,and that in the high-temperature section is approximately 20 K;(4)the appropriate induction heating frequency and matching capacitance should be selected,so that the temperature of the steel pipe,especially at the outer wall,meets the coating process requirements,and as to achieve a synchronous improvement of the power efficiency and heating *** study is beneficial to building a more low-consumption and high-efficiency coating line of large-diameter steel pipes in Baosteel.

关键词： steel tube coating line induction heating numerical simulation

Molten steel level stability in continuous casting slab mold under electromagnetic stirring

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Baosteel Technical Research 2019年第1期13卷 25-31页

作者： wen hongquan WU Cunyou ZHOU Yueming Research Institute Baoshan Iron & Steel Co.Ltd.

Fluctuation of molten steel level in continuous casting process is a critical issue. The analytic function for the liquid steel surface stability index( F) of the continuous casting slab mold under the action of electromagnetic stirring was derived. The effects on the F value of the electromagnetic field,casting mold,submerged entry nozzle,and casting speed were observed,and the stability of the process parameters of a practical continuous casting system was evaluated. The main results generated are as follows:①Based on the free flow jet theory,a formula is established for the level stability index of continuous casting slab mold under electromagnetic stirring.②According to the results of calculation,the various parameters in decreasing order of the magnitude of their influence are magnetic flux density,nozzle submersion depth,casting speed,slab width,stirring current frequency,and nozzle side-hole inclination angle.③For practical continuous casting with a slab thickness of 230 mm,the calculated F values are between 3 and 5 for different matches between slab width and casting speed,but the parameter optimization space is much larger for wider slab widths and lower casting speeds.

关键词： level stability free flow jet electromagnetic stirring F -index continuous casting mold

Rolling-contact-fatigue behavior in backup roll of 5% Cr forged steel

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Baosteel Technical Research 2018年第1期12卷 41-46页

作者： wen hongquan QIN Xiaofeng WU Qiong Research Institute Baoshan Iron & Steel Co.Ltd. College of Mechanical Engineering Taiyuan University of Technology

With a focus on the backup roll, a rolling-contact-fatigue experiment was performed on samples of 5% Cr forged steel. The P-S-N fatigue curves were determined and the fatigue strength was calculated. The emergence of cracks on the test-sample surfaces was observed at different fatigue cycles. A micro-hardness tester was used to measure the hardness of the subsurface fatigue layer. The microstructures were analyzed at various magnifications with an optical microscope, scanning electron microscope, and transmission electron microscope. Based on these tests, the rolling-contact-fatigue mechanism of the large forged steel backup roll was also considered. The results showed that the contact-fatigue strength of the tested backup roll steel was 1 249 MPa;the surface fatigue crack lengthened continuously as the number of cycles increased and followed an S-shaped curve; the subsurface fatigue hardness reached its highest value at about 90 （HV） increment from the matrix hardness of 540 （HV） in the backup roll; the subsurface martensite/bainite microstructure was crushed and the dislocation density was greatly increased. Under alternating contact stresses,the surface/subsurface material was damaged and exhibited many microdefects. At the least, the surface fatigue layer on backup rolls should be fully removed before the microcracks enter a period of rapid propagation.

关键词： contact fatigue fatigue property crack propagation microstmcture failure mechanism 5% Cr forged steel backup roll

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自生复合Cu-Cr合金的定向凝固特性

稀有金属材料与工程 2000年第5期29卷 307-310页

作者：彭立明毛协民温宏权上海大学上海200072 宝山钢铁公司设备所上海201900

采用定向凝固连续铸造技术成功制备了纤维增强的自生复合 Cu- Cr合金电车线线坯 ,并对自生复合 Cu- Cr合金的定向凝固特性 ,包括组织形态、枝晶间距及纤维长度等 ,作了详细的研究。实验结果表明 :保持平面状或胞状的凝固界面有利于纤维... 详细信息

采用定向凝固连续铸造技术成功制备了纤维增强的自生复合 Cu- Cr合金电车线线坯 ,并对自生复合 Cu- Cr合金的定向凝固特性 ,包括组织形态、枝晶间距及纤维长度等 ,作了详细的研究。实验结果表明 :保持平面状或胞状的凝固界面有利于纤维状的自生复合组织的形成 ;当 GL=2 10℃ / cm,V=0 .6 mm/ min时 ,Cu- 0 .8% Cr合金凝固界面呈平面状 ;增加凝固速率 ,Cu- Cr合金的一次枝晶间距呈先增大后减小的规律。

关键词：自生复合 Cu-Cr合金定向凝固接触导线接触网

On Wear Morphology and Mechanism of Backup Roll

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On Wear Morphology and Mechanism of Backup Roll

第十届中国钢铁年会暨第六届宝钢学术年会

作者： wen hongquan Wu Qiong Yao Lisong Sun Dale Research Institute of Baosteel

The backup roll（BUR） is an important part in continuous rolling. The main failure form is wear of its surface. In this paper, to clarify the wear mechanism and find out the effective countermeasures to reduce the wear loss of BUR, taking samples from the normally off-line backup rolls in 2050 hot strip mill and 1550 cold strip mill of Baosteel, the surface wear morphology is investigated by means of the stereomicroscope, confocal laser scanning microscope, and scanning electron microscope, et al. The results show that the wear mechanism of backup roll is a combination of abrasive and corrosive wear. The hot rolling BUR is mainly of abrasive wear and corrosive wear, while the cold rolling BUR is mainly of abrasive wear. The main countermeasures to decrease the backup roll wear include:（1） strengthened the matrix strength（hot/cold rolling BUR）;（2） fine matrix microstructure（hot/cold rolling BUR）;（3） minimization of micro segregation（hot rolling BUR）;（4） solution of undissolved carbides（hot rolling BUR）.

关键词： backup roll wear morphology wear mechanism countermeasure

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大型锻钢支承辊材料的接触疲劳性能研究

上海金属 2018年第3期40卷 18-22页

作者：温宏权姚利松宝山钢铁股份有限公司研究院上海201900

通过滚动接触疲劳试验,测试了进口与国产两种5%Cr支承辊用钢的P-S-N疲劳曲线与疲劳强度,分析了试样接触疲劳层的显微硬度与组织特征,探讨了大型锻钢支承辊的接触疲劳机制。结果表明,(1)进口支承辊钢的疲劳强度为1 249 MPa,国产支承辊钢... 详细信息

通过滚动接触疲劳试验,测试了进口与国产两种5%Cr支承辊用钢的P-S-N疲劳曲线与疲劳强度,分析了试样接触疲劳层的显微硬度与组织特征,探讨了大型锻钢支承辊的接触疲劳机制。结果表明,(1)进口支承辊钢的疲劳强度为1 249 MPa,国产支承辊钢的疲劳强度为1 070 MPa,进口支承辊由于晶粒细小具有更高的抗接触疲劳能力;(2)在交变接触应力的作用下,支承辊疲劳层呈现局部硬度升高、马氏体和贝氏体破碎等一系列性能与组织结构变化;(3)随着循环使用及修磨次数的增加,支承辊接触疲劳最大损伤位置向表面移动,累积损伤值逐渐增大,最终二者均趋于某一恒定值。

关键词：接触疲劳显微组织疲劳损伤支承辊