Effect of water quenching processing parameters on the mechanical properties of a cold-rolled C-Mn-containing steel sheet

Cold-rolled advanced high-strength steel sheets have become the material of choice for the automotive industry because of their unique attributes of high strength and balanced mechanical properties.High-hydrogen gas jet cooling and water quenching are the most commonly used ultrafast cooling technologies for producing martensite-containing high-strength steel sheets.The water quenching technology ensures the fastest industrial cooling rate of 1 000 K/s;therefore,it has the highest potential with respect to saving alloys.In this study,the water quenching of a C-Mn-containing steel sheet is simulated during continuous annealing to investigate the effect of water quenching and tempering parameters on its mechanical properties.The results reveal that at low quenching temperatures,the strength of the steel sheet decreases as the soaking temperature increases.However,at high quenching temperatures,a high soaking temperature corresponds to increased strength after quenching,regardless of whether the material was austenitized in the single austenite zone or the inter-critical zone.Therefore,a high quenching temperature always results in a high strength and a high yield ratio after quenching.Low-temperature overaging(tempering) considerably influences the yield strength and yield ratio,and the extent of this influence is correlated with the soaking temperature.

Effect of annealing parameters on mechanical properties of cold-rolled martensitic steel sheets

Cold-rolled martensitic steel sheets produced on continuous annealing lines with water quenching facility,have advantages of high strength and low alloying element contents.These are in good accordance with the trend of light-weighting and fuel saving for automotive steel.In this article,a cold-rolled martensitic steel is studied to investigate the effect of annealing parameters on its mechanical properties.It is found that the quenching temperature and the slow cooling speed as well as the overageing temperature have significant influence on the strength of the experimental steel.The temperature zone at which the austenite decomposition is slow or has not started may be chosen as the quenching temperature to ensure the steel’s strength stability.The slow cooling speed also influences the steel’s strength greatly.A high cooling rate will lead to significantly higher strength.Tempering would decrease the steel’s tensile strength but would increase its yield strength.

Development and application of Baosteel's cold-rolled martensitic steel sheets

Cold-rolled martensitic steel sheets are becoming widely applied in the automotive industry because of their ultra-high strength,which may result in satisfactory weight reduction. The grades of martensitic steel sheets are classified based on their tensile strength,which ranges from 980 to 1 700 MPa. The main applications include a series of structural parts of uniform cross-section or simple shape,such as bumper beams,door beams and door sills,etc. The study and development of cold-rolled martensitic steel sheets date back to 2007 in Baosteel,and some grades became commercially available in 2009. By 2015,Baosteel had commercially supplied thousands of tons of these steel sheets with tensile strength up to 1 400 MPa. Currently,1 500 MPa martensitic steel sheet is commercially available and 1 700 MPa martensitic steel sheet has been successfully produced. The process technology and application guides of Basoteel ＇s cold-rolled martensitic steels are summarized and analyzed in order to assist ongoing research and ensure correct applications of these ultra-high strength steel sheets.

Properties of ultra-low carbon,cold-rolled sheet steels containing titanium or boron for use in enameling

Ultra-low carbon（ULC）,cold-rolled sheet steels for porcelain enameling containing alloys of titanium and boron are studied. The microstructure,mechanical properties,inclusions,and precipitates of the sheet steels are analyzed. The hydrogen permeation time of the sheet steels as-annealed and after skin-passed or cold-rolled at different reductions are measured. It is show n that the sheet steels possess different features of enameling properties in hydrogen permeability,fishscale resistance,and pinhole resistance.

Research and application on the automatic measuring device for testing transverse thickness difference of cold-rolling steel sheet

Many advanced technologies have been applied in developing the automatic measuring device for testing transverse thickness difference of cold-rolling steel sheet,such as the technologies of automatic control,sensor measurement,marking identification,photographic location,computer application and information transmission.This measuring device can measure the transverse thickness difference of the steel plate accurately and quickly,with a high detection level of automation.It is an effective detection equipment for transverse thickness control of steel plate.Horizontal width of steel plate measuring 0.8-1.4 m, horizontal measurement point positioning accuracy±0.02 mm,thickness range 0.2-2.0 mm, measurement accuracy within±1μm.

核能行业数据安全标准体系研究

随着核能发电规模化批量化高速发展以及数据驱动的工业数字化转型程度逐步加深,核能行业数据安全问题逐步显现并日益突出。分析核能行业数据安全所面临的风险,研究我国核能行业数据安全标准化工作现状及存在的问题,提出核能行业数据安全标准体系框架和标准主要内容的建议,最后对体标准体系建设过程中的难点进行分析,并对下一步工作进行展望。通过研究将为我国核能行业数据安全建设、管理、应用与保障提供有效的技术支持与指导。

冷轧厂薄带钢高效生产的问题及解决方案分析

热镀锌板具有抗腐蚀强、易于深加工、使用寿命长、成本低以及表面美观等特点,主要用于家用电器、汽车等产品的内部构件和面板应用。随着家电板、汽车板工业的发展,家电和汽车所用的镀锌板占全国钢产量的比例逐步提升。随着国内外家电板、汽车板轻质化和高质量的要求,客户对产品表面质量要求越来越严格。针对生产线在提速增产过程中出现的入口跑偏、工艺段带钢表面质量缺陷和薄带钢薄锌层产速受限问题,提出了相应的改进措施。优化后,不仅提高了产量,而且提高了产品质量。

Risk Communication： Survey on Quality of Safety Data Sheets of Agricultural Substances

Manufacturers of chemicals are responsible for setting up a list of tools, including labels and safety data sheets, in order to provide adequate information about dangerous properties being labels and safety data sheets the main instruments for the immediate advice about dangerous substances and preparations for general public and workers. While correct labelling gives the possibility to general public to recognise the risks arising from handling and use of dangerous chemicals, safety data sheets are provided for professionals in order to allow safe handling and storage of dangerous chemicals in work places. Information contained in safety data sheets are also designed to suggest safety measures to be taken for the protection of workers as well as precaution measures and adequate actions to be taken in the case of accident. This project has critically revised the information contained in a list of safety data sheets of active ingredients provided for plant protection products, in order to assess the quality and the consistency of the data contained. Reported data have been then compared to published data. Considerable deficiencies/mistakes/inconsistencies have been found in the data reported along the safety data sheets of the examined substances, showing an urgent need of improving the enforcement related to a systematic recognition in this field as well as training of people involved in compilation of safety data sheets by producer side.

Surface Defects of Cold-Rolled Ti-IF Steel Sheets due to Non-Metallic Inclusions

Surface defects of the cold-rolled sheets of Ti-IF steel were studied and analyzed. After analyzing surface defects of cold-rolled sheets, such as shelling defects, holes and sliver defects by SEM/EDS, a variety of inclusions were found. In addition, the distribution of macro-inclusions in slabs was analyzed by MIDAS method. The results show the macroscopic inclusion bands of head slabs and normal slabs are in 1/8 slab thickness regions of both inner arc side and outer arc side. The formation process of the defects in the cold-rolled sheets was simulated with an experimental cold-rolling machine for comparison. The results show that there were three kinds of inclusions underneath the surface defects: Al2O3, SiO2 and particles from slag entrainment, which were the main reason for defect formation during cold rolling.

Causes of surface stripe cracks of Ti–4Al–2V alloy cold-rolled sheet

The stripe cracks which formed along rolling direction on the surface of Ti–4Al–2V alloy cold-rolled sheet were observed by stereoscope, scanning electron microscope（SEM）, and energy-dispersive spectrometer（EDS）. Morphology analysis indicates that cracks are dominantly in zigzag shape, with 10–30 mm in length and less than 10 lm in depth, and there is no evidence of crack tips. Chemical composition analysis shows that crack regions feather high oxygen concentration while smooth surface is at normal oxygen level. It is obvious that the occurrence of strip cracks is mainly related to residual oxide on the surface of Ti–4Al–2V alloy cold-rolled sheet.

河道内水生植物曝气浮岛生态修复技术

植物及曝气浮岛通过以水生植物、微生物为主的食物链发挥生态净化功能,同时利用人工纤维填料等富集微生物,牡蛎壳吸附磷,多方位净化水体。以坚实的水生树木为主轴,不仅提高生态浮岛的抗风浪性能,还增加了生态浮岛的生物多样性,从而也减小了生态浮岛对季节性的依赖。新型组合生态浮岛安装有喷淋系统纳米增氧器并设有增氧曝气管,浮岛区域外安装有喷淋系统,有效增加了水体流动性和含氧量,提升了生态浮岛的深层净水能力,保证了沉水植物的采光与成活率。

动物胶原纤维与植物纤维复合抄片结构的研究

将皮革固体废弃物制成的动物胶原纤维浆与植物纤维浆抄片，利用扫描电镜（ＳＥＭ） 对抄片结构进行了观察、拍照与分析。

制革含铬废革屑/植物纤维复合材料的制备研究

研究了经过化学 -机械处理后的制革含铬废革屑与植物纤维混合抄片的性能。结果表明 :通过适当处理后 ,制革含铬废革屑可以被制成造纸所用的胶原纤维浆 ,胶原纤维与植物纤维按适当的比例混合抄片 。

一种新型润滑剂在扩孔成形中的应用研究

通过 分别在植 物粉-水 基润滑剂、聚乙烯 薄膜、机 油和油脂 4种润滑 条件 下进行 的薄 钢板 扩孔成形试验,研究 了植物粉-水基润滑剂的应用性能。 结果表明 :在 4种 润滑剂中,使用植 物粉-水 基润滑剂的薄钢 板平均扩 孔率最高 ,凸模极 限行程最 大,扩孔 成形性最 好;植物 粉-水基 润滑剂 的减摩 润滑 效果 与板料种类有关,σs/σb 较低和 δ较高的板料效果较差。

纤维素乙醇微型工厂的Aspen plus流程模拟

在Aspen plus平台上对日产1 kg乙醇的纤维素乙醇微型工厂流程建立流程模拟模型,并构建了完整的生物质组分物性数据库;对微型工厂流程进行了基于微型工厂实验数据和严格热力学模型基础上的物料衡算和能耗计算,并进行了水分回收分析和综合能耗折算。结果表明:在纤维素乙醇微型工厂最大生产能力下,用玉米秸秆生产1 kg纤维乙醇的水用量2.595 7 kg,蒸汽用量3.605 4 kg,废水量8.061 6 kg,均低于目前工艺水平下的玉米淀粉生产乙醇的水用量和废水量;1 kg乙醇消耗各种形式能量36.515 2 MJ,产出能量为53.574 9 MJ,能量产出大于能量投入;1 kg乙醇的综合能耗折合1.826 9 kg标准煤,加工过程中的产出能量折合1.828 0 kg标准煤,能量投入和能量产出基本平衡。

地膜小麦与套种的增产和减沙效益研究

通过三年试验 ,渭北地区种植地膜小麦一般增产 16 .2 %～ 2 2 .6 % ,若套种秋作 (马铃薯 ) ,增产幅度达5 8.7%。地膜小麦的增收效益显著 ,分别达 6 2 81元 / hm2 和 10 45 6 .7元 / hm2 。地膜小麦起垄耕作 ,或套种秋作起垄管理 ,水土保持效益明显。仅起垄种植可减沙 2 8.3% ,起垄留残茬减沙 5 4.6 % ,起垄套种马铃薯减沙 86 .5 %以上。建议在渭北地区推广地膜小麦与套种秋作 ,对实施“山川秀美”工程和农民脱贫致富均有重要意义。

片状电感探针研制及其在乙烯装置的应用

片状电感探针是腐蚀在线监测系统的重要组成部分,由于其片状的结构,尤其适合小管径管线的腐蚀监测。为了模拟管线的腐蚀状况、评价片状电感探针监测数据的准确性。进行了实验室对比实验研究。结果表明:片状电感监测的腐蚀速率略小于同期挂片数据,但二者相对误差未超过20 %,说明监测数据可靠;通过在中国石油天然气股份有限公司独山子石化分公司现场应用,证明片状电感探针的运行稳定,可有效地指导设备的防腐蚀工作。

旱地玉米不同种植方式生态效应初报——玉米膜外侧晚播栽培技术

在半干旱地区(长治襄垣县),使用中单2号玉米品种,三年平均膜侧种植晚期播种比正常播期下膜内种植和露地种植亩增产155.2kg和199.6kg,增产率为30.8％和43.5％。究其原因,一是增温缓温;二是增墒节墒;三是适时晚播有利于促进光合产物的合成与积累。

种植屋面用耐根穿刺防水卷材植物检测试验(第一批)阶段性检测结果与分析

对种植屋面用耐根穿刺防水卷材试验的第一批参试卷材的阶段性检验结果进行了通报。根据试验阶段性结果,证明了进行耐根穿刺试验对于种植屋面工程的重要性;同时提醒专业人士,种植屋面选用防水材料,既要考虑其耐根穿刺能力,更要考虑其耐腐蚀性。

基于PDA的冷轧薄板厂物流跟踪管理系统的研究

基于移动数据库技术的概念、理论和方法,结合现代通信设备,设计了冷轧薄板厂物流跟踪管理系统。针对冷轧薄板厂实际情况规划出了无线网络节点配置,并对系统的体系结构设计、功能实现设计以及系统实现的关键技术进行了阐述。物流跟踪管理系统有助于提高冷轧薄板厂的物流调度速度,从而提高企业信息化水平和生产效率,大幅降低企业生产成本。