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The test device for heat friction coefficient of high strength steel

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Engineering Sciences 2012年第6期10卷 75-78页

作者： Sun Zhifu Ma Mingtu Ma Fangwu Guo Yihui song leifeng Yao Zaiqi Chongqing New Materials Engineering Center China Automotive Engineering Research Institute Co.Ltd. Geely Automobile Research Institute

Using high strength steel and ultra-high strength steel in hot stamping and automobile parts is one of the most important ways of the automobile lightweight,which is the development trend of automobiles *** this paper, the development of test device for heat friction coefficient by high strength steel can provide important technical parameters for hot stamping process,making the right selection of equipment types,mold design,technology optimization,and research and development of lubrication medium of press *** the same time,the experiments indicate that the instrument has not only accurate test result but also good repeatability.

关键词： automobile lightweight modern automobile heat friction coefficient

Simulation about hot stamping of ultra-high strength steel on the basis of lightweight technology

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Engineering Sciences 2012年第6期10卷 67-70页

作者： Liu Qiang Ma Fangwu Wang Xiaona Yao Zaiqi song Wei Zhao Fuquan Ma Mingtu song leifeng Geely Automobile Research Institute China Automotive Engineering Research Institute Co.Ltd.

With the development of automobile lightweight,it is very necessary to apply the ultra-high strength steel parts manufactured by hot stamping,which offers the possibility to reduce the weight of automobiles and maintain the safety *** order to complete hot stamping,it is important to design the structure of parts reasonably,which is related with reasonable matching of *** objective of this paper is to guide the design of parts manufactured by hot stamping and find the forming technical requirements of vehicle *** experiments,the paper obtains the stress and strain curves at different deformation temperatures and strain *** on experimental data, the constitutive relationship model is established which can reflect the deformation capacity of ultra-high strength steel during the process of hot *** with finite element simulation results of hot stamping by commercial software AUTOFORM,transfer path of load and matching law of strength,the paper determines the design criteria and forming technical requirements of parts manufactured by hot *** the same time,the impact performance of front cross member internal plate is taken into consideration.

关键词： ultra-high strength steel hot stamping finite element simulation lightweight technology

Numerical simulation of hot stamping of side impact beam

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Engineering Sciences 2012年第6期10卷 62-66页

作者： Guo Yihui Ma Mingtu Fang Gang song leifeng Liu Qiang Wang Xiaona Zhou Dianwu China Automotive Engineering Research Institute Co.Ltd. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Geely Automobile Research Institute

Ls-DYNA software is adopted to conduct research of numerical simulation on hot stamping of side impact beam to calculate the temperature field distribution, stress field distribution, forming limit diagram （FLD） figure, etc. in the course of hot stamping so as to predict and analyze the formability of parts. ProCAST software is employed to conduct research of numerical simulation on solid quenching course concerning hot stamping to calculate temperature field distri- bution of tools and component of muhiple stamping cycles. The results obtained from numerical simulation can provide significant reference value to hot stamping part design, formability predication and tools cooling system design.

关键词： hot stamping numerical simulation FLD temperature field

Study on the resistance spot welding technology of 22MnMoB hot stamping quenched steel

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Engineering Sciences 2014年第5期12卷 45-53页

作者： Feng Yi Ma Mingtu Hua Fu'an Zhang Junping song leifeng Jin Qingsheng China Automotive Engineering Research Institute Co. Ltd. Chongqing 401122 China The State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China

In this paper, the spot welding technology of a new kind of 22MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder. Through a series of technology and test experiments, we have obtained the optimal spot welding technological parameter condition. According to the results, the relations among spot welding technological parameter, welding nugget, mechanical property and fracture mode were discussed. The effects of all the welding parameters such as welding current, welding time and electrode force on the quality of joint can be boiled down to one thing--the diameter of welding nugget. The experimental results showed that welding nugget diameter determines the mechanical property of spot welding joint and the relation between welding nugget diameter and the mechanical property of joint presents a kind of linear mathematic representation. There are two typical fracture models of 22MnMoB hot stamping quenched steel sheet, i.e., interracial fracture and nugget pullout. Other than mild steel or normal high strength steel, in the shearing tensile test, hot stamping quenched steel has a great tendency to fail in interfacial mode due to the effects of high strength matrix structure, welding soft zone and the porosity level of fusion zone.

关键词： hot stamping quenched steel resistance spot welding maximum shearing force nugget diameter soft zone fracture mode

Research on plastic fender development and key technologies

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Engineering Sciences 2012年第6期10卷 89-91页

作者： Yang Hao Li Li Liu Qiang Yang Anzhi Ma Fangwu Zhao Fuquan Guo Yihui song leifeng Geely Automobile Research Institute China Automotive Engineering Research Institute Co.Ltd.

Automotive lightweight and safety performance come into play as key technologies to promote competiveness, and average applied amount of automotive plastics has become a significant sign for automotive industrial development level of a *** performances of a vehicle with plastic automotive fenders are analyzed in the *** research is emphasized on sinking-resistance and pedestrian protection performance of the plastic fenders by studying plastics characteristics and simulation *** offers references for engineering design in which both automotive lightweight and safety performance are achieved and well balanced.

关键词： plastic fender lightweight safety simulation analysis

自由基清除剂及高压氧治疗血管性认知功能障碍的研究

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航空航天医学杂志 2012年第6期23卷 676-678页

作者：宋雷凤黑龙江省医院神经内科哈尔滨150036

目的:观察自由基清除剂(FRS)联合高压氧(HBO)治疗血管性认知功能障碍(VCI)的临床疗效。方法:164例血管性认知功能障碍患者,随机分为高压氧组、自由基清除剂组、高压氧+自由基清除剂组及对照组。比较治疗前后各组简易智力状态检查量表(MM... 详细信息

目的:观察自由基清除剂(FRS)联合高压氧(HBO)治疗血管性认知功能障碍(VCI)的临床疗效。方法:164例血管性认知功能障碍患者,随机分为高压氧组、自由基清除剂组、高压氧+自由基清除剂组及对照组。比较治疗前后各组简易智力状态检查量表(MMSE)及日常生活能力评定量表(ADL)的评分。结果:治疗后高压氧组、自由基清除剂组、高压氧+自由基清除剂组其MMSE及ADL评分均较治疗前明显改善,且均优于对照组,高压氧+自由基清除剂治疗组又优于单纯自由基清除剂组和高压氧治疗组。结论:自由基清除剂联合高压氧治疗可明显改善VCI患者的MMSE、ADL评分,疗效提高,值得临床进一步推广应用。

关键词：自由基清除剂高压氧血管性认知功能障碍

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维生素D与老年人认知功能障碍的相关性研究

中国继续医学教育 2016年第2期8卷 54-55页

作者：王连堃宋雷凤黑龙江省医院南岗院区哈尔滨150001

目的研究25-二羟维生素D（25-OH-D）与老年人认知功能障碍的相关性。方法选取我院2014年10月-2015年3月老年科病情稳定的老年患者150例,分为三组进行临床和神经系统检查,血标本检测血清25-OH-D,同时进行神经心理量表-蒙特利尔认知评估... 详细信息

目的研究25-二羟维生素D（25-OH-D）与老年人认知功能障碍的相关性。方法选取我院2014年10月-2015年3月老年科病情稳定的老年患者150例,分为三组进行临床和神经系统检查,血标本检测血清25-OH-D,同时进行神经心理量表-蒙特利尔认知评估量表（MoCA）评估。结果 150例研究对象25-OH-D浓度及平均浓度,均低于30 ng/ml。多因素回归分析显示,25-OH-D与年龄、受教育程度独立相关。结论维生素D缺乏在老年人中较普及,随着年龄的增加,认知功能障碍的发生率急剧增加,同样水平的维生素D人群,受教育程度越高,认知功能障碍的发生率越低。

关键词： 25-二羟维生素D 认知功能障碍老年

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前防撞梁零件的热成形试制研究

中国工程科学 2014年第1期16卷 76-80页

作者：郭怡晖马鸣图张宜生宋磊峰方刚中国汽车工程研究院股份有限公司重庆400039 华中科技大学材料科学与工程学院武汉430074

针对某车型前防撞梁零件开发热成形模具,并进行热冲压成形试验,对成形后的零件进行激光扫描以及金相组织、显微硬度和力学性能检测。结果表明:所试制的零件形状符合设计要求,热成形后零件为马氏体组织,显微硬度在HV400以上,样件屈服强度... 详细信息

针对某车型前防撞梁零件开发热成形模具,并进行热冲压成形试验,对成形后的零件进行激光扫描以及金相组织、显微硬度和力学性能检测。结果表明:所试制的零件形状符合设计要求,热成形后零件为马氏体组织,显微硬度在HV400以上,样件屈服强度在1 000 MPa以上,抗拉强度在1 400 MPa以上,断后延伸率在10%以上。

关键词：前防撞梁热成形力学性能

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三种强度级别的双相钢成形性能研究

中国工程科学 2014年第1期16卷 66-70页

作者：方刚马鸣图 Dongun Kim 金庆生宋磊峰蒋松蔚中国汽车工程研究院股份有限公司重庆400039 Metal Forming Research Group POSCO Global R&D Center Korea 406-840

对三种不同强度级别、不同厚度的双相钢进行了系统的成形性试验,综合分析了双向钢的力学性能、杯突性能、冷弯性能、成形极限。研究表明:双向钢的延伸率A及加工硬化指数n值随强度级别上升而下降;杯突试验结果表明,杯突的高度随双相钢强... 详细信息

对三种不同强度级别、不同厚度的双相钢进行了系统的成形性试验,综合分析了双向钢的力学性能、杯突性能、冷弯性能、成形极限。研究表明:双向钢的延伸率A及加工硬化指数n值随强度级别上升而下降;杯突试验结果表明,杯突的高度随双相钢强度级别上升而下降,随材料厚度升高而升高;双相钢冷弯性能随材料强度级别上升而下降;双轴应变下的胀形试验表明双向钢具有良好的成形性;基于软钢的FLD0(是指成形极限曲线FLC与纵坐标e1的交点的纵坐标值,它是FLD(成形极限图)上的重要的特征点)经验公式并不能直接套用在双向钢上。

关键词：双相钢力学性能成形极限