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STRUCTURAL CHANGE IN HEAT AFFECTED ZONE AND ITS INFLUENCE ON PROPERTIES OF WELDED WHITE CAST IRON

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Acta Metallurgica Sinica(English Letters) 1991年第9期4卷 191-195页

作者： zou zengda WANG Yong REN Dengyi Shandong Polytechnic University,Jinan,China Shandong Polytechnic Univ Jinan China

The structural change in heat affected zone(HAZ)and its influence on properties of welded white cast iron have been investigated by means of thermal cycle simulation *** structure of the white cast iron at peak temperature 800℃ was examined as cementite in pearlitic matrix,of which the hardness and impact toughness are the lowest,while the struc- ture after cyclic heating at high peak temperature is mainly cementite together with twin martensite,of which the hardness and impact toughness are rather *** phase bounda- ries in the structure of low hardness are smooth and regular as well as with fine precipitates. Both the cleavage and interphase fracture were revealed in the structure of low hardness,while the transgranular fracture was found in those areas of higher hardness.

关键词： white cast iron heat affected zone simulation technique

Effect of Thermal Cycle on Microstructure and Fracture Morphology in HAZ of HQ130 Steel

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Journal of Iron and Steel Research International 1996年第2期3卷 38-43页

作者： Li Yajiang zou zengda Cheng Zhunian Wei Xing Jiang Quanchang Shandong Polytechnic University Xiamen Engineering Machinery Ltd.

The effect of different peak temperature(Tp) and cooling time (t8/5) on microstructure, hardness, impact toughness and fracture morphology in the heat-affected zone (HAZ) of HQ130 steel was studied by using weld thermo-simulation test. Experimental results indicate that the impact toughness and hardness decrease with the decrease of Tpor increase of t8/5 under the condition of a single thermal cycle. There is a brittle zone in the vicinity of Tp= 800℃, where the impact toughness is considerably low. There is a softened zone in the vicinity of Tp=700℃, where the hardness decreases but the toughness increases. In the practical application of multi-layer and multipass welding, the welding heat input should be strictly limited (t8/5≤20s) so as to reduce the softness and brittleness in the HAZ of-HQ130 steel.

关键词： high strength steel welding thermal cycle heat-affected zone microstructure impact toughness

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Interfacial Microstructure between WC-Based Cermet and Cu Alloy

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Journal of Materials Science & Technology 2004年第6期20卷 731-734页

作者： Xinhong WANG, zengda zou, Sili SONG and Shiyao QUSchool of Materials Science and Engineering, Shandong University, Jinan 250061, China Sch. of Mat. Sci. and Eng. Shandong Univ. Jinan 250061 China

A WC-TiC-Co/CuZnNi composite layer was produced on 1045 steel substrate by means of inside-furnace brazing technique. The microstructure, phase constituent and interfacial diffusion behavior between cermet and CuZnNi alloy were investigated by means of scanning electron microscopy (SEM), transmission electron microscope (TEM), electron probe microanalyzer (EPMA) and X-ray diffraction. The results showed that microstructure of matrix was α and β phases. Cermet particies were surrounded by the α+β phases in the composite layer and their sizes were almost similar to those in original state. The interfacial zone was formed by the mutual diffusion of elements under the condition of high temperature. The interface consists of WC, TiC, CuZn, and CuNi phases, and there are no microcracks and inclusions near the interface.

关键词： Cu-base alloy WC-based cermet Interface behavior Microstructure

Effects of CeO_2 on microstructure and corrosion resistance of TiC-VC reinforced Fe-based laser cladding layers

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Journal of Rare Earths 2014年第11期32卷 1095-1100页

作者：张辉邹勇邹增大史传伟 Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education Shandong University

The effects of CeO2 on microstructure and corrosion resistance of TiC-VC reinforced Fe-based laser cladding layers were investigated. The results showed that carbides presented in cladding layers were TiVC2 and VC. A small quantity of CeC appeared with 2.0 wt.% CeO2 addition. The amount of lamellar pearlite increased while the amount of residual austenite decreased with increasing CeO2 addition. The corrosion resistance of cladding layers increased firstly and then decreased with the addition of CeO2 increasing. The EIS spectrum of the cladding layer without CeO2 was composed of an inductive arc at low frequency and a capacitive arc at high frequency. The cladding layer with 0.5 wt.% CeO2 addition showed the best corrosion resistance, and then the inductive arc at low frequency transformed into a capacitive arc.

关键词： laser cladding rare earths CeO2 corrosion resistance electrochemical impedance spectroscopy

Microstructure in the Weld Metal of Austenitic-Pearlitic Dissimilar Steels and Diffusion of Element in the Fusion Zone

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Journal of Materials Science & Technology 2001年第3期17卷 338-342页

作者： Yajiang LI, zengda zou and Bing ZHOU Department of Materials Engineering, Shandong University, Jinan 250061, China E-mail: yajli@*** Shandong Univ Dept Mat Engn Jinan 250061 Peoples R China

Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Microstructure, divisions of the fusion zone and elemental diffusion distributions in the welded joints were investigated. Furthermore, solidification microstructure and S-ferrite distribution in the weld metal of these steels are also discussed.

关键词： Microstructure in the Weld Metal of Austenitic-Pearlitic Dissimilar Steels and Diffusion of Element in the Fusion Zone

Oxidation process of lanthanum hexaboride ceramics

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Rare Metals 2002年第2期21卷 101-105页

作者： ZHENG Shuqi, MIN Guanghui, zou zengda , YU Huashun, HAN Jiande , and WANG Weiti School of Materials Science and Engineering, Shandong University, Jinan 250061, China School of Materials Science and Engineering Shandong University Jinan 250061

Oxidation process of lanthanum hexaboride (LaB_6) ceramic powderwas investigated. The laB_6 powder sma- ples were heated continuallyfrom room temperature to 1473 K at a heating rate of 10 k/min bydifferential scanning calorimetry. The oxidation tests were conductedat different exposure temeratures. The phases and morphologies of thesamples before and after exposure were analyzed by XRD and SEM. Itwas pointed out that before 1273 K, LaB_6 has high oxidationresistant ability, which was due to that the oxide layer hinders theoxygen diffusion from outer to the sur- face of Lab_6 grains.

关键词： lanthanum hexaboride oxidation mechanism ceramic

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磁场对双丝间接电弧焊熔滴过渡的影响

焊接学报 2011年第6期32卷 69-72,116页

作者：张顺善邹勇邹增大山东大学材料液固结构演变与加工教育部重点实验室济南250061

对磁场作用下的双丝间接电弧气体保护焊熔滴过渡变化规律进行了研究,通过励磁线圈对间接电弧施加外部横向及纵向磁场,磁感应强度值由特斯拉计侧出,熔滴过渡过程借助于高速摄像系统拍摄,并由示波器同步记录下电流和电压值的变化.研究表明... 详细信息

对磁场作用下的双丝间接电弧气体保护焊熔滴过渡变化规律进行了研究,通过励磁线圈对间接电弧施加外部横向及纵向磁场,磁感应强度值由特斯拉计侧出,熔滴过渡过程借助于高速摄像系统拍摄,并由示波器同步记录下电流和电压值的变化.研究表明,随正向横向磁场强度增加,熔滴颗粒变细,过渡频率增加,随负向横向磁场强度增加,熔滴颗粒变大,过渡频率减小;在纵向磁场作用下,熔滴脱离焊丝后发生偏转,且偏转程度随磁场强度增加而增大,在正向纵向磁场作用下,熔滴向阴极焊丝一侧偏转,在负向纵向磁场作用下,熔滴向阳极一侧焊丝偏转.

关键词：双丝间接电弧焊熔滴过渡外加磁场

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双钨极间接气体保护焊接电弧的数值模拟

机械工程学报 2013年第22期49卷 97-102页

作者：史传伟邹勇邹增大赵伟山东大学材料液固结构演变与加工教育部重点实验室济南250061

间接电弧焊接是一种新型的焊接方法,具有高效、节能、焊接应力和变形小的优点。为了研究间接电弧的电弧参数的分布特点以及这种焊接方法热输入低的根本原因,利用有限元分析软件,建立双钨极间接电弧的三维有限元数学模型,计算得到双钨极... 详细信息

间接电弧焊接是一种新型的焊接方法,具有高效、节能、焊接应力和变形小的优点。为了研究间接电弧的电弧参数的分布特点以及这种焊接方法热输入低的根本原因,利用有限元分析软件,建立双钨极间接电弧的三维有限元数学模型,计算得到双钨极间接电弧的温度、等离子体流速、电弧压力以及热流密度分布等特征参数;通过高速摄像拍摄到的电弧形态照片与计算得到的温度云图对比验证模拟结果的可信性。结果表明双钨极间接电弧面对称且向阳极方向偏转,呈上宽下窄的倒钟罩形态,阳极一侧的各项特征参数大于阴极一侧;与惰性气体钨极保护(Tungsten inert gas arc,TIG)焊接和等离子弧焊接相比,双钨极间接电弧被焊接工件不接电极,主要靠热流密度、等离子体流速、电弧压力等参数都比较低的弧柱区端部加热,造成工件焊接热输入低、熔深浅。

关键词：计算机模拟有限元法电弧双钨极间接电弧焊接

Cr对TiC-VC增强铁基熔覆层耐蚀性及耐磨性的影响

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强激光与粒子束 2014年第3期26卷 81-86页

作者：张辉邹勇邹增大史传伟山东大学材料液固结构演变与加工教育部重点实验室济南250061

通过X射线衍射、扫描电子显微镜、能谱仪、极化曲线和磨粒磨损实验分析,研究了不同Cr加入量对TiC-VC增强铁基激光熔覆层耐蚀性和耐磨性能的影响。结果表明:熔覆层中物相主要为α-Fe,TiC,VC和TiVC2。随着Cr加入量的增加,伴随有残余奥氏体... 详细信息

通过X射线衍射、扫描电子显微镜、能谱仪、极化曲线和磨粒磨损实验分析,研究了不同Cr加入量对TiC-VC增强铁基激光熔覆层耐蚀性和耐磨性能的影响。结果表明:熔覆层中物相主要为α-Fe,TiC,VC和TiVC2。随着Cr加入量的增加,伴随有残余奥氏体及Cr3C2的出现,且Cr3C2呈长条状部分聚集、部分单独分布。熔覆层的耐蚀性与耐磨性随Cr加入量的增加呈现先增加后降低的趋势。熔覆粉末中加入适量的Cr元素能显著提高熔覆层的硬度与耐蚀性。当添加质量分数为3.0%的Cr时,熔覆层硬度高达1090HV0.2,且相同磨损条件下熔覆层磨损失重仅约为Q235钢的1/26;当添加质量分数为9.0%的Cr时,所得熔覆层的耐蚀性最好,约为不添加Cr时的3.26倍。

关键词：激光熔覆耐蚀性耐磨性