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Mechanical Method Determining Precipitation in an Ultra-Low Carbon Bainitic Steel

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 115-118页

作者： zijiu dang Yan Thang Jun Ke Xinlai He Shanwu Yang(State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China)(Applied Science School, University of Science and Technology Beijing, Beijin State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Applied Science School University of Science and Technology Beijing Beijing 100083 China

Stress relaxation was chosen as the best method for monitoring the precipitation process. Tests were carried out on an ultra-low carbon bainitic steel containing Mn, Nb and B over 800~950℃. Specimens were solu- tion treated at 1250℃ for a certain holding period. A prestain of 20% was applied at a strain rate of 0.1/s. The exper- imental results are displayed by a set of stress vs. 1g(time) curves different from the typical stress relaxation curves. There are two singularities forming a stress plateau on the stress vs.1g(time) curves when precipitates could be observed. Suppose the first one is the start of precipitation (Ps), and the second represcnts the fihish (Pf). As a result Precipitation-Time-Temperature relationship is described as C-shape curves based on two points. This mechanical method is suitable and precise for measuring precipitates in microalloyed steels during hot working.

关键词： stress relaxation precipitation ultra-low carbon bainitic steel (ULCB steel)

Physical Simulation to Determine High TemperatureMechanical Behavior of Continuously Cast Steels

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International Journal of Minerals,Metallurgy and Materials 1997年第1期11卷 30-35页

作者： dang zijiu ZHANG Yan(Staute Key Lab. for Advanced Metals and Materials, USTB, Beijing, 100083, China)

Hot ductility and strength of Continuous casting(CC) steels at elevated temperatures from CC processeswere studied by physical simulation. The method is the hot ductility test. The design of test parameters and datainterpretation are discussed. The results show that the bulging of CC steel slabs which is caused by the mechanismof creep has great influence on the formation of central segregation and internal cracks. Creep tests including staticcreep tests and dynamic creep ones were performed at 1200 and 1300℃. Effects of strain rate and temperature onhot ductility are also discussed and a simple model is presented to explain the interaction between hardening and softening.

关键词： hot ductility crack sensitivity creep strain rate continuous casting

Si C 陶瓷与镍基高温合金的热压反应烧结连接

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稀有金属 1999年第5期23卷 326-330页

作者：段辉平李树杰张永刚刘深张艳党紫九刘登科北京航空航天大学材料科学与工程系北京100083 北京科技大学新金属材料国家重点实验室北京100083 北京东凯永磁材料厂北京100027

采用Ｔｉ Ｎｉ Ａｌ金属复合焊料粉末，利用Ｇｌｅｅｂｌｅ１５００热模拟机以自阻加热方式对镍基高温合金和ＳｉＣ陶瓷进行热压反应烧结连接研究，获得了强度为７０ＭＰａ（ Φ１０ｍｍ ×５０ｍｍ圆棒非标准试... 详细信息

采用Ｔｉ Ｎｉ Ａｌ金属复合焊料粉末，利用Ｇｌｅｅｂｌｅ１５００热模拟机以自阻加热方式对镍基高温合金和ＳｉＣ陶瓷进行热压反应烧结连接研究，获得了强度为７０ＭＰａ（ Φ１０ｍｍ ×５０ｍｍ圆棒非标准试样，四点抗弯强度）的焊接件。微观结构分析表明铝可以通过渗透到陶瓷的非封闭孔隙中或与陶瓷发生界面反应而形成比较牢固的接头。分析了焊缝区焊料中的孔洞对缓解焊接应力的作用。

关键词：陶瓷/金属连接焊接应力

SiC陶瓷/SiC陶瓷及SiC陶瓷/Ni基高温合金SHS焊接中的界面反应及微观结构研究

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硅酸盐学报 1999年第6期27卷 757-762页

作者：李树杰刘深段辉平张永刚吴晨刚党紫九张艳北京航空航天大学材料科学与工程系北京科技大学新金属材料国家重点实验室

采用加压自蔓延高温合成（ＳＨＳ）焊接工艺，连接ＳｉＣ陶瓷／ＳｉＣ陶瓷以及ＳｉＣ陶瓷／Ｎｉ基高温合金．为了得到牢固的界面结合，实验了多种焊料配方．而且基于润湿性、亲合性、ＳＨＳ起爆温度及界面反应的可能性等多方面的考... 详细信息

采用加压自蔓延高温合成（ＳＨＳ）焊接工艺，连接ＳｉＣ陶瓷／ＳｉＣ陶瓷以及ＳｉＣ陶瓷／Ｎｉ基高温合金．为了得到牢固的界面结合，实验了多种焊料配方．而且基于润湿性、亲合性、ＳＨＳ起爆温度及界面反应的可能性等多方面的考虑，设计并实验了多层焊料配方．微观结构显示，液相反应产物对ＳｉＣ陶瓷的润湿性很好．液相能够渗入陶瓷的表面开孔之中，而且界面结合很好．成分分析证实，界面处发生了界面扩散，这有助于界面结合强度的提高．

关键词：界面反应焊接陶瓷金属连接碳化硅陶瓷 SHS