共查询到18条相似文献,搜索用时 171 毫秒
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热轧高强度重轨钢的珠光体团块尺寸和层片间距以及钢轨表面脱碳层深度对钢轨在磨损和滚动接触疲劳条件下的使用性能具有重要影响.在邯钢采用SMS Meer万能机组轧制100 m定尺超长轨的设备工艺条件下,为了制定合理的U71Mn钢坯加热制度、细化珠光体组织和控制表面脱碳层深度,在实验室进行了加热工艺参数对U71Mn钢轨钢奥氏体晶粒尺寸和脱碳层深度的影响规律的实验研究.实验结果表明:U71Mn钢坯在加热温度升至1050~1150℃而均热时间为35min时,奥氏体晶粒尺寸和脱碳层深度开始有明显增长的趋势,奥氏体晶粒尺寸在120~160μm但比较均匀,有效脱碳层深度增加到0.42~0.61mm;当加热温度升高到1200~1250℃时,奥氏体晶粒尺寸超过180μm并随着保温时间的延长出现显著的不均匀长大,有效脱碳层深度增加到0.81~0.90mm.根据上述实验数据,对邯钢U71Mn钢加热工艺规程提出了优化参数,使热轧钢轨的珠光体组织、力学性能和脱碳层深度满足了国家标准和铁道部标准的要求. 相似文献
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XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research Academia Sinica Shenyang ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron Steel Research Ministry of Metallurgical Industry Panzhihua China associate professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1993,6(6):415-419
The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivityas well as the hydrogen distribution in the cross section of blooms with stack cooling were stu-died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible,the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)×10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which ishelpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron andSteel Company. 相似文献
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采用 Gleeble 热模拟试验技术,确定贝氏体辙叉钢与 U71Mn 钢轨钢电阻对焊时热影响区的温度场分布及顶锻压力工艺参数;利用该参数在小型闪光焊机上进行小试件焊接试验,确定闪光焊接试验参数;利用 Gaas-100 次级直流闪光焊机对贝氏体钢辙叉与 U71Mn 钢轨进行整轨实际焊接,分析焊接接头拉伸、冲击、硬度分布等力学性能以及其组织结构.结果表明,贝氏体辙叉与钢轨闪光焊接的最佳顶锻压力为 30 MPa 左右,其焊接热影响区很小,焊接接头各项力学性能均达到了铁道部有关标准要求,贝氏体钢辙叉与 U71Mn 钢轨采用闪光对焊直接焊接是可行的.Abstract: The temperature field distribution of heat-affected zone (HAZ) in weld joints of bainite steel and U71Mn steel and the technical parameters of upset pressure of flash butt welding were determined by using the Gleeble thermal simulation test technology.After some small specimens of bainitic crossing steel and U71Mn rail steel were welded with a miniature flash butt welder by using the results of the parameters to determine the technical parameters of flash butt welding experiment, bainitic steel crossing and U71Mn steel rail were practically welded with Gaas-100 direct current flash butt welder. The mechanical properties, including tensile toughness, impact test and hardness,and the microstructure of welded joints were analyzed. The results show that the best upset pressure of flash butt welding is about 30 MPa, which the HAZ is very small, and the mechanical properties of the welded joint comes up to the standard of the Ministry of Railway. The welding bainitic crossing steel and U71Mn rail steel by flash butt welding is completely feasible. 相似文献
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为使高速及重载道岔AT钢尖轨跟端锻造热处理后组织与性能满足最新标准和线路使用要求,采用自主研发钢轨全断面感应加热+喷风冷却生产线,对高速及重载道岔60AT2-U71MnG及60AT1-U75V在线热处理钢轨压型跟端进行了热处理工艺试验,观察了硬化层的显微组织,检测了钢轨化学成分、硬化层深度、表面硬度、断面硬度、抗拉强度... 相似文献
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U71Mn钢轨与船舶甲板(A3板)之间的物理性能与化学成分差距很大,U71Mn的碳当量很高,其可焊性很差,当U71Mn与船舶甲板焊接时由于钢轨和船舶甲板的线膨胀系数差距很大,在焊接应力的作用下,其角焊缝极易出现裂纹.通过对钢轨与船舶甲板角焊缝工艺的研究,解决了U71Mn钢轨与船舶甲板相焊时,角焊缝易出现裂纹的问题. 相似文献
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青藏铁路等低温地区铁路的建设与维护,对钢轨铝热焊接接头的低温力学性能的研究提出了迫切的要求.通过U71Mn和U75V两种钢轨的铝热焊接接头低温拉伸试验,得到了两种钢轨铝热焊接接头各温度下的强度与塑性指标,分析了各指标随温度的变化规律.结果表明,两种钢轨铝热焊接接头的规定非比例延伸强度均随温度的降低而提高,而抗拉强度均随温度的降低而降低;两者的屈强比均随温度的降低而升高,断后伸长率和断面收缩率均随温度的降低而减小,塑性变差,低温冷脆倾向增加;U71Mn钢轨接头的断后伸长率和断面收缩率均较U75V钢轨接头大,塑性更好.在寒冷地区的铁路建设中,宜优先选用U71Mn钢轨及相应的铝热焊接材料. 相似文献