检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:沈利民[1] 巩建鸣[1] 唐建群[1] 姜勇[1]
机构地区:[1]南京工业大学机械与动力工程学院,江苏南京210009
出 处:《上海交通大学学报》2010年第5期604-608,共5页Journal of Shanghai Jiaotong University
基 金:国家高技术研究发展计划(863)项目(2007AA04Z407);国家自然科学基金项目(50775107);江苏省"333工程"培养资金项目;南京工业大学博士论文创新基金项目(BSCX200816)
摘 要:以Cr25Ni35Nb和Cr35Ni45Nb合金为炉管材料对象,通过渗碳试验研究了高温(1 000和1 100°C)下2种合金的渗碳动力学规律,采用金相和扫描电子显微镜观察分析其中Fe、Cr、Ni与Nb元素含量和渗碳层变化、组织结构及微区成分转变的情况,并对其抗渗碳能力进行分析.结果表明:Cr35Ni45Nb的抗渗碳能力比Cr25Ni35Nb更强;经2次渗碳后,2种合金试样出现了表面渗碳层剥落的现象,且Cr25Ni35Nb较为严重,并使得裂解炉管结焦而管壁变薄,从而降低了炉管的承载能力和服役寿命;合金的非渗碳层区域析出了大量弥散的碳化物,碳化物的密度随渗碳层与试样表面距离的增加而降低;在1 100°C下,2种合金的骨架状组织形态消失,且晶界处碳化物出现了剥离.Carburization kinetic curve of the two alloys(Cr25Ni35Nb and Cr35Ni45Nb) for ethylene cracking tubes was investigated and analyzed by the carburization experiments at elevated temperature(1 000 and 1 100℃)).Contents of Fe,Cr,Ni and Nb,growth of carburization layer,microstructure and composition of different zones of the two carburized materials were also studied by means of optical microscopy and scanning electron microscopy(SEM).The experimental results show that the carburization resistance of Cr35Ni45Nb alloy is better than that of Cr25Ni35Nb alloy;some locations on the surface of the specimens carburized during two cycling of time spall off and the spallation of Cr25Ni35Nb alloy is much more serious,this indicates that the thickness reduction of the ethylene cracking furnace tube will occur due to high temperature carburization and its strength and service life will be reduced.A mass of dispersive distributed secondary carbides generates in the zone of non-carburization to center zone of coupons,the density of which decreases with the distance increased from surface of coupon;at 1 100℃),the initial bone framework structural morphology of the two materials disappears after carburization and the secondary carbide along the grain boundaries spalls off after carburization.
分 类 号:TG115.2[金属学及工艺—物理冶金]
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:3.148.243.252