The Effect of Service Time on Carbide Volume Fraction and Hardness of Catalyst Tube Materials

International Conference on Design and Application of Engineering Materials in conjunction with Seminar Nasional Metalurgi dan Material XI (SENAMM)

材料科学;金属学

Bastian, Maulidin^1 ; Sugiharto, Eko^1 ; Ardy, Husaini^2

Department of Inspection, PT Pupuk Sriwidjaja, Palembang, Indonesia^1

Department of Material Engineering, Bandung Institute of Technology, Indonesia^2

关键词: Carbide particles;    Carbide precipitate;    Carbide volume fraction;    Catalyst tubes;    Exposure-time;    Image analyzers;    Secondary carbides;    Tube materials;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/547/1/012041/pdf
DOI  :  10.1088/1757-899X/547/1/012041

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The effect of service time on secondary carbides formation in reformer furnace tubes has been studied to obtain a relationship between carbide volume fraction, service time, and hardness. Tube material is Kubota KHR35CT which is part of ASTM A297 HP class. The study was performed by examinations of microstructural evolution and hardness. The microstructures were examined using optical and scanning electron microscopes of the new tube, and the other tubes that had been in service for 17,500; 96,300 and 113,800 hours at 850°C. Carbide volume fraction was measured using image analyzer. Carbide volume fraction of the new tube is 7.72%, and increased to 8.86% after 17,500 hours, 9.54% after 96,300 hours, and 10.95% after 113,800 hours. The increase in carbide volume fraction to 8.86 % did not affect the hardness substantially because the hardness only increases from 191 to 198 BHN. However, increasing exposure times to 96,300 and 113,800 hours decreased the hardness to 170 and 173 BHN respectively. These decreases in hardness may be corresponding to the coarsening and agglomeration of carbide particles due to longer exposure time at 850°C.