IJE TRANSACTIONS B: Applications Vol. 17, No. 2 (July 2004) 183-190   

downloaded Downloaded: 719   viewed Viewed: 3469

S. A. Jenabali. Jahromi and M. NaghiKhani

Department of Materials Science and Engineering, School of Engineering
Shiraz University, Shiraz, Iran, Jahromi@shirazu.ac.ir
( Received: August 09, 2003 – Accepted in Revised Form: June 10, 2004 )

Abstract    Assessment of creep damage and residual creep life of a cast HP 40 Nb Mod. Reformer tube was performed, wherein the experimental Larson–Miller diagram and area fraction of creep voids were adopted. The state of damage of the tube in service was metallographically analyzed by using light and electron microscopy. Samples from the serviced reformer furnace tube were cut and prepared for void examination and creep test at 940ºC-1000ºC under 20-30 MPa stress. Microstructural examination was carried out with an Scanning electron microscope with secondary and backscattered electron detectors. Inter-granular voids in the microstructure of the worked tube as a result of a creep phenomenon are ranked relating to the remaining life.


Keywords    Creep Life Assessment, Ammonia Plant, HP40 Nb Modified Steel Tube



1. Viswanathan, R. and Foulds, J., "Accelerated Stress Rupture Testing For creep Life Prediction – Its Value and Limitation", Journal of Pressure Vessel Technology, Vol. 120, (May 1998), 105-115.

2. Bhaumik, S. K., Rangaraju, R. and Parameswara, M. A., "Failure of Reformer Tube of an Ammonia Plant", Engineering Failure Analysis, 9, (2002), 553-561.

3. Blair and Stevens, T. L. (Eds.), “Heat-Resistant High Alloy Steels, Steel Castings Handbook”, 6th Ed., Steel Founders Society of America and ASM International, (1995), 22(1)-22(13).

4. Paralloy, H39WM, “High Strength, High Temperature Alloy for Steam Cracking Furnaces and Steam Reformer Furnaces”, Paralloy House, Nuffield Raod, Billingham, Cleveland, England TS23 4DA.

5. Schillmoller, C. M., "Hp-Mod.ified Furnace Tube for Steam Reforms and Steam Crackers", NiDI Technical Series, No. 10058.

6. ASM Handbook, “Heat-Resistant Materials”, Materials Park, ASM International, (1999).

7. Jahromi, S. A. J. and NaghiKhani, M., “Failure Analysis of HP40 -Nb Modified Primary Reformer Tube of Ammonia Plant”, Iranian Journal of Science and Technology, Transactions B, Vol. 28, Bo. B2, (April2004), 269-271.

8. Viswanathan, R., “Damage Mechanisms and Life Assessment of High-Temperature Components”, Metals Park, Ohio 44073, ASM, (1995).

9. ASM, Handbook, "Heat Resistant Materials", Metals Park, Ohio 44073, ASM, International, (1999).

10. Komei Kasahara, “A Method for Estimating Residual Creep Lives of Cast HK-40 Reformer Tubings”, TokyoGas Company Ltd., R&D Institute, 1-16 Shibaura, Tokyo, Japan C 235/ 89, C Mech. E., (1980), 249-264.

11. Da Silveira, T. L. and Lemag, I., “Damage Assessment and Management in Reformer Furnaces” Journal of Pressure Vessel Technology Now, Vol. 119, (1997), 423-427.

12. Gong Jian Shan-Tung Tu and Kee Bong Yoon, “Damage Assessment and Maintenance Strategy of Hydrogen Reformer Furnace Tubes”, Engineering Failure Analysis, 6 (1999), 143-153.

13. Goerge Ellwood Dieter, "Mechanical Metallurgy", 3Ed., New York, Mac-Graw Hill Company, (1986).

14. C. W, Thomas, Stevens, K. J. and Ryan, M. J. “Microstructure and Properties of Alloy HP50NbComparison of As Cast and Service Exposed Materials”, Materials Science and Technology, Vol. 12, (1996), 469-475.

15. May, I, Le., Da Silveira, T. L. and Vianna, C. H.,“Criteria for the Evaluation of Damage and Remains Lifein Reformer Furnace Tubes", Int. J. Pres. Ves, 8 Piping 66, (1996), 233-241.

International Journal of Engineering
E-mail: office@ije.ir
Web Site: http://www.ije.ir