Effect of post weld heat treatment soaking time on microstructure and mechanical properties of TIG welded grade 91 steel

Authors

  • Kasturi Mithun Osmania University
  • Konapalli Saraswathamma Department of Mechanical Engineering, University College of Engineering (A)
  • Dhanesh Kant Verma Welding Research Institute, BHEL, Tiruchirappalli

Keywords:

Modified 9Cr-1Mo steel, TIG, PWHT, Microstructure, Hardness, Impact Toughness

Abstract

Development of new alloy materials is in progress to improve thermal efficiency of supercritical boilers. One of such material is modified 9Cr-1Mo (Grade 91) martensitic alloy steel referred as T/P91. This material is extensively used in high temperature applications such as fabrication of superheater, reheater and economizer sections of a boiler. The present study is made to find the effect of post weld heat treatment (PWHT) soaking time on microstructure and mechanical properties of TIG welded ASTM A213 Grade 91 steel plate. Experiments were conducted for PWHT at 760°C for different soaking time such as 2, 4 and 6 hours to get the desired mechanical properties. The investigated results suggest that PWHT of 2 hours at 760°C is optimal to regain the strength of Grade 91 steel after welding.

Downloads

Download data is not yet available.

References

T. Shrestha, S. F. Alsagabi, I. Charit, G. P. Potirniche, and M. V. Glazoff, "Effect of heat treatment on microstructure and hardness of rade 91 steel," Metals, vol. 5, no. 1, pp. 131- 149, 2015.

B. Silwal, L. Li, A. Deceuster, and B. Griffiths, "Effect of postweld heat treatment on the toughness of heat-affected zone for grade 91 steel," Welding Journal, vol. 92, no. 3, pp. 80S-87S, 2013.

C. Pandey and M. Mahapatra, "Effect of heat treatment on microstructure and hot impact toughness of various zones of P91 welded pipes," Journal of Materials Engineering and Performance, vol. 25, no. 6, pp. 2195-2210, 2016.

N. Tammasophon, W. Homhrajai, and G. Lothongkum, "Effect of postweld heat treatment on microstructures and hardness of TIG weldment between P22 and P91 steels with Inconel 625 filler metal," Journal of Metals, Materials and Minerals, vol. 21, no. 1, pp. 93-99, 2011.

B. Arivazhagan and M. Vasudevan, "A study of microstructure and mechanical properties of grade 91 steel A-TIG weld joint," Journal of Materials Engineering and Performance, vol. 22, no. 12, pp. 3708-3716, 2013.

Vishal Singh, V. Sudharsanam, and M. Madhu, "Evaluation of fracture toughness of modified 9Cr-1Mo steel at various PWHT cycles," WRI Journal, vol. 37, no. 3, p. 7, 2016.

G. Taniguchi and K. Yamashita, "Effects of post weld heat treatment (PWHT) temperature on mechanical properties of weld metals for high-Cr ferritic heat-resistant steel," Kobelco Technology Review, vol. 32, pp. 33-39, 2013.

M. Abd El-Rahman Abd El-Salam, I. ElMahallawi, and M. R. El-Koussy, "Influence of heat input and post-weld heat treatment on boiler steel P91 (9Cr–1Mo–V–Nb) weld joints Part 2 – Mechanical properties," International Heat Treatment and Surface Engineering, vol. 7, no. 1, pp. 32-37, 2013.

J. Parker and K. Coleman, "EPRI guidelines for fabrication of components manufactured from Grade 91 steel," in ASME 2012 Pressure Vessels and Piping Conference, 2012, pp. 187-195: American Society of Mechanical Engineers.

V. Sudharsanam. M. Madhu, and Vishal Singh, "Evaluation of fracture toughness of modified 9Cr-1Mo steel at various PWHT cycles," WRI Journal, vol. 37, no. 3, pp. 05- 11, 2016.

A. Sharma, D. K. Verma, and S. Kumaran, "Effect of post weld heat treatment on microstructure and mechanical properties of Hot Wire GTA welded joints of SA213 T91 steel," Materials Today: Proceedings, vol. 5, no. 2, pp. 8049-8056, 2018.

A. Boiler and P. V. Committee, ASME Boiler and Pressure Vessel Code: Ferrous Material Specifications. Part A. American Society of Mechanical Engineers.

A. A5.28/A5.28M, "Specification for lowalloy steel electrodes and rods for gas shielded arc welding," vol. 3rd edition, p. 3, 2015.

B. H. E. L. and I. I. o. Metals, "A International Workshop on Fabrication & Processing of Grade 91 Material," p. 7 &73, 2015.

B. Arivazhagan and M. Kamaraj, "A study on influence of δ-ferrite phase on toughness of P91 steel welds,," Steel GRIPS, vol. 18, no. 2, p. 6, 2013.

M. Syed Zameeruddin, Sandhyarani Biswa, and Maridurai T, "Mechanical properties and fracture characteristics of ASTM A335 P91 steel used in boiler materials," International Journal of ChemTech Research, vol. 07, no. 02, p. 7, 2015.

A. Ghatak and P. Robi, "Modification of Larson–Miller parameter technique for predicting creep life of materials," Transactions of the Indian Institute of Metals, vol. 69, no. 2, pp. 579-583, 2016.

C. Pandey and M. M. Mahapatra, "Effect of heat treatment on microstructure and hot impact toughness of various zones of P91 welded pipes," Journal of Materials Engineering and Performance, vol. 25, no. 6, pp. 2195-2210, 2016.

A. Roy, P. Kumar, and D. Maitra, "The effect of silicon content on impact toughness of T91 grade steels," Journal of Materials Engineering and Performance, vol. 18, no. 2, pp. 205-210, 2009.

K. S. Chandravathi, K. Laha, K. Bhanu Sankara Rao, and S. L. Mannan, "Microstructure and tensile properties of modified 9Cr–1Mo steel (grade 91)," Materials Science and Technology, vol. 17, no. 5, pp. 559-565, 2001.

J. Oñoro, "Martensite microstructure of 9– 12%Cr steels weld metals," Journal of Materials Processing Technology, vol. 180, no. 1, pp. 137-142, 2006.

Downloads

Published

2019-06-29

How to Cite

[1]
K. . Mithun, K. . Saraswathamma, and D. K. . Verma, “Effect of post weld heat treatment soaking time on microstructure and mechanical properties of TIG welded grade 91 steel”, J Met Mater Miner, vol. 29, no. 2, Jun. 2019.

Issue

Section

Original Research Articles