Effect of Isothermal Ageing on Microstructure and Mechanical Behavior of 0.5Cr-0.5Mo-0.2V Low Alloy Steel

Forfattere

  • Ranjana Kumari
  • Goutam Das CSIR-National Metallurgical Laboratory, Jamshedpur, Jharkhand, India

Nøgleord:

Spheroidisation, carbides, secondary precipitation, ageing

Resumé

Cr-Mo-V based low alloy steels are widely used in thermal power plants because of theirability to withstand elevated temperature and high pressure under continuous operation. Withferrite-pearlite and/or ferrite-bainite microstructures, these steels find their applications inboiler tubes, pressure vessels and steam turbines. Being cost effective is one of the importantfactors, which draws attention of many industrialists towards low alloyed steels over highlyalloyed steels with austenitic matrix. In this work, the microstructure and mechanicalproperties degradation of low alloy steel sample were analyzed. Investigated material was inservice for 35 years. During its service life, it was exposed to high temperature and pressureresulting in properties to undergo changes. To figure out these evident changes, sample wassolutionized and tempered for different ageing times under laboratory conditions. Changes inthe morphology of the steel microstructure such as pearlite decomposition, carbideprecipitation and spheroidisation etc. could be observed. Due to its coherent relation withmicrostructure, mechanical properties were also found to have undergone variations. In orderto investigate the behavior of this steel after its exposition to different environments, hardnessand tensile tests were conducted. Microstructural evolution of the sample was observed usingSEM. TEM analysis was done to figure out the nature of carbides formed duringexperimentation. Experiments revealed the improvement in mechanical properties of the steelin the initial hours of its service due to the phenomenon of secondary precipitation. But, afterreaching its peak condition (over-ageing) deterioration in the properties started.Cite this ArticleRanjana Kumari, Goutam Das. Effect ofIsothermal Ageing on Microstructure andMechanical Behavior of 0.5Cr-0.5Mo-0.2V Low Alloy Steel. Journal ofMaterials & Metallurgical Engineering. 2015. 5(3): 7–14p.

Downloads

Publiceret

2015-11-16

Nummer

Årg. 5 Nr. 3 (2015)

Sektion

Research Articles

Licens

Declaration and Copyright Transfer Form

(to be completed by authors)

 

I/ We, the undersigned author(s) of the submitted manuscript, hereby declare, that the above manuscript which is submitted for publication in the STM Journals(s), is not published already in part or whole (except in the form of abstract) in any journal or magazine for private or public circulation, and, is not under consideration of publication elsewhere.

·         I/We will not withdraw the manuscript after 1 week of submission as I have read the Author Guidelines and will adhere to the guidelines.

·         I/We Author(s ) have niether given nor will give this manuscript elsewhere for publishing after submitting in STM Journal(s).

·         I/ We have read the original version of the manuscript and am/ are responsible for the thought contents embodied in it. The work dealt in the manuscript is my/ our own, and my/ our individual contribution to this work is significant enough to qualify for authorship.

·          I/We also agree to the authorship of the article in the following order:

Author’s name                                    

 

1. ________________

2. ________________

3. ________________

4. _______________

 

We  Author(s) tick this box and would request you to consider it as our signature as we agree to the terms of this Copyright Notice, which will apply to this submission if and when it is published by this journal.