Effect of tempering on microstructure and mechanical properties of a Ta-added 9%Cr steel with high B and low N contents
Abstract
Ta was added to a modified 9%Cr steel with high B and low N content to achieve an optimal dispersion of second phase particles. The effect of tempering on the microstructure and mechanical properties of an Fe-0.1C-9Cr-1.8W-0.6Mo-3Co-Nb-V-0,0013B-0,007N-0,085Ta steel was investigated. Typical martensite lath structure was observed after normalization at 1323 K for 0.5 h. The M23(C,B)6 and complex (Nb,Ta)(C,N) particles formed during tempering at 1023-1053 K. An increase in the hardness after tempering at 1038 K was attributed to the precipitation of the fine (Nb,Ta)(C,N) particles. The impact toughness depended significantly on tempering temperature. The impact toughness increased from 25 to 181 J/cm2 with increasing the tempering temperature from 1038 to 1053 K.
- Publication:
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Materials Science and Engineering Conference Series
- Pub Date:
- April 2019
- DOI:
- 10.1088/1757-899X/525/1/012049
- Bibcode:
- 2019MS&E..525a2049T