| Title |
Effects of Tempering Temperature and Heat-Treatment Path on the Microstructural and Mechanical Properties of ASTM Gr.92 Steel |
| Authors |
김연근(Yeon Keun Kim); 한창희(Chang Hee Han); 백종혁(Jong Hyuk Baek); 김성호(Sung Ho Kim); 이찬복(Chan Bock Lee); 홍순익(Sun Ig Hong) |
| DOI |
https://doi.org/10.3365/KJMM.2010.48.01.039 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
sodium-cooled; fast reactor; SFR; fuel cladding; ferritic/matensitic steel; heat-treatment; microstructures; tensile properties |
| Abstract |
In order to investigate the effects of tempering temperature and heat-treatment path on the microstructural and mechanical properties of ASTM Gr.92 steels, foul samples with different tempering temperatures and heat-treatment paths were prepared. Three experimental steels showed tempered martensitic microstructures. but the sample tempered at 8l0℃ was presumed to retain partially untempered martensitic microstructures due to a lower α+γ phase regime. M23C6. V(C,N), and Nb(C.N) precipitates were observed in all samples. In addition, Cr2N was observed to be precipitated finely and uniformly by isothermal heat-treatment. The lath width and precipitate size increased with an increase of the tempering temperature. In particular, the lath width and precipitate size in the isothermal heat-treated samples were much smaller than those of the tempered-only specimens. Because of a fine and uniform precipitate, a reduction of lath width would enhance precipitation hardening, and it was shown that mechanical propertiesincluding the hardness and tensile properties of the steels were improved by isothermal heat-treatment. |