|
| Influence of Low Temperature Environment on Mechanical Performance of Three Structural Steels |
| Received:December 08, 2021 Revised:December 20, 2021 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7643/issn.1672-9242.2022.03.018 |
| KeyWord:structural steel low temperature mechanical performance microstructure |
| Author | Institution |
| SU Yan |
Southwest Institute of Technology and Engineering, Chongqing , China |
| SU Hong |
Southwest Institute of Technology and Engineering, Chongqing , China |
| HU Bing-fei |
Southwest Institute of Technology and Engineering, Chongqing , China |
| CHEN Jing-yan |
Southwest Institute of Technology and Engineering, Chongqing , China |
| ZHONG Yong |
Southwest Institute of Technology and Engineering, Chongqing , China |
|
| Hits: |
| Download times: |
| Abstract: |
| This paper aimsto reveal the influence rules of low temperature on the impact toughness and tensile performance of structural steel. Through impact and tensile test, the change rules of such mechanical performance as impact absorbed energy, tensile strength, and the elongation rate after fracture of three structural steels at –70~20 ℃ were studied, the microstructure and the impact fracture morphology features of materials were observed and characterized by the metallographic microscope (OM) and environmental scanning electron microscope (ESEM), and the ductile-brittle transition temperature was measured by impact absorbed energy method. Both 45A and 300M structural steels had body-centered cubic lattice. The change rule of the impact absorbed energy of 45A structural steel was S-shaped with the temperature decreases and produced ductile-brittle transition. Compared with 45A structural steel, the decrease range of impact absorbed energy for 300M structural steel was smaller, and its impact absorbed energy was still up to 75% at –70 ℃. 1Cr18Ni9 had face-centered cubic lattice and gentle change of impact absorbed energy without ductile-brittle transition found at test temperature range. The tensile strength and yield strength of the three structural steels all increased in different degrees with the temperature fell, but the elongation rate and reduction of cross section after fracture decreased. The low temperature brittleness of structural steel has relation with lattice types. The metals with body-centered cubic lattice have cold brittleness, but the metals with face-centered cubic lattice not. The ductile-brittle transition temperatures of 45A and 300M structural steels measured by the impact absorbed energy method are –28 ℃ and < –70 ℃ respectively. |
| Close |
|
|
|