| Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel | |
| Liu, Hanghang1,2; Fu, Paixian1,2; Liu, Hongwei1,2; Li, Dianzhong1,2 | |
| Corresponding Author | Fu, Paixian(pxfu@imr.ac.cn) ; Li, Dianzhong(dzli@imr.ac.cn) |
| 2018-04-01 | |
| Source Publication | MATERIALS
 |
| ISSN | 1996-1944 |
| Volume | 11Issue:4Pages:19 |
| Abstract | The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron back-scattered diffraction (EBSD). The mechanical properties were compared by tensile, Charpy U-notch impact and hardness uniformity tests at room temperature. The results showed that the test steels after normalizing-quenching-tempering (N-QT) possessed the best strength-toughness combination and hardness uniformity compared with the conventional quenched-tempered (QT) steel. In addition, the test steel after austempering-tempering (A-T) demonstrated the worse hardness uniformity and lower yield strength while possessing relatively higher elongation (17%) compared with the samples after N-QT (14.5%) treatments. The better ductility of A-T steel mainly depended on the amount and morphology of retained austenite and thermal/deformation-induced twined martensite. This work elucidates the mechanisms of microstructure evolution during heat treatments and will highly improve the strength-toughness-hardness trade-off in large cross-section steels. |
| Keyword | 718H pre-hardened mold steel heat treatments strength-toughness-hardness microstructure |
| Funding Organization | National Key Research and Development Program of China ; Cooperation Program of Hubei province ; Chinese Academy of Sciences (The Research and Development of Key Technologies for Special Steel of Homogeneous High Performance) |
| DOI | 10.3390/ma11040583 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Key Research and Development Program of China[2016YFB0300401] ; Cooperation Program of Hubei province ; Chinese Academy of Sciences (The Research and Development of Key Technologies for Special Steel of Homogeneous High Performance) |
| WOS Research Area | Materials Science |
| WOS Subject | Materials Science, Multidisciplinary |
| WOS ID | WOS:000434710200125 |
| Publisher | MDPI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/128257 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Fu, Paixian; Li, Dianzhong |
| Affiliation | 1.Chinese Acad Sci, Inst Met Res, 72 Wenhua Rd, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, 72 Wenhua Rd, Shenyang 110016, Peoples R China |
| Recommended Citation GB/T 7714 | Liu, Hanghang,Fu, Paixian,Liu, Hongwei,et al. Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel[J]. MATERIALS,2018,11(4):19. |
| APA | Liu, Hanghang,Fu, Paixian,Liu, Hongwei,&Li, Dianzhong.(2018).Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel.MATERIALS,11(4),19. |
| MLA | Liu, Hanghang,et al."Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel".MATERIALS 11.4(2018):19. |
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