Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel

doi:10.3390/ma11040583

IMR OpenIR

	Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel
	Liu, Hanghang 1,2; Fu, Paixian 1,2; Liu, Hongwei 1,2; Li, Dianzhong 1,2
通讯作者	Fu, Paixian(pxfu@imr.ac.cn) ; Li, Dianzhong(dzli@imr.ac.cn)
	2018-04-01
发表期刊	MATERIALS
ISSN	1996-1944
卷号	11 期号:4 页码:19
摘要	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.
关键词	718H pre-hardened mold steel heat treatments strength-toughness-hardness microstructure
资助者	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
收录类别	SCI
语种	英语
资助项目	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研究方向	Materials Science
WOS类目	Materials Science, Multidisciplinary
WOS记录号	WOS:000434710200125
出版者	MDPI
引用统计	被引频次：12[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/128261
专题	中国科学院金属研究所
通讯作者	Fu, Paixian; Li, Dianzhong
作者单位	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
推荐引用方式 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.