|
|
MECHANISM OF CRACK NUCLEATION AND PROPA- GATION OF FERRITE DUCTILE IRON DURING IMPACT FRACTURE UNDER LOW TEMPERATURES |
Xinning ZHANG,Yingdong QU,Rongde LI,Junhua YOU |
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 |
|
Cite this article:
Xinning ZHANG,Yingdong QU,Rongde LI,Junhua YOU. MECHANISM OF CRACK NUCLEATION AND PROPA- GATION OF FERRITE DUCTILE IRON DURING IMPACT FRACTURE UNDER LOW TEMPERATURES. Acta Metall Sin, 2015, 51(11): 1333-1340.
|
Abstract Due to its excellent ductility and moderate strength, QT400-18L ferrite ductile iron has been widely used in producing core components of wind power equipment such as the hub of a wind turbine. Most of the researches have focused on the exploration of mechanical properties at low temperature, but none of them give the explanation on microcosmic mechanism of ductile iron during low temperature impact and the mechanism of crack nucleation and propagation of ferrite ductile iron during impact fracture has not been analyzed. In this work, the impact toughness of QT400-18L ferrite ductile iron was measured by V-notch Charpy impact test at different temperatures, the influence of low temperature impact toughness and the fracture behavior of ferrite ductile iron were discussed. The results show that the cleavage fracture resistance of QT400-18L ferrite ductile iron is reduced with the decrease of impact temperatures. Above ductile-brittle transition temperature (DBTT), most of the total fracture energies are expended during the crack propagation process. Below DBTT, both crack initiation energy and crack propagation energy decrease obviously. By using in situ fracture metallographic observation method, crack initiation and propagation of QT400-18L ferrite ductile iron under different temperatures were analyzed. Above DBTT, graphite nodules play the role of crack blunting and reducing crack propagation rate; in DBTT range, the fracture morphology shows mixed fracture with cleavage and dimples, which are related to graphite nodules; below DBTT, deformation twins lead to the nucleation of microcrack and result in cleavage fracture, the deformation twinning could possibly play a significant role in the ductile to brittle transition of QT400-18L ferrite ductile iron.
|
|
Fund: Supported by National Natural Science Foundation of China (No.51274142), Natural Science Foundation of Liaoning Province (No.2014028015) and Program of Bureau of Shenyang Science and Technology (No.F15-199-1-15) |
[1] | Qi Z C, Bo K W. China Foundry, 2008; 5(2): 82 | [2] | Labrecque C, Gagne M. Can Met Quart, 1998; 37: 343 | [3] | Hau?ild P, Nedbal I, Berdin C. Mater Sci Eng, 2002; A335: 164 | [4] | Sertucha J, Lacaze J, Serrallach J. Mater?Sci?Technol, 2012; 28: 184 | [5] | Wei B Q, Liang J, Gao Z D, Wu D H. J Tsinghua Uni (Sci Technol), 1996; 26: 56 (魏秉庆, 梁 吉, 高志栋, 吴德海. 清华大学报(自然科学版), 1996; 26: 56) | [6] | Dai P Q, He Z R, Mao Z Y. J Iron Steel Res, 2001; 13(6): 47 (戴品强, 何则荣, 毛志远. 钢铁研究学报, 2001; 13(6): 47) | [7] | Dai P Q. PhD Dissertation, Zhejiang University, Hangzhou, 2002 (戴品强. 浙江大学博士学位论文, 杭州, 2002) | [8] | Dai P Q, He Z R, Zheng C M, Mao Z Y. Mater Sci Eng, 2001; A42: 531 | [9] | Ibrahim O H, Elshazly E S. J Mater Eng Perform, 2013; 22: 584 | [10] | Tanguy B, Besson J, Piques R. Eng Fract Mech, 2005; 72: 413 | [11] | Toshiro K, Isamu Y, Mitsuo N. Eng Fract Mech, 1986; 24: 773 | [12] | Marushchak P O, Bishchak R T, Gliha B. J Mater Sci, 2011; 46: 568 | [13] | Tang Z T. Phys Exam Testing, 2004; (4): 5 (唐振廷. 物理测试, 2004; (4): 5) | [14] | Masaki T, Tatsuro O, Toshihiro T, Kenji H. ISIJ Int, 2012; 52: 915 | [15] | Christian J W, Mahajan S. Prog Mater Sci, 1995; 39: 1 | [16] | Pineau A. Int J Fract, 2006; 138: 139 | [17] | Ratto P J, Ansaldi A F, Fierro V E, Alvarez H N, Sikora J A. ISIJ Int, 2001; 41: 372 | [18] | Zenjiro Y, Yoichi K, Ken'ichi S, Hideharu M, Toshiki Y. Mater Trans, 2006; 47: 82 | [19] | Brooks C R,translated by Xie F J,Sun J X. Failure Analysis of Engineering Material. Beijing: Machine Industry Press, 2003: 256 (Brooks C R著,谢斐娟,孙家骧译. 工程材料的失效分析. 北京: 机械工业出版社, 2003: 256) | [20] | Junaidi S, Toshihiro T, Setsuo T. ISIJ Int, 2003; 43: 1100 | [21] | Ni C H, Wang F C, Xu Q. J Beijing Inst Technol, 2011; 8: 984 (倪川皓, 王富耻, 徐 强. 北京理工大学学报, 2011; 8: 984) | [22] | Smida T, Bosansky J. Mater Sci Eng, 2000; A287: 107 | [23] | Myagchilov S, Dawson P R. Mater Sci Eng, 1999; A7: 975 | [24] | Li J, Zhong Q P. Ordnance Mater Sci Mech, 1984; 2(8): 64 (李 洁, 钟群鹏. 兵器材料与力学, 1984; 2(8): 64) |
|
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|