|
|
|
| AN IN S ITU STUDY OF CRACK NUCLEATION AND PROPAGATION IN PEARLITE DURING DEFORMATION |
| Xu Yongbo; Liu Minzhi (Institute of Metal Research; Academia Sinica; Shenyang) |
|
Cite this article:
Xu Yongbo; Liu Minzhi (Institute of Metal Research; Academia Sinica; Shenyang). AN IN S ITU STUDY OF CRACK NUCLEATION AND PROPAGATION IN PEARLITE DURING DEFORMATION. Acta Metall Sin, 1982, 18(1): 58-128.
|
|
|
Abstract The microprocess of deformation and fracture of structural steels containing 0.15, 0.45 and 0.79％ C respectively have been examined by tensile testing on SEM. For the specimens of steels 15 and 45, it was observed that the deformation is mainly undergone in proeutectoid ferrite, as well as shear, multipe-slip and colony rotation exhibited in pearlite. The crack is almost entirely nucleated at the interface of the inclusion/matrix or pearlite/ferrite. The fracture mode is ductile. In specimens of eutectoid steel T8, the cementite lamellae may be plastically deformed to some extent, and its tendency increases with the decrease of interlamellar spacing. When the microstructure contains fine pearlite, a uniform strain distribution, a wider strain range as well as slip and bending phenomena of cementite lamellae have been observed. Fracture is of ductile characteristic. On the contrary, coarse pearlite deformed more inhomogeneously with localized strain in intense shear bands. The crack nucleation is initiated by cracking of cementite lamellae along shear bands. The fracture is brittle. The cracking phenomenon along shear deformation bands in eementite lamellae has been discussed by the authors referring to the model of pile-up of dislocations.
|
|
Received: 18 January 1982
|
1 Miller, L. E.; Smith, G. C., J. Iron Steel Inst., 208 (1970) , 998．
2 Burns, K. W.; Picketing, F. B., J. Iron Steel Inst., 202 (1964) , 899．
3 Gurland, J., Acta Metall., 20 (1972) , 735．
4 Lindborg, U., ASM Trans, Q., 61 (1968) , 500．
5 Rosenfleld, A. R.; Hahn, G. T.; Embury, J. D., Metall. Trans., 3 (1972) , 2797．
6 徐永波;刘民治;朱桂秋;于章,金属学报,16(1980) ,486．
7 Danko, J. C.; Stout, R. D., Weld., J., 34 (1955) , 113-s.
8 Porter, D. A.; Easterling, K. E.; Smith, G. D. W., Acta Metall. 26 (1978) , 1405．
9 徐永波;刘民治;李恒武;苏会和;朱桂秋,金属学报,15(1979) ,367．
10;徐永波;刘民治;于章;朱桂秋,金属学报,17(1981) ,102．
11 徐永波;穆在勤;刘民治;杨淑华,科学通报(待发表).
12 Lai, Z. H.; Wie, H. Y.; Liu, S. F.; Li R. C., Proc. Fourth Int. Conf. on Titumium, Vol. 3, 1980, Eds. Kimura, H.; Izumi, O., Metall. Soc. AIME, New York, p. 1757．
13 Koss, R. A.; Chan, K. S., Acta Metall., 28 (1980) , 1245．
14 徐永波;徐振声;张天宜;刘民治;庄育智;待发表.
15 Smith, E.; Barnby, J. T., Met. Sci. J., 1 (1967) , 56．I |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
