THE SECOND PHASE STRENGTHENING AND TOUGHENING EFFECT IN HIGH HARDNESS STEEL WELDS
REN Dengyi; DONG Jian; ZHANG Yuanbin(Colledge of Materials Science and Engineering; Shandong University of Technology; Jinan 250061)
Cite this article:
REN Dengyi; DONG Jian; ZHANG Yuanbin(Colledge of Materials Science and Engineering; Shandong University of Technology; Jinan 250061). THE SECOND PHASE STRENGTHENING AND TOUGHENING EFFECT IN HIGH HARDNESS STEEL WELDS. Acta Metall Sin, 1998, 34(7): 725-730.
Abstract The feature of carbide and microstructure of matrix and their effect on toughness are studied in high carbon welds where Nb, Ti, V, Zr, RE coedest. Test results indicated that the synthetic effect of the multiple strong carbide elements and RE element leads to precipitate fine carbides before solidification of welds. The main mechanism of precipitating carbides from liquid phase is multiple direction precipitating at the same core. The contents of strong carbide elements and carbon element accorded with the fixed-ratio theorem, that made the matrix " carbon poor", and formed low carbon martensite. A weld with high hardness and good thoughness was achieved.