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| EFFECT OF RARE EARTH ADDITIONS ON OVERHEATING OF Cr-Ni-Mo STEELS |
| LIU Shumo; CHEN Baoqin: BAI Ying (Nei Monggol Institute of Metallic Materials; Baotou)(Manuscript received 27 December; 1982; revised manuscript 22 January; 1984) |
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Cite this article:
LIU Shumo; CHEN Baoqin: BAI Ying (Nei Monggol Institute of Metallic Materials; Baotou)(Manuscript received 27 December; 1982; revised manuscript 22 January; 1984). EFFECT OF RARE EARTH ADDITIONS ON OVERHEATING OF Cr-Ni-Mo STEELS. Acta Metall Sin, 1984, 20(5): 322-450.
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Abstract The overheating behaviour of several experimental Cr-Ni-Mo steels has been investigated whereby the appearance of the ductile intergranular facets on the fracture surface may be considered as a criterion of overheating. Different overheating phenomena were resulted from that the particles of certain second phase dissolved in the solid solution at high austenization temperature and then reprecipitated along the prior austenite grain boundaries during cooling. It was observed in the Cr-Ni-Mo steels that the intergranular ductile fracture is caused by the reprecipitation of MnS particles in the steel with ordinary S content, and the overheating is also performed by the repreeipitation of AlN or VC particles along the prior austenite grain boundaries in one containing low S. Thus, a proposal seems to be made that the mechanism of overheating of Cr-Ni-Mo steels is related to the solution and reprecipitation of MnS, AlN or VC particles along the prior austenite grain boundaries. The RE additions may act as an inhibitor for the overheating of certain Cr-Ni-Mo steels. If the RE/S ratio reached a critical value, namely about 4, not only the MnS inclusion is completely converted into sulphide and oxysulphide of RE, but also the prior austenite grain is remarkedly refined and their toughness is improved. While the ratio was much greater than 4, the excess RE may be interacted with atoms of C or N.
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Received: 18 May 1984
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1 Ko, T.; Hanson, D., J.Iron Steel Inst., 164 (1950) , 51．
2 Schulz, B. J.; McMahon, C. J., Metall. Trans., 4(1973) , 2485．
3 #12
4 周子年;金嘉陵;徐祖耀,金属热处理学报,2(1981) ,28．
5 Glue, D. R.; Jones, C. H.; Lloyd, H. K. M., Met. Technol., 2(1975) , 416．
6 Waudby, P. E., Int. Metall. Rev., 23 (1978) , 74．4 |
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