Thermodynamic Analysis of Precipitation of La-O-S-As Inclusions in Steel
The formation of RE-O-S-As inclusions and corresponding arsenic content of equilibrium solid solubility were two core issues concerned when adding rare earth to restrain the harm of residual arsenic in steel. In this paper, some databases of rare earth inclusion were supplied. The influence of different La content on the formation of inclusions during solidification of As-bearing steel was calculated. The results showed that with the increase of rare earth content, the original inclusions MnS, Al6Si2O13 and Mn2Al4Si5O18 in steel were replaced by La2Al2O6, La2O2S, La2S3, La3S4 and LaS. The formation mechanism of As-bearing rare earth inclusions was analysed under the condition of excess rare earth, and the results showed that the As-bearing rare earth inclusions were formed during the solidification process due to enrichment of solidification frontier elements.
KeywordsResidual elements Inclusions Rare earths Arsenic
This research is financially supported by National Natural Science Foundation of China (Grant No. 51704051), Chongqing Postdoctoral Funds (Grant No. Xm2017192) and the Fundamental Research Funds for the Central Universities (Grant No. 106112015CDJXY130009).
- 3.Noboru H, Hidemi K, Teruo T (1971) Method for removing arsenic from metals or alloys: U.S. 3, 622, 302[P], 23 Nov 1971Google Scholar
- 7.Wang L, Du T (1986) Study on the balance of [La]-[S]-[O] in molten iron. Rare Earth 2:25–32Google Scholar
- 8.Li DZ, Wang ZY (1980) Some regularities of formation and change of rare earth inclusions in steel. Iron 8:34–39Google Scholar