Xie Junlin

Optimization Research of Peritectic Steel Mold Flux with Co2O3 Doping

During the solidification process of peritectic steel (PS), the peritectic reaction often causes volume contraction which associated with surface longitudinal cracks, and using mould flux with low heat flux density help for alleviating surface longitudinal cracks. New peritectic steel mold flux with Co2O3 doping reduced the heat flux density, and the optimal content was found to be 2.0 wt %. Furthermore, basicity and Na2O addition were designed, and the minimum heat flux density required basicity of 1.4 and 10.0 wt %. Na2O content. As a result, the optimal peritectic composition was CaO(35.67wt%), SiO2(25.48 wt %),Al2O3(3.7 wt %), MgO(2.53 wt %),Na2O(10 wt %),CaF2(14 wt %),Co2O3(2 wt %).

Effect of the cool system on internal stress of CaO-Al2O3-SiO2 glass-ceramic system

The samples were attained through altering the cooling system of producing glass-ceramics. The X-ray diffraction was used to test the stress value of different samples. The relation of the cooling system and internal stress were also investigated. The experimental results show that the stress of glass-ceramic had a close relation with starting cool temperature. Above 800 °C, glass-ceramic could be accelerated cooling and did not bring stress. Temperature between 500 °C and 800°C was an important temperature range of the formation of stress in glass-ceramic, in which the glass-ceramic stress would change obviously. Cool system was the key on how to control and eliminate internal stress in order to reduce the destroy of materials crated by internal stress. In addition, glass particles size increase, glass-ceramic stress increase in consequent.