Effect of firing conditions of magnesium carbon brick on brick body properties and microstructure

Effect of firing conditions of magnesium carbon brick on brick body properties and microstructure

Magnesium carbon brick performance due to different firing conditions will be a greater change in the Japanese Kawasaki Harvest company's technical staff in order to study the performance of magnesium carbon brick changes in the mechanism to graphite content of 8% of the low-graphite magnesium brick The effects of thermal shock resistance, matrix structure and composition distribution of magnesium carbon brick were investigated by changing the firing time.

 

The samples were sintered with 8% flake graphite and 92 fused magnesia, plus 1% 99 metal aluminum powder made of magnesium carbon brick, at 1400 ℃ under the conditions of 10h, 30h reduction firing, and then examine the anti- Thermal shock and tissue changes. The thermal shock resistance test is to immerse the test piece in hot water at 1600 ℃ for 90s, then water for 30s, and circulate 3 times to compare the appearance and crack of the test piece. The microstructure of the matrix was observed by FE-SEM and EDS.

 

After observing the section of the sample after thermal shock resistance test, it was found that the samples produced by 30 h reduction were produced, and the cracking was more obvious and the thermal shock resistance was worse. The distribution of aluminum, magnesium, silicon and calcium in the sample matrix sintered at 30 h shows that the magnesium spinel is the original powder, and there are still silicon and calcium in the other parts. This indicates that, due to prolonged firing, the secondary bonding in the matrix, coupled with high impurity content, contribute to the sintering of low melting materials, resulting in increased elastic modulus, thermal shock resistance decreased.