| 摘要 |
PROBLEM TO BE SOLVED: To increase a crystallization rate under a wide thermal spraying condition and to obtain a dense thermal spray repaired layer by containing a specified value in each of SiO2 , Na2 O and the balance inevitable impurities. SOLUTION: The SiO as a main component of a mixture has a component roughly same as a fluorite brick used for a furnace inner face. A content of SiO2 is >=89 wt.% in term of a concentration as oxide. An impurity component of Al2 O3 , etc. is increased in the case that SiO2 content is less than this value, the crystallization rate of a repaired layer immediately after thermal spray is turned to <80%, thereby a crack is likely generated to a joining face between the repaired layer and furnace wall brick. In adding Na2 O and/or Li2 O in addition to SiO2 , crystallizing of the thermal spray repaired layer immediately after thermal spray is promoted, and a dense and strong repaired layer having a compression strength of 200 kgf/cm can be formed. A content of Na2 O is <2.0-4.0 wt.% in term of a concentration of a refractory, a content of Li2 O is >=0.2 wt.% and (Na2 O+Li2 O) is 0.2-4.0 wt.%. |
