Application of MgO-Cr2O3 brick compsoed of MgO>72%,Cr2O3>14.8%-16.69%,with porosity 13%-4%,compressive strength 33.0-43.8 MPa ,flexing strength 11.9-16.5 MPa and refractoriness under load≥1750℃ in a assembled ...Application of MgO-Cr2O3 brick compsoed of MgO>72%,Cr2O3>14.8%-16.69%,with porosity 13%-4%,compressive strength 33.0-43.8 MPa ,flexing strength 11.9-16.5 MPa and refractoriness under load≥1750℃ in a assembled snorkel of 300t RH funace in Baoshan Iron & Stel Company (Baosteel) showed good results of average service life of 106.6 heats maximum 119 heats.Petrologi-cal analysis and visual examination were also done on the residual brick to investigate thewear mechanism.展开更多
This essay analyses three different kinds of insulating boards for used tundish by OM,EDAX and XRD,aiming at disclosing its mi-crostuructue,and tryin to find out its wear mechanism. The SiO2 insulating board has the t...This essay analyses three different kinds of insulating boards for used tundish by OM,EDAX and XRD,aiming at disclosing its mi-crostuructue,and tryin to find out its wear mechanism. The SiO2 insulating board has the trans-formation from quartz to α-cristoballite to some extent.It forms a large quantity of glass phases while reacting with slags,which belongs to corrosion wear.The MgO insulating board belongs to both spaling and corrosion wear,for it forms MA,C3MS2, and melilite minerals while reacting with slags,When M2S board reacts with slags,[Fe] of the unchanged 2[Mg,Fe]O·SiO2s.s will be replaced by [Mn] of the slag phases to form 2[Mg,Mn,Fe]O·SiO2.s,leaching Fe ,Which belongs to both spalling and corrosion wear,This essay also makes fur-ther discussion about the three diferent refrac-tory effects on steel quality.展开更多
The application results of semi-rebonded magnesite-chrome bricks at RH lowe vessel of NKK Corporation Keihin Works have been analysed,The results indicate that the main reasons that cause the damage of the refactory b...The application results of semi-rebonded magnesite-chrome bricks at RH lowe vessel of NKK Corporation Keihin Works have been analysed,The results indicate that the main reasons that cause the damage of the refactory brcks include:chemical attack of slage to the semi-rebonded magnesite-chrome bricks;pene-tration of molten stel,slag into the bricks;and therma spalling due to temperature fluctua-tion during steel making operation.The results of multiple effection of these factors lead to alternative action of erosion(chemical attack and penetration)and spalling(thermal spalling and structure peeling) resulting in the damage of the brik ,In order to improve the performance of the bricks ,it is necessary to promote the resistance to erosion and thermal shock resistance as well as to keep the accurate dimensions of the brick,The measures of improvement of resistance to erosion of magne-site-chrome bricks taken by the researches mainly include:lowering the contents of impu-rities in the bricks(mainly including SiO2,CaO,and next Fe2O3 and Al2O3);promoting the extent of direct bond of the brick;forming a large amount of magnesia-chrome composite spinel well-distributed in the bricks through adding a large amount of synthesized materi-als;enhancing the resistance to erosion by adding a little amount of high-effective additives,Improvement of thermal shock resistance of the bricks is mainly through introducing some additive to make a certain amount of mi-cro-cracks occur in the brick so as to obtain an effect of increasing toughnes or through for-mation of second high temperature solid phase in the brick by adopting additive,In addition,it is needed to improve the quality of the brick appearance and ensure accurate dimensions of the brick,The purpose of this paper is to further iprove the service life of the refractory bricks by making use of the improvement mea-sures taken on the basis of the analysis results of the used bricks.展开更多
文摘Application of MgO-Cr2O3 brick compsoed of MgO>72%,Cr2O3>14.8%-16.69%,with porosity 13%-4%,compressive strength 33.0-43.8 MPa ,flexing strength 11.9-16.5 MPa and refractoriness under load≥1750℃ in a assembled snorkel of 300t RH funace in Baoshan Iron & Stel Company (Baosteel) showed good results of average service life of 106.6 heats maximum 119 heats.Petrologi-cal analysis and visual examination were also done on the residual brick to investigate thewear mechanism.
文摘This essay analyses three different kinds of insulating boards for used tundish by OM,EDAX and XRD,aiming at disclosing its mi-crostuructue,and tryin to find out its wear mechanism. The SiO2 insulating board has the trans-formation from quartz to α-cristoballite to some extent.It forms a large quantity of glass phases while reacting with slags,which belongs to corrosion wear.The MgO insulating board belongs to both spaling and corrosion wear,for it forms MA,C3MS2, and melilite minerals while reacting with slags,When M2S board reacts with slags,[Fe] of the unchanged 2[Mg,Fe]O·SiO2s.s will be replaced by [Mn] of the slag phases to form 2[Mg,Mn,Fe]O·SiO2.s,leaching Fe ,Which belongs to both spalling and corrosion wear,This essay also makes fur-ther discussion about the three diferent refrac-tory effects on steel quality.
文摘The application results of semi-rebonded magnesite-chrome bricks at RH lowe vessel of NKK Corporation Keihin Works have been analysed,The results indicate that the main reasons that cause the damage of the refactory brcks include:chemical attack of slage to the semi-rebonded magnesite-chrome bricks;pene-tration of molten stel,slag into the bricks;and therma spalling due to temperature fluctua-tion during steel making operation.The results of multiple effection of these factors lead to alternative action of erosion(chemical attack and penetration)and spalling(thermal spalling and structure peeling) resulting in the damage of the brik ,In order to improve the performance of the bricks ,it is necessary to promote the resistance to erosion and thermal shock resistance as well as to keep the accurate dimensions of the brick,The measures of improvement of resistance to erosion of magne-site-chrome bricks taken by the researches mainly include:lowering the contents of impu-rities in the bricks(mainly including SiO2,CaO,and next Fe2O3 and Al2O3);promoting the extent of direct bond of the brick;forming a large amount of magnesia-chrome composite spinel well-distributed in the bricks through adding a large amount of synthesized materi-als;enhancing the resistance to erosion by adding a little amount of high-effective additives,Improvement of thermal shock resistance of the bricks is mainly through introducing some additive to make a certain amount of mi-cro-cracks occur in the brick so as to obtain an effect of increasing toughnes or through for-mation of second high temperature solid phase in the brick by adopting additive,In addition,it is needed to improve the quality of the brick appearance and ensure accurate dimensions of the brick,The purpose of this paper is to further iprove the service life of the refractory bricks by making use of the improvement mea-sures taken on the basis of the analysis results of the used bricks.
