12 铸坯形状缺陷控制.pptx

连铸坯形状缺陷的控制

Controlofshapedefectofcontinuouscastingslab;形状缺陷产生的原因分析

1）凝固过程

2）连铸设备

3）工艺参数控制

Analysisofthecausesofshapedefects

1）Solidificationprocess

2）Continuouscastingequipment

3）Processparametercontrol;;鼓肚变形dilatancydistortionorbulgingdeformation

带液心的铸坯在运行过程中，于两支撑辊之间，高温坯壳中钢液静压力作用下，发生鼓胀成凸面的现象，称之为鼓肚变形。板坯宽面中心凸起的厚度与边缘厚度之差叫鼓肚量，用以衡量铸坯彭肚变形程度。

Duringtheoperationofslabwithliquidcore,underthestaticpressureofliquidsteelinthehightemperatureshellbetweentwosupportingrollers,bulgingtoconvexsurfaceoccurs,whichiscalledbulgingdeformation.Thedifferencebetweenthecenterbulgethicknessandtheedgethicknessofslabwidesurfaceiscalledbulge,whichisusedtomeasurethedeformationdegreeofslabbulge.;鼓肚变形bulgingdeformation;Schematicdiagramofbilletbulge;铸机本身刚度不够，二冷夹辊间距过大，或刚度不够，或辊径中心调整不准

Therigidityofthecasteritselfisnotenough,thedistancebetweenthesecondarycoolingpinchrollsistoolarge,ortherigidityisnotenough,ortheadjustmentoftherolldiametercenterisnotcorrect;减少鼓肚的措施

Measurestoreducebulgingdeformation;◆菱形变形RhombicDeformation

菱形变形也叫脱方。是大、小方坯的缺陷。是指铸坯的一对角小于90°，另一对角大于90°；两对角线长度之差称为脱方量。

Rhombusdeformationisalsocalledsquarebreaking.Itisthedefectoflargeandsmallbillets.Itreferstothatonediagonaloftheslabislessthan90°andtheotherismorethan90°.Thedifferencebetweenthetwodiagonallengthsiscalledtheoffsquarequantity.

坯壳在结晶器内不均匀冷却所引起的

Causedbyunevencoolingofshellinmold

;应对菱变的措施

MeasurestodealwithRhombicDeformation;圆铸坯变形Roundbilletdeformation

圆坯变形成椭圆形或不规则多边形。圆坯直径越大，变成随圆的倾向越严重。形成椭圆变形的原因有：

1）圆形结晶器内腔变形；

2）二冷区冷却不均匀；

3）连铸机下部对弧不准；

4）拉矫辊的夹紧力调整不当，过分压???。

Thebilletchangesintoanovalorirregularpolygon.Thelargerthediameterofthebillet,themoreseriousthetendencyofturningintoacircle.

Thecausesofellipticaldeformationareasfollows:

1)Theinnercavityoftheround