P91钢轧制钢管翅皮、孔洞缺陷分析

Analysis of scab and cavern defects for rolled seamless P91 steel tubes

通过对P91钢毛管内表面翅皮及钢管的检测分析,探讨了P91无缝钢管在轧制过程中毛管内表面出现翅皮缺陷和钢管出现孔洞缺陷的原因。结果表明,翅皮表面有复合型夹杂物,成品管中有B类复合型夹杂物,这种复合型夹杂物是形成翅皮缺陷、钢管出现孔洞缺陷的主要原因。复合型夹杂物是Al2O3和Na2O-CaO-MgO反应产物,Al2O3非金属夹杂物主要是炼钢时Al和O的反应产物(铝脱氧),Na2O-CaO-MgO是炼钢时作为N加入剂用的氮化铬铁FeNCr10-B带入的Na2O、CaO、MgO复合型夹杂物的反应产物。

The cause of the scab defects in the internal surface of semi-manufactured tubes and cavern defects in the tubes during rolling seamless P91 steel tubes were discussed by measure and analysis of scab and tube of P91 steel tubes.The results show that there are compound inclusions on the surface of scab defects and B-kind compound inclusions in the tubes.The compound inclusions are the main causes for producing scab and cavern defects.The compound inclusions is the reaction product of Al2O3 and Na2O-CaO-MgO,and Al2O3 inclusions are the reaction products of Al and O in the process of steel making（deoxidation with aluminium）.Na2O-CaO-MgO compound inclusions are the reaction products of Na2O,CaO and MgO that were added in steel making furnace along with the FeNCr10-B webbite for N.