Research Into The Decreasing Oxidation Burning Loss Of Low-carbon Steel Billet

Oxidation is an inevitable problem in the process of hot forming for steel billet,especially in the heating process,due to heating temperature high,time long,and it is also an important reason for steel consumption.Thus,oxidation burning consumption mechanism was studied in high temperature for billet,in order to exploring an effective way to control oxidation burning consumption in industry,which has an significant meaning for companies in energy saving,upgrading of products quality and technology and sustainable development.Meanwhile,that also can enhance economy and social profit for our nation-a steel country.Through decreasing the furnace oxygen partial pressure technology which can reduce the oxidation burning consumption in billet.The study for technology was systematic and profound.Three steel samples were selected,and the grade is 08 Al,SPHD,Q195 respectively.The oxygen partial pressure(Po2)was selected to 4%(simulating working condition Po2),21%(at air,greater than working condition Po2)and less than 0.1%(at nitrogen,less than Po2).The oxidation temperature is simulated to the furnace temperature in rolling company(1150-1250 ?).The oxidation dynamics behavior with decreased of Po2 was studied for billet,and the chemical and phases component,microstructure,and morphological characteristics in oxide layer and relevant region was analyzed in detail.The main conclusion was gained as follow:In the condition of same Po2,the oxidation mechanism(oxidation dynamics,burning consumption and oxide scale structure and so on)are different with different steel,moreover,with the difference of steel's composition larger,the distinction clearer.The oxide layer's forming in high temperature for three kind of steel exist by the subject of Fe O layer which has numerous defect such as void and crackle as the like,and those would transformed into Fe3O4,even though Fe2O3 in the process cooling.The speed of transform is inversed with cooling speed,and the extent of transform is related to steel's composition.Po2 is the main reason in influence on oxidation burning consumption,so the billet's oxidation burning consumption can be decreased by reducing Po2 obviously.All kinds of steel,in three different temperature(1150,1200 and 1250?),the relationship that the oxidation dynamics is decreased obviously with the reducing of Po2 is evidenced.At the temperature of 1250 ?,when Po2 reduce from working condition 4% to less than 0.1%,the burning consumption for three steel can decrease to 70-95%,which is transformed to billet's oxidation burning consumptionless than 0.5% that has been achieved the contract goal absolutely that reduce to the below of 1%.At the temperature of1200 and 1150?,the billet's burning consumption decrease to higher 75% at least through reducing Po2,which is transformed to billet's oxidation burning consumption-less than 0.4% that is also achieve the contract goalIt is effectively that decrease the billet's oxidation burning consumption through decreasing heating temperature.In the condition of 4%O2,the temperature decreasing from 1250? to 1200?,the burning consumption of 08 Al reduce by 12%,while,the SPHD and Q195 reduce by higher 20%.However,when the temperature decrease to 1150?,the burning consumption of 08 Al reduce by 24% compare with 1250 ?,and SPHD is 30%,Q195 is higher 40%respectively.Comparably,it is more effectively that decrease billet's oxidation burning consumption through reducing Po2 rather than decreasing temperature.