Development of the steel AISI 4145HM for senior petroleum drill of BX Steel

The Steel AISI 4145HM for senior petroleum drill of BX Steel was produced by the follow sheet: hot metal pretreatment→converter→LF→RH→caster 350 mm×470 mm rectangular billet→hot delivery→reheating→800 mill rolling→insulation→straightening→anneal→grinding→inspection→packaging and pay into treasury→shipment.Selected BX Steel particular hor metal,adopted hot metal desulphurization pretreatment technology.The LF refining making the white slag,and keep a certain time.The RH treatment must make sure the vacuum degree and refining time,more importantly controlling argon blowing process.In addition,must design proper technology data continuous casting similar superheat,casting speed,and specific water flow rate.Depend on technological measures,the product been had series of the qualities:homogeneity of chemical composition,low content of harmful elements,high purity,compact organization.Adopted the process of casting billet hot delivery and hot charging,used stepping heating furnace,and designing reasonable thermal parameters.Two -high reversing mill rough rolls preparation square billet,short - stress - path rolling mill rolls round bar.Steel products bad holding and controlling soaking time and temperature. Steel products bad annealed,and annealing process must been controlled for ensuring steel hardness uniform. For avoiding residual stress,steel been straightened before anneal.The test results and using effect shows that the producing with uniform annealing hardness and nice processing properties,nice overall mechanical properties,were recognized by users.