易切削钢中夹杂物及锡的形态.pdf

265Vol.26No.5200410JournalofUniversityofScienceandTechnologyBeijingOct.20042004–01–1458No.50274004[1~8],[9]11.120kg18kgQ235%C0.17Si0.31Mn0.07P0.020S0.025100g35gCaO,35gSiO2,30gAl2O3Mn69.4%,C1.37%(70~80)×106FeSC60mm×200mm115040mm1.26mm×35mmM1280mmMTS810HB–3000B10mm12s1.310mm×10mm400,800,1000,1200,15001.422.1Y20Sn(GB/T87311988)1CSSnMnSiPY20SnCSPY20SiY20MnY202.2212Sn0.05Y20Y20Y20SnSiMnSi1)1)1)1)1)2)1)1000832)2711040.05%()MnS,TF741.322•472•20045MnSiMnHB160~200[9]2.31Y20SnMnOSiO2MnS[7]SnSn(c)MnS[10]2.4211Y20Sn(GB/T87311988)()Table1CompositionsofY20Snandthesteelsofthenationalstandard(GB/T87311988)%CSiMnSPPbSn1Y20Sn0.210.560.800.280.0680.0132Y20Sn0.200.600.800.280.070.0493Y20Sn0.200.580.790.290.0680.088GB/T87311988Y15Pb0.10~0.180.150.80~1.200.23~0.330.05~0.100.15~0.35GB/T87311988Y200.17~0.250.15~0.350.70~1.000.08~0.150.062Y20SnGB/T873111988Table2MechanicalpropertiesofY20Snandsomesteelsofthenationalstandard(GB/T87311988)/MPa/%/%HB1Y20Sn46329.3355.411222Y20Sn45728.8858.751223Y20Sn41110.0027.16122GB/T87311988Y15Pb390~45022.0036.00170GB/T87311988Y20450~60020.0030.00175(a)(b)(c)Pb1Y20SnFig.1EBSDimagesoftheinclusionsofY20Snsample2Y20Sn.(a)(b)Fig.2FractureofthemechanicaltestingsampleofY20Sn(a)(b)ABVol.26No.5•473•30.013130.963MnSMnO,SiO21PenningtonJN.Greensteeleliminateslead[J].ModMet,1999,55(11):382SomekawaM,KaisoM,MatsushimaY,etal.Freecuttingsteelswithoutleadaddition[J].KobeResDev,2001,51(1):133RadulescuAG,AshtonJD,BroughtonLR,etal.Machi-nabilitycomparisonoftin-bearingreplacementforfree-machiningsteels[J].IronSteelSoc/AIME,2001,39:454YamamotoS.Developmentoffreecuttingsteelwithoutlead[J].NetsuShori2000,40(3):1045ReynoldsPE,AbernethyK,GilroySP.Theeffectofcop-perandtinonthepropertiesofstructural,wirerodandfreecuttingsteels[J].RecyclMet1999,June:2316BernsmannG,BleymehlH,EhlRiHassler.Themakingoffreecuttingsteelswithadditionsoflead,bismuth,tellu-rium,seleniumandtin[J].StahlEisen2001121(2):877MasonF.Free-Machiningsteel,unleadedstyle[J].AmMach[J].1991,135(12):518.[J]..2003,25(4):3129.[M].,199910,.2618[J].,2001(6):21FormandDistributionofInclusionsandTininFree-cuttingSteelLILiansheng1),ZHURong1),SUNYanhui1),GUOHanjie1),YINHao1),DONGJie2)1)MetallurgicalandEcologicalEngineeringSchool,UniversityofScienceandTechnologyBeijing,Beijing100083,China2)TechnologicalCentre,LaiwuSteelCo.Ltd,Laiwu271104,ChinaABSTRACTAfreecuttingsteelcontainingtinlessthan0.05%inmassfractionwasdeveloped,whichpossessesgoodmachinabilityandsatisfactorymechanicalpropertiesmeetingthenationalstandardofChina.TheformsanddistributionofinclusionsandtininthesteelwereinvestigatedbyobservationsofthesteelsamplesandthefractureofthemechanicaltestingsamplesbymeansofSEMandEDS.Theresultsshowedthatthecomplexinclusions,nod-ularorspindle-shaped,werecomposedmainlyofoxidesandmangnesesulphide.Itwasfoundthattherewerema-rkedsegregationoftininthefractureandonthesurfacesofinclusionsinthesteel.KEYWORDSfreecuttingsteel;tin;inclusions3Y20SnTable3Compositionofinclusionsinthefractureofthesample%FeSiMnPSCaSnAl3132193.650.543.800.001.530.180.300.0031321(A)33.270.6138.110.1426.870.200.800.0031321(B)22.770.4142.120.3632.740.040.960.60