简介:Non-metallicinclusionisthemainreasonforthepresenceofsurfacedefectsincold-rolledsteelstrip.Inthisstudy,thecomposition,morphology,andsizeofthenon-metallicinclusioninhot-rolled304stainlesssteelstripsareanalyzed.Cold-rolled304stainlesssteelstripswithdifferentcold-rollingreductionhavebeenprepared,andthemorphologyandsizeofinclusioninthesecold-rolledstripsarealsoanalyzed.Furthermore,thedeformationbehaviorofanon-metallicinclusionduringthecold-rollingprocessisstudied.TheresultsshowthatCaO-SiO2-MgO-Al2O3,akindofbrittlecompoundoxide,isthemaintypeofinclusioninhot-rolled304stainlesssteelstrips.Duringthecold-rollingprocess,ductiledeformationofthistypeofinclusionisnotobvious,wherelargeinclusionsarecrushed,andtheaveragesizeofinclusionsincold-rolledstripsdecreasedwhilethecold-rollingreductionincreased.
简介:GlowdischargeplasmanitridingofAISI304austeniticstainlesssteelhasbeencar-riedoutfordifferentprocessingtimeunderoptimumdischargeconditionsestablishedbyspectro-scopicanalysis.ThetreatedsampleswereanalysedbyX-raydiffraction(XRD)toexplorethechangesinducedinthecrystallographicstructure.TheXRDpatternconfirmedtheformationofanexpandedaustenitephase(γN)owingtoincorporationofnitrogenasaninterstitialsolidsolu-tionintheironlattice.AVickersmicrohardnesstesterwasusedtoevaluatethesurfacehardnessasafunctionofindentationdepth(μm).Theresultsshowedclearevidenceofsurfacechangeswithsubstantialincreaseinsurfacehardness.
简介:Objective:Toobservetheeffectsofthermalstressonproliferationofhumanvascularendothelialcells(VECs)andexploreitssignificance.Methods:ChangesofVECsproliferationwereinvestigatedwith3H-TdRincorporationmethodafterECV304wastreatedat43℃for2hours,whileexpressionsofintercellularadhesionmolecule-1(ICAM-1),inhibitorofdifferentiation-1(ID1),andP16andP21proteinsweredeterminedbyWesternBlotting.Results:TheeffectofinhibitionofVECsgrowthafterthermalstresswasdetectedby3H-TdRincorporationexperiment.WesternblottingshowedICAM-1,amarkerofactivatedendothelialcells,wasincreasedmarkedlyafterthermalstress.ExpressionofID1proteindeclinedgraduallywithincreasingexpressionsofitsdownstreamgenes,P16andP21followingthethermalstress.Conclusions:ThermalstresscouldstronglyactivateVECsandinhibitproliferationofVECsthroughID1,thusdownregulatingcyclin-dependentkinaseinhibitors,P16andP21,whichmightbeanessentialpathwayforrecoveryofVECsafterthermalstress.
简介:The304stainlesssteelstripsweredepositedonelayeroncarbonsteelbasemetalbyelectroslagstripcladding(ESC)andsubmergedarccladding(SAC),respectively.ThesolidificationmicrostructureofESCmetalwasanalyzedbytheopticalmicroscopy,scanningelectronmicroscopeandenergydispersivespectroscopy.Thecorrosionresistancestudiesofstripcladdingmetalswerecarriedoutin10%oxalicacidelectrolyticetchingtest.TheresultsshowedthatthecladdingmetalobtainedbyESCpresentedlowcontentofC,highcontentofCrandenoughalloyingelementofNiinthechemicalcomposition.ThetransitionzoneofESCwithsmallwidthwasalmostparallelwiththebasemetal,leadingtoalowerdilution.Therearethreetypesofsolidificationmodes(A→AF→FA)occurredintheESCmetalduetothedecreaseofcoolingrateanddegreeofdilutionfromthetransitionzonetothetopofESCmetal.Asaresult,themicrostructureofESCmetalexhibitedmainlyaustenitewithasmallamountofferrite,contributingtoachievementofbettercorrosionresistance.
简介:SUS304stainlesssteelistypicalofausteniticstainlesssteel,whichorganizationismetastableaustenite,easilyappearsworkhardeningincoldrolling.Accordingtothecommonprocess,themaxreductionofcoldrollinginonestageisbelow80%,wetrytorasiethemaxreductionto90%inonestage(wecalledthat'greatreduction')fromtheviewofcutingcost.Duetotheworkhardening,greatreductionbringslotsofproblem(thedifficultyofflatnesscontrol,stripbreak..etc)。ThisarticleanalyzedthegreatreductionfromproperityofSUS304steel,milltypes,flatnesscontrol,rollingtechnicsetc,suppliedthecorrespondingsolutions,andformedasophisticatedgreatreductiontheory.Thisarticlefocusesontheunusualthermalcrownofrawmaterials(ie,abnormaldistributionofhorizontalthickness)andtherollingforcefluctuationsin'greatreduction'rolling.First,the'distortion'phenomenonwhichcausedbyunusualthermalcrownofrawmaterialsisexplained,wedge-shapedstripIncoiling,becauseofabigdifferenceinthicknessonbothsides,leadstodifferentcompressivestressonbothsidesofflatnessroll,sothattheflatnessmeasurementisdistorted;Second,the'stripshifting'phenomenoncausedbywedgeshapeofstripisexplained,weanalysisthestressonbothsidesofthestrip,concludedthatthewedge-shapedstriponthecoilerwillshifttothethicksideofthedeviation,theamountofstripshiftingisrelatedtothewedgelevel;BecauseofthecharacteristicsofSUS304,thestripisdifficulttoberolledinthelastfewpasses.sothestripbreakingiseasilyoccurred,wefoundthereasonableparameters(rollingspeed,coolingoil,tension,etc)tosolutethatproblem;Thedeviationofrollingforcewillcausetheshapeoftherollgap,thusaffectingtheshapecontrol,especiallyintheheadandtailpartofthestrip,Itisimportanttominimizethedeviationofrollingforce;The'greatreduction'processprovidethefavorableflatness(<8I-unit)andthicknessdeviationwhichlessthan±3um,withnosi
简介:摘要目的探讨子宫内膜息肉(EPs)发病的相关高危因素。方法回顾性分析滨州医学院附属医院2019年10月至2020年9月因异常阴道出血、超声提示宫腔内异常行宫腔镜检查的患者669例的临床资料,根据术后病理结果分为两组,其中EPs组患者(息肉组)304例,非EPs组患者(非息肉组)365例。记录患者的临床资料,用SPSS 22.0统计软件进行单因素及多因素分析。结果单因素分析显示,年龄(息肉组中位数为45岁,非息肉组为47岁)、孕次(息肉组中位数为2次,非息肉组为3次)、产次(息肉组中位数为1次,非息肉组为2次)、绝经(息肉组49例,占16.12%;非息肉组83例,占22.74%)、慢性子宫内膜炎(息肉组111例,占36.51%;非息肉组174例,占47.67%)、宫颈息肉(息肉组58例,占19.08%;非息肉组46例,占12.60%)、高血压(息肉组48例,占15.79%;非息肉组88例,占24.11%)、糖尿病(息肉组14例,占4.61%;非息肉组31例,占8.49%)等是EPs发生的危险因素(Z=-3.71、-4.30、-2.50,χ2=4.59、8.44、0.02、0.01、0.04,均P < 0.05)。多因素分析提示,年龄、孕次、慢性子宫内膜炎、宫颈息肉对EPs发病有明显影响(OR=0.97、95%CI 0.95~0.99,OR=0.80、95%CI 0.72~0.90,OR=0.53、95%CI 0.38~0.74,OR=1.73、95%CI 1.10~2.72,均P < 0.05)。结论年龄、孕次、慢性子宫内膜炎、宫颈息肉均为EPs发病的相关高危因素。