Cu、Nb及預(yù)變形對ULCB鋼中ε-Cu析出的影響.pdf

1、分類號UDC密級烈5薹甜張走哮碩士學(xué)位論文cu、Nb及預(yù)變形對ULCB鋼中e—Cu析出的影響張胤彥指導(dǎo)教師姓名：袁澤喜教授武漢科技大學(xué)材料與冶金學(xué)院申請學(xué)位級別論文定稿日期學(xué)位授予單位學(xué)位授予日期碩士專業(yè)名稱：論文答辯日期20051205武漢科技大學(xué)答辯委員會主席：劉靜教授評閱人李平和教授級高工謝光遠(yuǎn)副教授魚!L生武漢科技大學(xué)碩士學(xué)位論文AbstractTheaginghardeningresponseofaseriesofultral

2、owbainiticsteelscontainin￡copperhavebeeninvestigatedTheeffectofvariouscoppercontentadditionsomealloyelementsandpre—deformation(addingpredeformationprocessbetweensolutionandagingtreatment)onagingkineticsbehaviorofprecipit

3、ationhardening，theprecipitatesdistributionandmicrostruetureevolutiondudngagingWaSdiscussedbymeansofhardnessmeasurement，lightmicroscopeandTEMTheresultsindicate：IThreekindsofprecipitates￡Cu，Nb，Ti(C，N)，F(xiàn)e，Mocarbideduringagi

4、ngresponsehavebeenobserved，theyleadtotheaginghardeningThesecondhardnesspeakappearingafteralongperiodsagingwasattributedtotheprecipitationofFe，MocarbideAttheearlystageofagingtherearetwohardnesspeakscausedby8一CuNb，r1(c’N)r

5、espectivelyinsteel晰th152％copperbutthereisonlyonehardnesspeakinsteelswitll098％copper2TheagingkineticsofCuaddedsteelsisstronglydependentontheagingtemperatureandthecoppercontentIncreasingtheagingtemperatureincreasestheaging

6、kineticsanddecreasesthemaximumhardnessWhenthecoppercontentofsteelsincreasesthehardeningeffectincreasesandthenucleationandgrowingofeCuprecipitatewasaccelerated3、ⅣiththeincreaseofcoppercontentofsteeltheNbearbonitrideprecip

7、itationinbainiteacceleratedWhenthecontentofcopperis152％theNbcarbonitrideprecipitationwaspromotedobviouslybutwhenthecontentofcopperis098％thereislittleinfluenceontheNbcarbonitrideprecipitation4￡一Cunucleatedattheboundaryofb

8、alnitelathretardstherecoveryofbainitestructureduringagingandsuppressesthesofteningofthematrix5Thesteelswhichhavepre—deformationprocess，thetimeofappearinghardnesspeakcartbeshorten，andtheheightofhardnesspeakisalsoheightenW