NGHIEN COfU - TRAO D O I N C H I E N C(i\J SI/ A N H H l / d N C CUA T H I E U KET T d i T I N H CHAT CUA L P PHU K I M LOAI TS Hodng Viin Gptt, ThS Vu Van Khoa Vi?n Nghien cau Cd TOM TAT Xd ly nhiet tdi xdp xi nhiet ndng chdy Idp phu (cdn ggi Id thiiu k^t) sau phun phu Id mdt bU cua qud trinh phun phu kim loai Thieu kit cd vai trd quan trgng tdi tinh chdt cua Idp phu: tdng dd dinh giUa cdc phdn td Idp phu, tdngdgbdm dinh cua Idp phu vdi kim loai nin, Idm thay doi cdng I phu Su dnh hUdng cua thiiu kit dd ndng cao chdt lUdng Idp phu ANH HlTONG CUA THl£U KET TOI D O BEN KEO VA DO C C N G Viec nghien cau sU dnh hudng cua thieu ket tdi chat lugng Idp phu, dugc tien hdnh bang thUc nghiem tai Trung tam Hdn vd Xd ly be mat Vien Nghien cau CP Qud trinh dd dUpc tien hanh nhU sau: Qua trinh nung chay Idp phu: Chi tiet dupc ga tren thiet bi chuyen dung, dam bdo dong tam vdi true mdy, quay vdi toe dp cham, chi tiet dupc nung bang mpt dau d6t dxy-axetylen (hinh 1) Dau ddt hudng trUc tiep vao b^ mat chi tiet va tien hdnh nung den xuat hien mdu hong (nhiet dp xap xl 760-870''C) Sau dd, dau ddt di chuyen dgc true vdi van toe cho that deu, tam cua ngpn laa hUdng vdo tam cua chi tiet ta tren xuong tren be mat cua Idp phu Dau ddt cU tiep tuc di chuyen dpc true chi tiet cho den xuat hien mau sdng, xap xi nhiet dp ndng chay Idp phu (nhiet dp thieu kgt khodng 1025 - 1175''C), dd, phai dieu chinh tam cua ngpn Ida xa be mat ciia chi ti^ de gidm cUdng dp cung cap nhiet, de phdng Idp phu bi chay Can tri tinh trang ndng chay d thdi gian rat ngan nhat dinh (thdi TAP CHi CO KHi V I £ T NAM • gian thieu ket) de dam bao thieu ket dupc Idp phu dUpc ddng deu \:,Mi^ •-,>it-.:-ffU"'••***^-> Hinh 1: Thieu ket Idp phu bdng mpt dSu d6t oxyaxetylen tren thiet bi chuyen dung LAM N G U O I Chi tiet sau xii ly nhiet phai dUpc dam tP khdng xay nat Idp phu co ngdt cua kim loai Idp phu Do vay, tien hanh lam ngudi cdc chi tiet dieu kien khdng tinh Sau chSp diS cung cap nhiet cho Idp phii la bat dau qua trinh 1dm ngudi vd chi tiet van quay cham (8 v6ng/ phiit) de chdng bien dang cd th^ xay chi tiet dang d nhiet dg cao gan lOOO^C S6 (Thang nam 2012) NGHIEN COfU-TRAODOl CHE DO T H O I GIAN THifiU KET De cd ca sd so sdnh vd ddnh gia, cac mau dupc xd ly nhu sau: - Sd lupng mau thd: hai loat mau vdi nhdm mau vdi chieu day Idp phu 2mm va 0,5mm; - Thdi gian tri nhiet dp thieu ket cho nhdm mau tuang ang: 5s, 10s, 15s va 20s ANH HCdNG CUA THIEU KET T O I D O BEN BAM TRUOT, D O CUISTG V A CHIEU phun bdng cung mdt che dp phun Ket qua cho thay, dp ben keo trung binh sau thieu ket tang ban Ian so vdi trUdc thieu ket 4.2 Anh hudng cua thdi gian thiiu kit dSn ben kio Thdi gian tri nhiet dp thieu k^t gay dnh hudng den dp ben Idp phu De cd ca sd ddnh gid sU dnh budng dd mau dUpc thieu ket vdi thdi gian khdc nhU neu tren: Ket qud thi nghiem bdng cho thay, dp ben keo cung tang theo thdi gian thieu ket tdng (dd thi hinh 2) D A Y L P KHUECH T A N Dp bam dinh cua idp phu vdi be mat kim loai n^n thUdng dUpc kiem tra Ung suat theo ca hai phuang phap: tiep tuyen vd phUPng phap tuyen NhUng de kiem tra sa dnh hUdng cda xii ly nhiet, cd the chi xem xet mau tha: mau tha ben keo, bdm trUpt vd mau tha dp ben bam dinh Ndi dung thi nghiem dupc thUc hien nhu sau: Lay mau tha cd kich thudc O 25 x 14, Idp phun phu day 2mm, vat lieu kim loai nen: thep C45, vat lieu phu: nhdm hpp kim nhdm: Ni-Cr-Si-B Cdc mau dUpc phun theo bd thdng sd tdi Uu da chpn, xii ly nhiet theo phUPng phdp ngpn laa dxy-axetylen Chieu ddy Idp khuech tan dupc tren mdy quang hpc cua Lien Xd H M T - 3, kiem tra dp ben keo va bdm trUpt tren may YMM - 30 vd dp cdng Rocoel dUpc tr6n mdy TK - 14 cua (Lien Xd cu) Phan tich k^t qua thi nghiem 4.3 Anh hudng cua thdi gian thiiu i t den Ciing vd chieu day Idp khuech tdn De nghien cau sU anh hUdng cua thdi gian thieu ket den dp cdng cua Idp phu, da thieu ket hai loai mau: mpt loai cd chieu ddy Idp phd 2mm va mpt loai cd chieu ddy Idp phu 0,5mm Vdi thdi gian thieu ket khac nhau: 5s, 10s, 15s, 20s vd cdc mau dupc phun bang mpt che dp, cang mdt dieu kien ky thuat Ket qud thUc nghiem bdng vd cho thay: -Loai mau cd chieu ddy Idp pha 2mm thi dp cdng gan nhu nhau; - Cdc mau cd chieu ddy 0,5 mm thi dp cdng gidm dan thdi gian thieu ket keo dai ban, dd thi hinh - Chieu ddy Idp khuech tan cua cac mau tang Ien thdi gian thieu ket tang Ien, thi hinh 3; - Dp ben bdm dinh cac phan td Idp phu cung tang Ien thdi gian thieu ket tang, dd thi hinh De nghien cdu dnh hUdng cua viec thieu ket den dp ben bam cua Idp phu, can phdi xem xet van de chinh sau: 4.1 So sdnh ben keo trUdc vd sau thiiu kit De so sanh ben Idp phu trUdc va sau thieu k ^ da dUpc ki^m tra dd ben keo (4 mau) trUdc thieu ket vd kiem tra dp ben keo (4 mau) sau thi^u ket (bang 1) Tat ca cac mau dUpc Hinh 2: Do thi phu thupc giCa thdi gian tri nhiet dp thi^u ket va dp ben keo "^ TAP CHi CO KHi VIET NAM V Sd (Thang nam 2012) NGHIEN CUU - TRAO OPl £(nm) 60 40 20 '^ ^, 10 15 20 l(s) Hinh 3: Do thi sU phu thupc giQa thdi gian thieu keft vd chi^u ddy Idp khuech tan Bang 1: Ket qua kiem tra mau tha sau thieu ket Ghi chu Cac thong sd ki€m tra Ihdi gian tri d nhiet ndng chay (S) So mau Do ben k^o cua Idp phu (MPa) Dp cuing be mat Idp phu (HRC) Chieu day Idp phu Chieu day Idp phii 2mm 2mm 0,5 m m 392 53 48 10 391 52 47 15 414 51 41 20 432 52 37 404,75 52,125 43,25 Gia tri trung binh i Bdng 2: Ket qua kiem tra chieu ddy Idp khuech tan S6mau Thdi gian tri Dp cllfng (HRC) (s) Chieu diy Idp khuech tin (^m) Dp ben bam tnipt (MPa) 9,450 25,3 52,6 10 11,865 41,0 46,7 15 23,730 52,6 41,3 20 35,62 62,7 23,7 I33I TAP CHi CO KHi VIET NAM • S6 (Thang nam 2012) NGHIEN ClJU - TRAO OOl theo thdi gian; t - Thdi gian tri nhiet dp ndng chay; D - He sd khuech tdn cmVs; B - He sd khdng thd nguyen HRC 60 40 ^^ j 20 He sd tan ddng (D) se thay ddi tang Ien thdi gian thieu ket tang vd dieu ndy keo theo chieu ddy Idp khuech tdn (e) tang theo, SU tang (e) thdi gian thieu ket (t) nhat dinh man theo quy luat 10 15 20 Kiem tra dp ben keo dUpc kiem tra tren mau dieo tieu chuan caa Nhdt bdn JISH 8664 - 1977 Anh mau tha ben keo trUdc vd sau keo ddt the hien tren hinh 5a va 5b t(s) Hinh 4: Do thi phu thupc giUa thdi gian tri nhiet dp thieu ket va dp cang Idp phu (dp day Idp phu 0,5 mm) Td phan tich ket qud thi nghiem (Bang 1,2) tren cho thay: Dp ben keo cua Idp phd : - TrUdc thieu ket trung binh: 76,8 MPa; - Sau thieu ket trung binh: 404,75 MPa Hinh 5: Mdu tha 44 x 65 mm a TrUdc keo dat b Sau keo dat Dp Cling be mat Idp phu; - TrUdc thieu ket trung binh: 39,4 HRC; - Sau thieu ket trung bmh: 52,125 HRC; - Dp cdng Idp phu gidm sau thieu ket ddi vdi Idp phd cd chieu ddy 0,5nmi 4.4 Anh hudng cua thieu ket tdi cau true kim tUdng cua Idp phd - Cau true kim tUcfng cua cdc mdu trUdc xii ly nhiet cd dp xdp cao (hinh 6a) cdn cua mau sau hi \u h nhittt-ui tiu khoni,nhm lhi\ o lo xoj Chieu day vung khuech tan tang; - Chi6u day Idp khuech tan tang thdi gian thieu ket tang: NgUdi ta da chang minh dUpc rang, chieu day Idp phu tao bang cdc nguyen td khuech tan d vung chuyen tiep la ham sd phu thudc vdo thdi gian tri nhiet ndng chdy (cdng thdc 1) £ = 2ByjDt (I) Trong do; : - Chieu day cua Idp khuech tan thay doi a b Hinh 6: Cau triic kim tuang cia Iclp phi tii hop kim nhom Ni Cr Si B a-TrU6c xii ly nhiet, b- Sau xii ly nhiet Nhtoxet: TAP CHi C O KHi VIET NAM •> Sfl (Thang nam 2012) NGHIEN CUU - TRAO D P I Ta phan tich sU khac bi?t ve ket qud kiem tra mau tha, ta nhan thay rdng; cau trdc kim tUPng dugc cdi thien nhd vi$c nung chdy da 1dm thodt dxyt ngodi Idp phii, cdc phan ta kim loai phu dUPc ndng chdy da dien day cdc Id xdp Idp pha NhUng nguyen nhan ay da Idm cau true Idp phu dapc l^n chdt Dd b ^ i k^o cua Idp phu tang nhieu cdc nguydn nhdn sau; - Kim tuang Idp phu dupc cdi thi?n Idm tdng sp lien ket cua cdc phan ta kim lo^i; vd M2,(bdng 3) vd sau xii ly nhi^t (bang 4) Bdng 3: Thdnh phdn hda hpc ban din cua Ni77Crl5Si; TT K> hi^u mau M M: Ham lirovg (%) Cr Si B Ni 77 1;J 1;2 77 Ghi cbii 1 3.1 3.1 1 Bdng 4: Thdnh p h l n hda h p c sau xii If nhi^t cua - Cdc nguyen td kim loai nen da khuefch tan dan xen vdo Idp phd, tao nen sU lien k^t ben vflng han; Ni77Crl5Si3B2 : i Ki - chieu day du Idn va thdi gian thieu ket thich hpp, cUng cua Idp phu tang Ien Id Idp phu dugc Ien chat sau xd ly nhiet; - Mat khdc, d chieu ddy nhd 0,5 mm, cdng cua Idp phu bi gidm di thdi gian tri nhiet ndng chay keo dai, nguyen nhdn Id tang thdi gian cua qua trinh khuech tan cda cac nguyen td kim loai nen cd cP tinh thap vdo Idp phd Ty le pha trdn cac nguyen to kim loai vdo Idp phu cdng cao thi ca ly cda Idp pha cdng bi giam Do vay, thdi gian tri nhiet ndng chay thieu ket phai hpp ly de can doi cdc chi tieu ve dp ben bam vd ca tinh be mat Idp phu 4.5 Anh hudng ciia thieu ket den thdnh phdn hod hgc cua Idp phu Di kiem tra thdnh phan hod hpc caa Idp pha sau xii ly nhiet, da dUpc phdn tich hai mau M l va M2 ta hpp kim Ni77CrlSi3B2 Cac mau dupc phun theo che dd: khodng each phunl70 mm, dp suat thdi: 0,3 MPa, dp suat dxy: 0,2 MPa, kim loai nen: thep C45 cd kich thUdc , Idp phu ddy mm Sau phun, Idp pha dUpc xa ly nhiet vdi thdi gian thieu ket cho mau M1: 5s va cho mau M2: 7s Vat lieu cua cac mau dugc lay tai mat tiep xuc giOa be mat Idp phu vdi kim loai nen Vat lieu dupc phdn tich thdnh phan hda hpc theo phupng phap khdng pha mau co dien Thanh phan hod hpc ban dau cua mau M l TAP CHi CO KHI V I | T NAM • Him I m g (%) hicu Hioi giin mau i!l M M: : NI Si I't-li •ft'- • '.'^ GUch B Fe : ;:; n ^ Nhan xet: Ta ket qua phdn tich phan hda ho caa mau sau xii ly nhiet cho thay: • Hdm lupng cua mpt sd nguyen td gidm di nhil Ni, B hi giam di, nguyen nhan mat mat tronj qua trinh phun phu; Hdm lupng cua nguyen td sdt (Fe) tang leu nhieu; Hi?n tUgng nguyen to Fe tang them nhieu phan Idp phu tai vung tiep giap viii be mat kim loai nen thep C45 cho thay nguyen tS Fe da khuech tan sang Idp phu thdi gian thieu ket keo ddi; • Ham lupng nguyen td Fe khuech tan ta kim loai nen thep C45 sang Idp phu la nguyen nhan lam giam cang cua Idp phu cd chieu ddy nh6 Ta phan tich tren cho phep kit luan; Tiiy thugc vao chieu day Idp phu thdi, gian thieu ^ lUa chpn phdi phu hpp di dam bao dp cang choli^ phu Ket luan cd y nghia thUc tien r5t cao troDg cdng tac phyc hdi vd xit \f be mat chi tilt may *•' Sd (Thang nam 2012) NGHIEN CUfU-TRAODOl Tdi li^u tham khao: [1] H o a n g Tung (1994), P h u n p h u va ilng dyng, NXB, Khoa hpc vd Ky thugt, Hd Npi [2] H o a n g Van G p t (2002), Nghien c a u dnh hUdng cua mpt so yiu to cong ngh^ den dp b i n bam dinh Idp p h u n kim loai dUpc p h u n bdng p h u o n g phdp nhi?t khi, lu^n van Tien sy ky thuat [3] H.A AMenbMeHKO M Apyriie (1990), OnpefleneuHe pacxoflHbix xapaKTcpwcTHK npii HaneceHWH raaoiepMMHecKHX nopwTHH, CBapo4Hoe npoMSBOACTBO, (NGU) MocKsa "MaiuMHOCTpoeHMe" [4] A r BpHFopbAHU (1989), OcHOBbi nasepHoii o6pa6oTKH MeTannoe, MocKsa "MauiHHOCTpoeHHe" [5] A E BawnepMaH w flpyrwe (1969) nnaaMCHHaji uan/iaeKa Meian/iOB, "MauiHHOCTpoeHMs", JleHHHrpajt [6] 71 K flpyjKHH, B.B.KypHHHOB (1973), FIonyMeHHe noKpbiTHH BWCOKO - TCMnepaTypHbiM pacnbineHneM, MocKsa AiOMHSjiaT [7] BysbioH (1993), MccjieflOBaHne H paapadoTKa npoMecca B03flymH0 nnasMeHHoro HanbineHMH H3HOCOCTOHKHX noKpbiTWH H3 nopouiKOB Ha ocHOBe acencsa, KaHflMflaTCKaa flHCcepTauHfl TexHHiecKHx HayK, CaHKT - nexepdyprcKMH rocynapCTBeuHbiii TexHMHecKnii yHMBepcwTCT, CBHT - neTepdypr [8] M K) 3aiii;iJinHH, B B MHTpo4)aHOB H Apyrwe (1986), ITnasMeHHwe KepMexHbie noKpbiTHH na OCHOBC KapdoHHxpHAa iHTana, CBapoMHoe npowsBOflCTBO, (NOI) MocKBa "MauiMHocTpoeHwe" [9] B C KyHHKMH, r K TleTpoB, B A K)mMH (1985), CxpyKTypa H xapaKTepMCTHKM nnasivieHHbix KopyHflOBbix [ noKpwTHH, CBapOMHoe npoH3BOflCTBO, (N08) MocKsa "MaiUHHOCTpoeHHc" ' [10] M /I KynpHflHOB, A A BepciaK H flpyrne (1986), BTiHJiHMe naKnena nosepxHOCTH OCHOBH na (|)H3WKOxMMMiecKoe BsaHMOfleHCTBwe MaxepMa/iOB npw rasoTepMHnecKOM HanbineuMH, CBapoHHoe npoMSBOflciBO, (N01)MocKBa"MamMHOCTpoeHHe" TAP CHi CO KHi VIET NAM V Sd (Thang nam 2012) ... sau: Lay mau tha cd kich thudc O 25 x 14, Idp phun phu day 2mm, vat lieu kim loai nen: thep C45, vat lieu phu: nhdm hpp kim nhdm: Ni-Cr-Si-B Cdc mau dUpc phun theo bd thdng sd tdi Uu da chpn,... ket ddi vdi Idp phd cd chieu ddy 0,5nmi 4.4 Anh hudng cua thieu ket tdi cau true kim tUdng cua Idp phd - Cau true kim tUcfng cua cdc mdu trUdc xii ly nhiet cd dp xdp cao (hinh 6a) cdn cua mau sau... 2ByjDt (I) Trong do; : - Chieu day cua Idp khuech tan thay doi a b Hinh 6: Cau triic kim tuang cia Iclp phi tii hop kim nhom Ni Cr Si B a-TrU6c xii ly nhiet, b- Sau xii ly nhiet Nhtoxet: TAP CHi C