Nshien ciru, Phdt triin vd Ifng dung Cons, nghi Vdt lieu (KC.02/06-10)- Hd Noi 27/11/2009
NGHIEN CUU CHE T A O THEP HOP K I M DAC BEET 03H18K9M5TK) Nguyln Tai Minh, Vu Le Hoang, Nguyln Thai Hoc
Vien cong nghe - Bo QP
Tom tit. Bai bao trinh bay kit qua nghien ciru cong nghi nau luyin, tinh luyen dien xi, xir ly nhiit chi tao vdt lieu thep hap kim dac biet cd thanh phan, td chirc va ca tinh tuong duong tiiu chuan mac 03H18K9M5TKD cua Nga. Day la thep hop kim mactenxit hod gia chua rat it cacbon (<0,03% C), cd khd ndng biin dang cao, hod bin bdng nhiit luyin vd gia cong biin dang. Vdt lieu duac sir dung di chi tao cdc chi tiit dang dng mdng, dp bin cao.
I. GIOT THIEU
Cac loai thep mactenxit hoa gia dugc sir dung nhilu trong linh vuc hang khdng, ky thuat ten lira, tau thuyln, chi tao cac chi tilt dan hdi ciia thiet bj do, trong ky thuat nhiet lanh...
Chi tilt dang dng cd chilu day 0,5 mm, lam viec trong dieu kien ap suat tdi 200 at, nhiet do cd thi len tdi 400 °C, yeu cau du bin trong khoang thdi gian ngan, da dugc lira chon che tao tir thep hgp kim dac biet - thep mactenxit hda gia mac 03H18K9M5TK).
Yeu cau ky thuat dat ra ddi vdi vat lieu de che tao chi tiet:
La thep hop kim ft ri, ft bj an mdn trong dieu kien bao quan lau dai.
Thep cd tfnh cong nghe gia cong biln dang: dap sau va miet ep tdt Cd kha nang hoa ben bang gia cong co-nhiet luyen.
Cd ca tfnh cao, gidi han bin cao (-2000 MPa) d dai nhiet dp tir nhiet dp am tdi 400 °C
Thep 03H18K9M5TK) chon sir dung dap ung cac yeu cau da neu. Day la loai thep hpp kim mactenxit hoa gia, chua rat ft cacbon (<0,03% C). Thep cd chua hai nguyen td hpp kim chinh la niken va coban. De bao dam qua trinh hda gia ciia mactenxit, thep dupe hop kim hda vdi cac nguyen td Ti, Be, Al, Nb, W, Mo.
Thep hop kim mac 03H18K9M5TK) theo tieu chuan ciia Nga tuong tu mac NIMAR125, 300 theo tieu chuan ciia Anh, My/Anh va tieu chuan ciia Dire la DIN 1.6354, thanh phan va ca tinh cho d bang 1 [5-8].
Bdng 1. Thep mactenxit hda gia ciia Nga Mac vat lieu Thanh
phan, %
Co tinh Mac vat lieu Thanh
phan, %
MPa Ro,2>
MPa
Kic, MPa.m1 / 2
A,
% z,
%
KCU, MJ/m2
KCU, MJ/m2 03H18K9M5T 18Ni 9Co
5Mo 0,9Ti
2100 1900 75-=-85 8 50 0,5 0,2 03H18K9M5TK) 18Ni 9Co
5Mo 0,9Ti 0,1A1
1910 1815 5
(5s)
Bai bao trinh bay ket qua nghien ciru va che tao thep hop kim tuong duong mac
03H18K9M5TK) bang phuong phap nau luyen trong Id cam ung trung tan, tinh luyen dien xi, tdi va hoa gia. Ket qua khao sat ca tinh va td chuc ciia vat lieu dugc danh gia va so sanh vdi vat lieu ciing loai ciia Nga.
II. QUA TRINH THUC NGHIEM
Su dung thep 08KTI (<0,8%C), niken catod (99,9%Ni), coban kim loai (99,9%Co), fero molipden (60% Mo), fero titan (30% Ti), nhdm va phu gia khac d l nau luyen.
Nghien ciru, Phdt triin va tins duns Cons nshe Vdt lieu (KC.02/06-10)- Ha Ndi 27/11/2009 Qua trinh nau luyen thuc hien trong 16 cam ung trung tan 10 kg/me va 500 kg/me. Due dien cue tieu hao cd dudng kinh $90 mm de tinh luyen dien xi.
Tinh luyen dien xi tren thilt bj dien xi DX725-N1. Xi tinh luyen mac AH$-1IT dugc nau chay lai trong Id hd quang 180 KW va do vao binh tinh luyen trudc khi dien xi.
Phdi due dien xi dugc li ddng deu hoa trong Id budng d nhiet do 950 °C, thdi gian 5 h..
Tdi d nhiet do 850 °C va hoa gia d nhiet do 490 °C thuc hien trong Id gieng P60 cd khi argon bao ve.
Phan tick thanh phan hoa hoc bang thilt bi ARL-3460 (FISONS Thuy Sy) Do dd cung tren thilt bi HP250 (Due)
Gidi han ben keo, dd dan dai dugc do tren thiet bj keo nen ZD-40 (Dire)
Chup anh td chuc te vi ciia hgp kim bang kinh hien vi quang hoc Axiovert 25 (Due), kinh hien vi dien tu quet (SEM).
HI. KET QUA VA THAO LUAN 3.1. Nau luyen che tao mac thep:
Thanh phan hoa hoc la mot trong nhung yeu td quyet dinh din tinh chat ciia vat lieu, dac biet la ddi vdi cac loai thep can xu ly nhiet de bao dam ca tinh.
Tinh toan phdi lieu me nau can cu vao he sd chay hao nguyen td tham khao va vdi ty le:
Fe 1%; Ni 0,2-0,5%; Mo 0,2-0,5%; Co 2-5%; Ti 15-20%; Al 5-10%. Nhiet dd nau luyen 1550 °C, thai gian nau luyen 40 ph.
Ket qua phan tich thanh phan hop kim nau luyen chi ra d bang 2.
Bdng 2. Thanh phan hod hoc cua thep hop kim Nguym
te
C Si S P Mn Ni Cr Mo V
% 0,0199 0,1437 0,0134 0,01 0,069 19,437 0,08 4,525 0,012 Nguym
te
Cu W Ti Sn Co Al B Nb Fe
% 0,1226 0,0337 0,869 0,001 7,463 0,004 0,001 0,01 67,18 Tir bang 2 thay rang: Ham lugng C a m e nau luyen da dat <0,03%. Sat chay hao vdi he sd -1,5%, ldn han so vdi tinh toan ban dau. Niken la nguyen td hgp kim hau nhu khdng chay hao. Co chay hao vdi ty le 7-10%, cao han nhieu so vdi du kien. Molipden hau nhu khdng chay hao. Fero titan do dua vao d dang hat nhd nen bi oxi hoa manh, chay hao 18%, can dieu chinh cap hat cho phii hop de tang hieu qua thu hdi khi hgp kim hoa. Nhdm cung chay hao manh vdi ty le 13%. Tap chdt P, S nam d gidi han cho phep <0,015%; Ham lugng Si, Mn con lai van d gidi han cao, can giam bdt.
Qua ket qua d bang 2 chii y rang: Ti, A l la hai nguyen td hgp kim hoa nham lam min hat trong qua trinh hoa gia, tao td chuc phii hop de gia cong bien dang; Day la hai nguyen td bi oxi hoa rat manh, vi vay can xac djnh che do cong nghe phu hop de bao dam thanh phan hoa hoc ciia hop kim. De bao dam thanh phan cacbon <0,03% - yeu td quan trong nhat ddi vdi loai thep nay, trudc tien phai tien hanh khu cacbon; Kha nang cao nhat khu C d 16 cam ung trung tan qua thuc nghiem dat dugc -0,3% C. Sau khi khu xong cacbon mdi tiep tuc qua trinh hop kim hoa.
Tu ket qua chi ra trong bang 2 thay rang thanh phan hoa hoc ciia hop kim nau luyen da dat mac vat lieu tuong duong mac 03H18K9M5TK) ciia Nga.
Chi dd cong nghe nau luyen thep hop kim dugc xac dinh nhu sau:
Nshien ciru. PMt trien va Ung duns Cone nshe Vdt lieu (KC.02/06-10)- Hd Noi 27/11/2009
- He s6 chay hao nguyen td: Fe 1,5%; Ni 0,2%; Mo 0,2%; Co 8,5%; Ti 18%; Al 13%.
- Nhiet dp nau luyen: 1550 °C;
- Nhiet dp hpp kim hoa: 1600 °C;
- Then gian nau luyen: 40 ph;
3.2. Tinh luyin dien xi
Xi mac AH<J>-HI cd thanh phan 95% CaF2-5% CaO dupe lua chon de tinh luyen thep cd chua cac nguyen td Ti, A l [9].
Che dp dien xi nhu sau:
Dien cue dudng kinh 90 mm, khdi lupng 100 kg - Dien ap: U= 45-r55 V; Dong dien: 1= 2000+2400 A
Tdc dp dich chuyen dien cue: 20-7-30 mm/ ph Tdc dp dich chuyin binh k i t tinh: 12-7-22 mm/ ph ap luc nude lam ngudi: 4+6 at
ap luc khi nen: 6 at
Luu lupng khi argon: 5 1/ ph Lupng xi la 10 kg
Kit qua khao sat, phan tich vat lieu trudc va sau khi tinh luyen dien xi dupe chi ra d bang 3 (a,b).
Bdng 3a. Thanh phan hod hoc ciia thep hop kim (KQ phan tich cua Z45) Nguyen td,
% C Cu Si Ti S Sn P Co
Trudc dien xi 0,0279 0,158 0,161 0,502 0,0335 0,0027 0,0139 10,62 Sau dien xi 0,0196 0,164 0,324 0,057 0,0207 0,001 0,0044 11,06 Nguyen to,
% Mn Al Ni Fe Cr Mo V
Trudc di£n xi 0,0828 0,178 15,80 67,8 0,104 4,50 0,016 Sau dien xi 0.0652 0.027 15,83 67,8 0,132 4,49 0,015
Bang 3b. Thanh phan hod hoc ciia thep hop kim sau dien xi (KQ phan tich ciia Trung tam Do luong tieu chuan Chdt lucmg Khu vuc 1)
Nguyen to, % C Si S P M n N i Cr M o
0,0171 0,3311 0,0195 0,007 0,0816 16,2736 0,2108 4,3992
NguySn to, % V Cu W T i Sn Co A l Fe
0,0157 0,1283 0,0269 0,0748 0,0004 10,521 0,0001 cBn l ' i Qua ket qua phan tich thanh phan hoa hoc trudc va sau dien xi thly ring:
- Sau dien xi, ham lupng Ti, Al giam manh. Vdi k i t qua nay cd thi cho ring: mac du cd su dung khi argon de bao ve, nhung kha nang bao ve khong hoan toan nen Ti, A l van bi oxi hoa, ddng thdi do tac dung vdi xi tinh luyen nen cd kha nang cung se lam giam ham lupng Ti Al.
- Ham lupng cac nguyen td hpp kim Ni, Co, Mo dat yeu ciu. Ham lupng C bao dam d gidi han cho phep. Ham lupng tap chat S con cao va it thay ddi do sir dung xi chua it CaO nen hieu qua khu S khdng cao.
Nghien cim. Phdt triin vd tins dune Cone nehe Vdt lieu (KC.02/06-10)- Hd Noi 2//11/2009 Vdi kit qua nay co thi thly thanh phan cua thep hgp kim sau dien xi ve ca ban dat yeu cau d l ra va tuong duong vdi mac vat lieu 03H18K9M5TK); Tuy nhien can tiep tuc nghien cuu lua chon mac xi va chi do bao ve khi tinh luyen de bao dam thanh phan Ti va Al.
3.3. Xir ly nhiet
Phdi sau dien xi dugc ii khu ung suat va ddng deu hoa trong Id budng d nhiet do 950 C. Thai gian u 5 h.
Ket qua khao sat do cung va co tinh cua thdi thep sau dien xi va ii ddng deu hoa dugc chi ra d bang 4.
Bdng 4. Kit qua khdo sat tinh chdt ciia thep sau diin xi va li
TT K l hieu D6 cung, A5, Z. KCU,
HJB MPa MPa % % kG.m/cm2
1 Mau so 1 303 1009 941 10 11 4,1
2 Mau sd 2 300 1000 931 11 12 4,3
3 Mau sd 3 310 1039 951 10,8 14 4,5
4 Mau sd 4 305 1019 960 12,7 15 4,4
5 Mau sd 5 307 1029 931 13 13 4,7
Td chuc te vi ciia thdi thep tai cac vi tri khac nhau dugc chi ra d hinh 1. Tir anh chup td chuc te vi ciia phdi thep hgp kim sau khi ii ddng deu hoa va khu ung suat nhu trinh bay d hinh 1 da cho thay: Td chuc ciia phdi thep rat ddng deu va 6n dinh d moi vi tri; Td chuc ciia thep hau nhu la ferit, cd hat da canh sang; Mau sang hoan toan. Ket qua nay da cho thay che dd dien xi, che dd nhiet va thai gian ii la phii hgp.
Hinh 1. Td chirc te vi cua thep sau dien xi vdiixlOO a, Vi tri tam thdi dien xi; b, Vi tri canh thdi diin xi Che tao phdi tam tir phdi due dien xi bang phuang phap ren ndng.
D l cai thien ca tinh va td chuc ciia thep tam nham tao trang thai phu hop cho gia cong bien dang, da tien hanh tdi d 850 °C, lam ngudi ngoai khdng khi (thudng hoa), sau dd hoa gia d 490 °C trong 3 h. Khi nung ndng de tdi, cac nguyen td hgp kim Ti, A l , Mo cd do hda tan gidi han va thay ddi trong pha ot-Fe se chuyen vao dung dich ran y va khi lam nguoi khdng cd sir tilt pha. Sau khi tdi, mactenxit ciia sat qua bao hda Ni dugc giu nguyen. Cau tnic vi md ciia thep sau khi tdi la mactenxit khdng chua cacbon. Nhd ham lugng Ni, Co cao va ham lugng C thip nen thep cd dd ben cao. Ciing vdi viec tang do ben, thep cung cd dd deo va dd dai tdt. Su hda bin ca ban dat dugc khi hda gia. Hda ben khi hda gia gan liln vdi sir tilt pha phan tan tur mactenxit, do la cac hop chat lien kim kilu Ni3Ti, NiTi, Fe2Mo, Ni3Mo. Titan va nhdm cd tac
Nshien ciru. Phdt trien va tins duns Cons nshe Vdt lieu (KC.02/06-10)- Hd Ndi 27/11/20UV dung hda ben manh nhat khi hda gia. Qua trinh hoa gia se tao cho thep cd ca tinh cao, td chuc hat min, tuy nhien do deo, dd dai ciia thep cung se giam.
Kit qua khao sat tinh chit vat lieu sau khi thudng hoa va hoa gia nhu dua ra d bang 5.
Bang 5. Kit qua khao sat ca tinh cua phdi dia sau ren, thudng hod va hod gid
TT KY hiOu §e C0ng, Ro.2, A5, z, KCU,
HB MPa MPa % % kG.m/cm2
1 7 '
MEu se 1 350 1136 6 - -
2 y
MEu se 2 345 1076 7,57
Hinh 2. Td chuc te vi cua thep sau khi ren,
x200 Hinh 3. Td chirc te vi ciia thep sau khi thudng hod, hod gid, x 200
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Hinh 4. Gian dd nhieu xa Ranghen ciia thep hap kim sau khi thudng hod, hod gia Td chuc kim tuong cua thep hop kim sau khi ren va sau khi thudng hoa, hoa gia dugc chi ra tren hinh 2 va 3.
Tir ket qua the hien tren anh td chuc t i vi cho thly td chuc ciia thep la austenit, mactenxit hoa gia. Sau khi hoa gia, td chuc hat tuong ddi min, dilu nay rat thuan loi cho qua trinh gia com? bien dans.
Nghien ciru. Phdt triin va tins duns Cons nshe Vdt lieu (KC.02/06-10)- Ha Ndi 27/11/2009 Da tien hanh phan tich rcmghen d l k i i m tra, khao sat thanh phan pha ciia hop kim trudc va sau khi thudng hoa, hoa gia. K i t qua phan tich thanh phan pha chi ra d hinh 4.
Tir k i t qua phan tich pha cho thay, trong hop kim sau khi hoa gia ngoai thanh phan Fe, Ni la chii yeu, cd xuat hien cac pha lien kim ciia Fe- Ni-Mo, day chinh la cac pha cd tac dung hda ben.
Tren gian do nhilu xa, khdng thay xuat hien cac pha lien kim ciia Ni-Ti, Ni-Al, dieu nay cd the giai thich do ham lugng Ti, A l con lai trong thep sau dien xi qua thap nen khd cd the tao pha lien kim nay; Chinh vi vay hieu qua hoa ben ciia lien kim ciia Ni-Ti, Ni-Al chac chan trong trudng hgp nay chua cao. Van de nay can tiep tuc nghien ciiu de bao dam ham lugng Ti, A l nham nang cao hieu qua hoa ben khi hoa gia ciia cac nguyen td nay.
Tir ket qua nghien cuu, khao sat tinh chat va td chuc ciia phdi thep hgp kim da cho thay chiing gan dat yeu cau chi tieu chat luong tieu chuan ciia Nga de ra. Qua thir nghiem gia cong bien dang thay rang vat lieu thep hgp kim da che tao cd kha nang dap ung tdt cho dap sau va miet ep de tao phdi dng mdng.
IV. KET LUAN
Qua kit qua thuc nghiem nau luyen che tao thep hop kim, da nit ra mot sd kit luan:
1. Che dd cong nghe nau luyen:
- Ty le chay hao cac nguyen td hop kim la: Fe 1,5%; Ni 0,2%; Mo 0,2%; Co 8,5%; Ti 18%; Al 13%.
- Nhiet do diu luyen: 1550 °C;
- Nhiet dd hgp kim hoa: 1600 °C;
Thdi gian nau luyen: 40 ph;
Vdi che dd cong nghe da xac dinh, da nau luyen dugc thep hgp kim dat thanh phan hoa hoc tuong duong mac 03H18K9M5TK) ciia Nga.
2. Tren ca sd tham khao tai lieu, qua phan tich da lua chon va bang phuang phap nau luyen hd quang da che tao dugc mac xi AH4>-1IT de dung cho dien xi tinh luyen thep hgp kim 03H18K9M5TK) it cac bon, cd chua Ti va Al. Qua ket qua phan tich, khao sat mlu thep trudc va sau dien xi cho thay thanh phan cac nguyen td hgp kim chinh khdng thay ddi, nhung ham lugng Ti, A l giam manh, dieu nay anh hudng den qua trinh tiet pha khi hoa gia, do vay can tiep tuc hoan thien mac xi de bao dam thanh phan hoa hoc ciia hop kim sau dien xi.
3. Da xac djnh dugc che dd cong nghe dien xi tinh luyen thep hop kim 03H18K9M5TK) phu hgp dung cho phdi gia cong bien dang. Da xac dinh che dd ii ddng deu hoa phu hop ddi vdi mac thep hgp kim sau dien xi. Nhiet dd ii 950 °C. Thdi gian ii 5 h.
Td chuc, cau tnic ciia thdi thep hop kim sau dien xi rat ddng deu, hat min.
4. Da xac dinh chi dd nhiet luyen phdi tam: thudng hoa d 850 °C va hoa gia d 490 °C trong 3 h. To chuc, cau tnic mactenxit cua phdi thep hop kim ddng deu, hat min. Ca tinh ciia phdi tam phii hop dung de dap vudt va miet ep.
Loi cam on
Cong trinh nay dugc thuc hien vdi su hd trg v l kinh phi ciia Chuong trinh KC.02/06-10.
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Nghien cuu, Phdt triin va Uhe duns Cons nshe Vdt lieu (KC.02/06-10)- Ha Ndi 27/11/2009
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8. JIMCTH xojioaHOKaTaHbie H3 MapTeHCHTHOCTapeiomen CTanH Mapicn 03H18K9M5TrO-BH (HC4-
BH) H 03H18K9M5TK3-HXI (HC4-H7JQ,
TexHunecKHe ycjiOBii3, TV 14-1-4805-90.
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