NGHIEN CU'U-TRAO 0 6 l
V NGHIEN CU'U HAM LU'CXNG HIDRO TRONG M 6 I HAN Dg CHE TAO THU6C H A N THIEU KET HE BAZO T H A P
RESEARCH THE HYDROGEN CONTENT IN THE WELD METAL FOR PRODUCE THE AGGLOMERATED NEUTRAL FLUX
FOR SUBMERGED ARC WELDING
TS. Vii Huy Lan TrUdng Dai hge Bieh Khoa Ha Ndi
T 6 M TAT
Nghien cdu chi tao thudc hdn thiiu ket he bazd thdp (B=1.1) bdng nguyen vat lieu trong nUdc de hdn tU dong dUdi ldp thuoc cdc kit cdu thep cacbon thdp vd thep hdp kim thdp. Id vdn di khd cdp thiet trong trong linh vUc sdn xudt vdt lieu hdn. Bdi bdo ndy trinh bdy kit qud nghiin cdu dnh hUdng cua cdc yeu to chu yiu (CaF^ Ts, ts) den lUdnghidro trong mo'i hdn vd phUdng phdp xde dinh gid tri toi Uu ciia chung. Kit qud nghien cdu dd dUcfc sd dung de thiet ke thdnh phdn me lieu vd xdy dtXng quy trinh cong nghe che tao thudc hdn thieu ket he bazd thdp tUdng dUdng loai F7A (P)2 theo tieu chudn AWS A5.17-80.
Tir Ichda: Toi Uu hda; Thuoc hdn thiiu kit he bazd thdp; Thudc hdn F7A(P)2-BK; Hdm lUdng hidrd; Hdn tU dong dUdi ldp thuoc.
ABSTRACT
In this paper, the research on manufacturing the agglomerated neutral flux (B=l,l) using domestic raw materials for submerged arc welding (SAW) for the production of low-carbon steel and low-alloy steel is currently an urgent inssue manufacturing welding materials. This paper reports the results of research the influence of the factors (CaF^ Ts, ts) on the hydrogen content and were determined optimized values of the factors for the mixtures and produce manufacturing technology the agglomerated neutra flux F7A(P)2 according to AWS A5.17-80.
Keywords: Optimization; Agglomerated neutra flux; Flux F7A(P)2-BK; Hydrogen content;
Submerged arc welding (SAW). "^
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NGHIEN CLfU-TRAODPI
l.DATVANDE
Hiln nay, d nflde ta, nhieu nginh edng nghiep chi tao kit cau thep Ung dung rdng rai cdng nghe hin tfl ddng dfldi ldp thude, nen nhu cau ve thudc ban khi Idn. Tuy nhien, thudc h i n edn phai nhap khau vdi gii cao. N h i m dap flng nhu eau thi trfldng va phat trien sin xuat thuoe ban thieu kit he bazd thap d l h i n eae kit cau thep ylu cau chat Ifldng cao, bai b i o se gidi thilu kit qua nghiln cflu ve inh hfldng cua eac ylu td chu ylu (CaF,, Ts, ts) den Ifldng hidrd trong mdi h i n v i phfldng phip xac dinh gia tri tdi flu cua chflng khi san xuat thudc hin he bazd thap.
Trong sd eae tilu ehi vl chit Iflgng mdi ban ed mgt ehi tilu quan trgng l i Iflgng hidrd trong mdi ban v i vflng i n h hfldng nhilt (VAHN).
Hau hit trong cic phfldng phip b i n ndng chiy, hidro deu cd mat trong vflng hin. Hidrd trong mdi b i n ed anh hfldng tieu c\ic din tinh ban, do deo vi do dai va dap cua mdi ban chi tao tfl thep v i da sd cac kim loai va hdp kim miu nhfl Ti, Al,...
VI cd e h i inh hfldng hidrd d i trinh biy d tii hlu [2], d diy can bo sung la thuoc ban thilu kit he bazd thap ngoai ylu td d l hut am va chfla hdi am dang hidrat tUdng tU nhU thudc ban he bazd trung binh va cao, thdng thudng loai thudc ban nay cd ty 11 cic phflc chat Aluminate - Rutile eao va phin tfl nfldc cd the tdn tai d trong mang tinh t h i ben vflng efla cac phflc chat tren. Do viy, ehi do say thieu kit loai thuoe ban thilu kit he bazd thap, se khac nhilu so vdi quy trinh cdng nghe thieu kit he bazd trung binh va cao.
Muc tieu va noi dung nghien cflu:
Ngi dung nghiln eflu cac ylu td ehu ylii anh hfldng den Iflgng hidrd trong mdi han va VAHN khi che tao thudc h i n thilu ket he bazd thap, gdm cd:
-t- Chgn hdp chat dfla vao thanh phan thudc h i n va ty Ie eua nd nham ehu ddng giam lugng hidrd trong mdi ban.
+ Chgn cae thdng sd c h i do say thieu kit khi c h i tao thude han bazd thap.
• Cng dung quy hoach thUe nghiem nghiln eflu i n h hfldng cfla cac y l u td trin den ham Ifldng hidrd trong mdi hin.
+ Tdi flu hda cie y l u td trin dam bao Iflgng hidrd trong mdi ban ylu eiu.
2. DOI Tl/ONG, VAT LIEU VA PHl/ONG PHAP NGHIEN CUtJ
2.1. Ddi tUdng nghien cflu
- Ddi tugng l i thudc h i n thilu kit he bazd thap (B=l,l), tfldng dfldng vdi loai thuoc h i n F7A(P) 2 theo t i l u ehuan cua Hdi Han My AWS A5.17-80 dflde ki h i l u qui fldc la F7A(P)2-BK.
- Yeu cau Iflgng hidrd trdng mdi ban 6 mflc thap theo tilu chuan eua Viln H i n Qudcte [1,5] la H8 (H<8cmVl00g kim loai dap).
2.2. Vat lieu va thiet bi nghien cflu - Vat lieu de che tao mau ban la thep li^
ciu ban SM400B theo JIS G3106, kich thfldc Muc tilu eua nghiln cflu l i tun ra cic m i u theo tilu ehuan [5,6].
giii phap kit hgp gifla sfl dung vit lieu va cdng
nghe chi tao d l dip flng Iflgng hidrd yen cau de - Day ban dung kit hdp vdi thude ban li che tao thudc h i n thilu kit be bazd thap. EL8 theo tilu chuin AWS A5.17-80.
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NGHIEN CLfU-TRAODOI
- Thilt bi nghien eflu chu yeu:
• May ban ti^ ddng dfldi ldp thudc Dosun DZIOOO.
• Thilt bi dieu nhilt va dung cy do ciia Han Qudc de do lUdng hidrd.
2.3. PhUdng phap nghiln ciiu
Phfldng phap nghiln cUu kit hgp nghien cflu ly thuylt v i thfle nghiim.
- 0 n g dung quy hoach thfle nghiim de nghien cflu i n h hfldng cfla cie y l u td chu yeu d i n lUdng hidrd trong mdi han v i each xic dinh gia tri hgp ly cua eac yeu to.
- PhUdng phap do lugng hidrd khulch t i n trong mdi ban v i VAHN sfl dung dung dich glyxerin (C^HgO^) de nghiln cflu.
Hinh l.SddS kit cdu gd kep mdu hdn Quy trinh do Ifldng hidrd theo [5,6].
3. KE HOACH THU'C NGHlfiM 3.1. Lfla chon dang md hinh:
- Md hinh nghiln cflu cd d^ng tdng quit:
Y. = f ( X ) , i = l - ^ 3
Trong dd:
+ X - Biln dau vao la chit dfla vao t h i n h phan thude ban v i cae thdng sd e h i dd say thieu kit khi e h i tao thuoe ban.
-1- Y - H i m muc tilu la Ifldng hidrd trong mdi ban va vung i n h hfldng nhilt, emVlOOg.
- Theo cac tai lieu [1,2,4], md hinh nghiln cflu cd dang da thfle bae 2 nhfl sau:
Y = \ + bjX, + .... -t- b X + b,^X,X^ + + b„Xj^
•^..'.+ hX^\
Chgn cac bien dau vio nhfl sau:
-I- X^ - Li h i m Ifldng huynh thaeh (thinh phan chinh la CaF^) dfla vao me h l u thudc han,%;
H- X^ - Li nhilt do say thilu kit Ts, °C;
-I- Xg - Li thdi gian say thilu kit ts, ph.
3.3. Xiy dUng k l hoach thfle nghiim:
Chgn k l hoach thfle nghiem trfle giad hai mflc tdi Uu cd khoang biln thiln cua cac bien sd va ma trin thUe nghiim nhfl eae bing dfldi diy.
Bdng 1. Khodng bien thien cua cdc yeu to'
Cac bi£n so Miic tren Mdc ccf scr Miic dildi Klioang bien thien
Bi^n thiic CaF J, (%) Z, 14 10 6
4 T, CO
Z, 700 600 500
100 t , (phut)
80 60 40
20
Bien ma hoa
X, +1 0 - 1
X j
+1 0 - 1
X j
+1 0 - 1
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NGHieN CLfU - T R A O D O I
V6i Z - Cac bien so thijc, % khoi luong.
X - Cac bien so ma hoa (khong thil nguyen).
Bdng 2: Bang ke hoach thdc nghiem vd ket qud thi nghiim
N«thi nghidm
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Gia t r i cac bi^n thUc Zi.
CaF,,%
6 14 6 14
6 14 6 14 5,14 14,86 10 10 10 10 10 10 10
z=.
T,°C 500 500 700 700 500 500 700 700 600 600 478,5 721,5 600 600 600 600 600
z..
t, p h i i t 40 40 40 40 80 80 80 80 60 60 60 60 35.7 84.3 60 60 60
Gia t r i cac M e n m a l i o a
X, - 1 +1 - 1 +1 - 1 +1 - 1 +1 - 1,215 + 1,215
0 0 0 0 0 0 0
X , - 1 - 1 +1 +1 - 1 - 1 +1 +1 0 0 - 1,215 + 1,215
0 0 0 0 0
X , - 1
^ 1 - 1 - 1 +1 +1 +1 +1 0 0 0 0 - 1,215 + 1,215
0 0 0
H a m m u c t i e u (lUtfng liidr6 t r o n g m o i h a n ) Y, H j , cmVlOOg
6,2 5,0 4,6
3,3 J 5,5 1 4,4 J 3,7 "1 2,5
5,2 2,9 5,7 2,8 4,5 3,1 3,3 3,4 3,2
Lfldng hidrd trong kim loai mdi ban vi VAHN thfle hien bang phfldng p h i p glyxerin va quy trinh kiem tra khi hidrd trong mdi h i n [5,6] d Cdng ty Cd p h i n Q u e ban d i l n ViltDiic (VIWELCO). Cac kit qui thi nghiem sau khi xfl ly loai bd nhflng sd lieu chUa sai sd thd, gia tri trung binh efla cac thi nghiim dflde d i n ra d bang tren.
3.4. Tien hanh thi nghiim
Cac thi nghiem dflde thfle hiln vdi ehe do ban nhfl bang sau:
Bdng 3. Cdc thdng so chi do hdn Di(dng k i n h
day ban, m m 4,0
Gia tri cac t h d n g s6 c h i d o h a n Cfldng do dong
d i l n ban I , A 650
Dien ap han U K - V
28
Van toe h a n V^,cm/ph
45
Tam vdi dien cUc, m m
25 G d c nghieng dien cflc
0
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NGHIEN CCrU-TRAO D O I
Hmh 2. Mdu da hdn
Mau sau khi ban se tiin h i n h do Ifldng hidrd trong mdi h i n bang phfldng phap Glyxerin tai Phdng Thi nghiim Cdng ty Cd phan Que h i n dien Viet Dfle. Sau 72 gid khi hidrd thoit ra tren binh chia do, do dflde the tich V(ml).
Hinh 3. Mdu sau hdn ngdm trong nUdc dd
Kit qua cudi cung la trung bmh cdng cua 3 thi nghiim sdng sdng cho eae sd lieu thi nghiim.
4. KET QUA VA THAO L U A N
4.1. Xay dflng phUdng trinh hoi quy Xfl ly eic so lieu thi nghiim bang p h i n m i m chuyin dung n h i n dugc phfldng trinh boi quy sau diy:
H^ = 3,416 - 0,574X, - 0,795Xj - 0,355X3 - 0,017X^Xj + 0,017X^X3 - 0,034X^X3 + 0.241Xj^ -1-
0,327X/-H 0,133X3^ (2) HI sd tfldng quan: R^ = 0,966.
MUc do tfldng thich efla phfldng trinh hdi qui eao.
4.2. Bieu diln cac dUdng d?c tinh
Tfl phUdng trinh hdi quy bieu diln cae dudng die tinh nhfl sau:
- Anh hfldng efla ham lUgng CaF^ (%) trong thudc h i n den lUdng hidrd trong mdi ban.
[H], a n V l O O g
Hinh 4. Mdu thd ddt trong binh gom kh'hidrd gia •___—,_____^_ . , , , , , '" "', I trons mdy diiu nhiit '' < • > ' • > ' «' i> c n 14
* -^ • C a F ; , H
LUdng hidrd trong 100(g) kim loai mdi Hmh 5. LUdng hidrd trong moi hdn phu thupc vdo h i n dUdc tinh theo edng thfle: C«F^ (%) vdi T=600°C. t=60ph
V x 8 5 ^ 5
" T ; T: T" i , ' ^ Qua do thi cho thay h i m lugng CaF^
H = —zrhrz ^^^ '•^^§ ^^^ lugng hidrd trong mdi ban se giam rat 0 , 7 9 rd. Vdi T =600''C, t=60ph giai doan dau khi h i m ^
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NGHIEN CLTU -TRAOOOl
Iflgng CaF, dfla vio tfl 11 - 1 4 % thi mflc do giam Thdi gian siy anh hfldng ylu hdn hai ye'u manh. Dilu nay, cd t h i dflde giai thich tic dung td trin.
quan trgng cua huynh thaeh.
- Anh hfldng cua nhilt do siy thilu kit thuoc ban din Iflgng hidrd trong mdi han:
- Sfl phu thudc cua Ifldng hidrd trong moi ban vao cac ylu to dang 3D:
-I- Anh hfldng dong thdi eua nhi?t dO say thilu kit va thdi gian say thieu ket den hi(fD^
hidro trong mdi b i n v i VAHN vdi ham lugng CaF, khdng doi ed dang sau day.
Hinh 6. LUdng hidrd trong moi hdn phu thupc vdo nhiet dp thieu kit vdi CaF^ ^10%. t=60ph
Dac tinh cua dd thi chd thay khi nhiet do say thilu kit tang thi Ifldng hidrd trong mdi h i n se giam manh, Iflgng hidrd trong mdi ban se tilm cin khi nhilt do say tang din khoang 670-^710°C, eho thay nhiet do thieu kit tdi thilu tfl 680°C. Diy l i ed sd quan trgng d l xic lap chi do say thilu kit trong phan Ifla chgn che do say thilu kit hgp ly sau nay.
- Anh hfldng cua thdi gian say thilu kit thudc h i n din Ifldng hidrd trong mdi hin:
Hinh 7. Luang hidrd trong moi hdn phu thupc vdo thdi gian say vdi CaF^ =10%, T^600°C
Hinh 7 LUdnghidro trong moi hdnphif thupc vdo nhiit dp vd thdi gian say vdi CaFy=10%
+ Anh hfldng ddng thdi cfla ham Iflcing CaF^ v i nhiet do say thieu kit d i n Iflgng hidrfl trong mdi b i n va VAHN, vdi thdi gian say thi^
kit ed dinh, ed dang dfldi day:
I LUdng hidrd trong moi hdn phu thupc vao CaF^ (%) vd nhiet dp say vdi t = 60ph
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NGHIEN CU'U-TRAO D 6 |
- Su phu thuge cua lUgng hidrd trong moi han vao cie yeu td dang giin do dang mflc:
500 600 700 800 Ts, oC
Hmh 9. Gidn do ddng miic xac dinh hdm lUdng H^
trong moi hdn vdi CaF = 10%
- Dilu kiln ring huge va ham muc tilu dflde ebon de tdi Uu xuat phit tfl yeu cau cu the ddi vdi loai thudc ban F7A(P)2-BK can dap flng eic dieu kien lugng hidrd thap sau day:
Y = H j < 8 c m V l 0 0 g 4.4.2. Ket qud toi Uu
Giii bai t o i n tdi Uu vdi cac dilu kiln rang huge n l u t r i n bang phan mem tdi flu eho kit qua nhu sau:
H a m l u o n g hu>iih thaeh, nhiet d o s^y thieu ket va thol gian s^y thieu k H CaF2. %
6,34 6,5
Ts, °C 794 790
ts, phut 41 41
H j , cmVlOOg 5,03 5,26
500 600 700 800 Ts, oC
Hinh 10. Gidn do dang mUc xac dinh lUdng H^ trong moi hdn vdt t = 80ph
Dang gian do nay thuan tien trong viec xac dinh c b l do thilu kit trong thfle t l s i n xuit thude b i n .
4.3. Xac dinh h a m lUdng toi Uu
4.4.1. Cdc dieu kien rdng bugc vd hdm toi Uu Dilu kien tfldng minh la gidi h^n cfla eac bien dau vao:
6 % < XJ = CaFj < 14 %;
500 °C < X, < 800 "C;
40ph < X3 < BOph.
- Sd lieu ddng 1 la thed ket qua tdi flu.
- Sd h l u dong thfl 2 la kit q u i kiem tra.
Sfl sai lech so vdi gia tri tinh toan dUdi 10% v i nam trong pham vi cho phep vdi loai thudc ban F7A(P)2.
4.4. Thao luan
Tfl cac kit qui thu dflgc dang cae phfldng trinh bdi qui va dang cac dfldng die tinh ed t b I rut ra nhflng kit luan quan trgng sau diy:
- Cac phfldng trinh hdi quy ed do tfldng thich eao R^=0,966, dae tinh anh hfldng cua cie ylu td dau vao din Ifldng hidrd trong mdi ban cua thudc h i n he bazd thap rat rd.
- D l giam Iflgng hidrd trong moi h i n thi h i m Ifldng huynh thaeh va gia tri nhiet do say, thdi gian say phai dat den gii tri ngfldng nhat
dinh. ^
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NGHIEN CLfU - TRAO OQl
5. KET LUAN
- Cong trinh da nghien ciJu anh hilcmg cua cac yeu to c h i yeu iSn luong hidro trong moi hin.
- Xay dung cac quan he dinh lUdng va dUa ra dUac cac phuong phap xac dinh duoc tyl{
huynh thaeh can dUa vao me Ueu thuoc ban va che do say thieu ket gom, nhiet do va thdi gian thieu Icet de san xuat thuoc ban thieu ket he bazo thap F7A(P)2-BK.
- Tii cac d u t o g dac tinh cho thay ngudng anh hudng ro net den lilong hidro trong moi han la nhiet do tren 680°C, khi do hieu qua tang ham lilong huynh thaeh va thdi gian say mdi thilc sil pbat huy tac dung.
- Xay dung duoc cac gian do dang mile de xac dinh luong H^ trong moi han, giiip cac chuyjn gia ky thuat ling dung thuan tien vao viec dieu chinh tbanh phan huynh thaeh va che do thieu ke'l khi luong hidro yeu cau thay doi.
- Trong cong trmh nay da xac dinh duoc ham luong huynh thaeh va che do say thieu ket hop ly de san xuat thuoc han thieu ket be bazO thap F7A{P)2-BK.'>
Ngay n b | n bai: 23/02/2016 Ngay phan bien: 11/3/2016
Tai li£u tham khao:
[1]. VO Huy Lan, Bui TOn Hanh (2010); Giao trinh Vdt lieu han, NXB. Bach Khoa Ha NOi.
[2]. Vu Huy Lan, Tran Xuan Trung (2015); Ng/ife«ci?u/i(]m lUdnghidro trong mot hdn khi che tao thuochitl thieu ket hi bazd cao. Tap chi Co khi Viet Nam, so 8/2015, tr. 89-96.
[3]. Nguyen Minh Tuyen (2005); Quy hoach thUc nghiem, NXB. Khoa hpc va Ky thuat. Ha Noi.
[4]. HoTanoBa H.H., (1989), CeapoHUbte Mamepuajiu dnit dyzoeou ceapKU. MaiuHHocxpoeHHe, MocKsa.
[5]. ISO 3690:2000, Welding and allied processes ~ Determination ofhyidrogen content inferritic steel arc weld metal.
[6]. VIWELCO (2008); Quy trinfe kiem tra khi hidro trong moi hdn.
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