Nghiên cứu nấu luyện mác thép 30crmnsi từ nguyên liệu sắt xốp trong lò cảm ứng

Nguyin T r u ^ g An', Nguyen Manh Tien', Nguyin Quoc Vift^ 'Kfaoa Co khi, Hpc vien Ky thudt Qudn sv ^Vien Ky thudt Co gidi Qudn su, Tdng cue Ky thuat T 6 M TAT Bdi bdo trinh bdy kit qud

NGHlfeN CUtJ NAU LUYEN MAC THEP 30CrMnSi TU" NGUYEN / LIEU SAT X 6 P T R O N G L 6 CAM UTVG

STUDY ON MELTING 30CrMnSi STEEL FROM SPONGE IRON

IN INDUCTION FURNACE

TS Nguyin T r u ^ g An', Nguyen Manh Tien', Nguyin Quoc Vift^

'Kfaoa Co khi, Hpc vien Ky thudt Qudn sv

^Vien Ky thudt Co gidi Qudn su, Tdng cue Ky thuat

T 6 M TAT

Bdi bdo trinh bdy kit qud nghien ciru ndu luyen mdc thep 30CrMnSi tir nguyen lipu sdt xop dat yeu cdu v&i thdnh phan tugng duang mdc 30XrC, theo tieu chudn FOCT 4543-71 Kit qud nghien ciht cho thdy sat xop Id nguyen Hpu sqch co hdm lugng P% vd S% thdp co the su di^ng de che tgo cdc sdn phdm quoc phong vd cdc ngdnh kinh te khdc

Tir khda: Sat xop, thep 30CrMnSi, to chirc te vi 16 cdm img

ABSTRACT

This paper presents the research results practicing 30CrMnSi steel from sponge iron equivalent grade SOXTC (TOCT 4543-71) Tlie study results confirmed, sponge iron is clean materials content S%, P% lower, can be used to manufijcture defense products and other economic sectors

Keywords: Sponge iron; steels 30CrMnSi, microstructure, induction furnaces

1 DJ^T VAN DE cdng Mdc thep dupc sd dyng rpng rai de che

tao cdc chi tiet true, bdnh rang, sdn xudt d td, Thep 30CrMnSi la mac thep thupc mdy keo, cdc may mdc ddn dung va cdc trang

hp thep hpp kim thap, dp ben cao Thep cd bi qudn sir dac biet la su dyng ldm cdc cfai tidt ham lupng C% trung binfa vd tdng fadm lupng cho cdc (oai vu khi vd ten lira,

nguyen td hpp kim cung d phgm vi trung binh

Cdc nguyen td hpp kim tfaupc dang nguyen td Viec nau luypn mdc tfaep vdi vat lipu thdng dung, khdng ddt vd de kiem Mdc thep gang vd thep phe da dupc nfaieu nhd mdy sdn nay cho co tinh tdng hpp tot, cd nguyen td cho xudt, tuy nhien, de Iuyen dupc mdc thep cd ham

dp thdm tdi tot, cd nguyen td fada b§n Ferrit lupng tap cfadt thdp, P, S thdp, khi thap, phdi sii Idm tdng dp bdn, cd tinh deo trung binfa, dl gia dung cdng ngfae pfauc tap vd tdn kdm, kfad kfaan ^

ISSN 0866 - 7056 TAP CHf CO KHi VtET NAM, Sd 10 ndm 2016

NGHltN CU'U - TRAO D O I

Ben canh do, ciing chua co nha miy nio t?o sin

phim mang tinh thucrng phim Hien nay, nhct

CO sit xdp, mgt nguyen lieu sach ham lugng tap

chit thip, P, S thip, chiia mgt lugng oxy nhit

djnh, dugc luyen trong 16 cim ung c6 ttoh nang

soi, khuiy dio nuoc thep tao thuan lgi cho viec

khu tap chit Theo tii lieu [2], cho thiy, cic

mic thep dugc luyen tu sit x6p dat yeu cau ve

thinh phan nhung tinh nang ca hgc lai vugt trOi

so vdi mic thep cimg loai dugc luyen tir 100%

thep phi

Do vgy, viec nghien cuu thuc nghiem

luygn mic thep 30CrMnSi bing nguyen ligu sat

x6p Mirex trong 16 cim inig de tao ra mic thep

30CrMnSi c6 hira lugng P, S < 0.035 li cip

thik

2 NOI DUNG NGHrtN c t r u

2.1 Trlnh tyr tiln hinh thirc nghigm

Qui trinh nghien cuu thuc nghigm dugc

tien hinh bao g6m cic buoc theo trinh ttr nhu

tren hinh 1, bao g5m: Chuin bj ph6i ligu va thiit bi niu luyen; tien hanh niu luygn, hgp kim hoa va diSu chinh thanh phin; r6t diic phoi; kiim tra thinh phin va xic djnh to chiic phoi due

*

Niu I q * tnng l6cioidig,to kmbii.(liiii * RMdKffam * KinitiftiA

Hinh l.Sadd cdc bu&c lien hdnh thifc nghigm

2.2 Chuin bi nguySn vat li^u

Qui trinh niu luyen dugc thuc hi^n tji Nhi miy thugc Cong ty C6 phin Khoing sin

vi Luygn kun Vigt Nam (MIREX) dp tai Cao Bing Tiin hinh tinh toin ph6i li$u theo ty if khdi lugng giiia sit x6p vi th^p phe li 30:70%,-khdi lugng cy the dugc tinh toin khi niu trong

16 cim umg 1 tin Nguyen ligu sat xop do Mirex Cao Bing cung cip dugc kiim tra vi tr^g thii

vi thinh phin nhu tbing 1 Thep phi vi fero dim bio yeu ciu nhu bing 2 vi dugc chuin bj

vi kich thu6c de thuin den cho qui Ixinh nau

Bdng 1 Nguyen lieu sdt xdp dugc sdy kho vdkiSm tra thdnh phan [1]

Thinh phin cic nguySn t i (%) Tong sit

86^92

SSt kim lo^i

80-82

C

<0,3

P

<0.03

S

<0.03

Con lai FeO, NTHK

Co hgt (mm) 12+34

Bdng2 Thdnhphdn thep phe vd fero

Nguyen ll^u

Thep ph6 CT3

FeMnSO (cicbon thap)

FeSi75

FeCr65

T h i n h p h i n hoi hgc (%)

C 0,12 0.015 0.015 0,025

Si 0,18 1,45

70 4,0

Mn 0,39

68

-C r

<0,3

-60-65

P 0,04 0.3 0.03 0,04

S 0,045 0.03 0.02 0.03

Ket qui tinh toin phii lieu dii voi cic nguySn liSu cin thiit cho mdt lin niu tren 16 1 tin dugc thing ke nhu bing 3

ISSN 0866-7056 TAP CHl CO KHl V I £ T NAM, S5 10 nim 2016

NGHIEN C U U - TRAO DOI

Bang 3: Bdng tinh todn phoi lieu mdc thep nghien cuu

TT

1

2

3

4

5

6

NguySn Il^a

sit xop

Th^pheCT3

FeMnSO

FeSi75

FeCi65

Nhomday

Khoi lirgng (kg)

334

773

13

15

13 1,5

TT

7

8

9

10

11

Nguygn li^u Than vun CaO

CaFj

Dong

Ni

Khoi lirgng (kg) 3,5

5

3

2

2

Trong qua trinfa ndu luypn, de dilu

cfainfa thdnh phan cua mac thep, tidn hdnfa viec

Idem tra nhanh tfaanfa phdn fada hpc, qua trinh

rdt diic dupc tfauc faipn trong khudn due dutng

2.3 NSU luy^n vd rdt due phdi thep

-* Qud trinh ndu luyfn dugc tiin fadnh tren

Id cdm dng 1 t ^ (hinh 2-a), yeu cau chudn bj

day du vd nguygn lipu Id (ddm Id, kiem tra ho&t

dpng cua Id, ) vd dyng c\i ndu luypn Trudc

hdt th\rc hipn Idt ndi Id: Ikg (CaO/CaFj:!/5)

Tfadp pfad CT3 dupc xep khit vdo Id, cdc cyc

lieu cd kich tfaude ldn dupc xep sdt tudng Id

noi t^p trung nfaipt cao nfadt Nang dan cdng

su^t khodng 80% cdng sudt dinh muc cho den

khi thdp phe chdy faet Kfai lieu da cfady faet tien

fadnfa hg cdng sudt Id xudng kfaodng 50% vd duy

tri de ngp lipu sat xdp

Hinh 2 Thiit bi nau luyin vd kiim tra nhanh

thdnh phdn:

a) Ld cdm img I tdn: b) Mdy phdn tich thdnhphdn

Q4 Tasan 170

sit xdp cin dugc say khd vi dugc nap lim nhiiu dot, mdidgt5kg,khdngdisitxdpndi tren bi mat xi, duy tri chiiu day ldp xi khoing lOmm, nap hit so lugng sit xip khoing 5 phut thi nang cdng suit 16 len 80% Quan sit lieu nap da chiy hit tien hinh vdt xi, tao xi lan 2 vdi lugng khoing 1kg CaCH-CaFj Sau khoing 2-3 phut di xi chiy ldng Trong qui trinh nap ligu sit xop vi thep phi kit hgp khii P Can t?o xi mdi khii P, cd dg Bazo B = 3, cho mgt lugng nhit dinh oxit sit vdi trgng lugng chiem khoing 14-18% trpng lugng xi, duy tri nhigt dg

Id dkhoing 1300-I350»C; BChdi lugng xi nap ty

lg vdi lugng P cin khii, xi/P = 35-^50 lan, nhxmg khdng qui 1,5% trgng lugng me niu

Sau khi nap ligu xong, tiin hinh khii S

vi khii khi De khii S tien hinh sau khi khOr khi, tao xi mdi khu S, dp Bazo B = 6, ning cdng suit

Id Ifin de nhigt d0 nudc thep khoing khoing 1650°C; khdi lugng xi nap ty lg vdi lugng S cin khu, xi/S =10 - 20 lin, nhung khdng qui 1,5% trgng lugng me niu Tiip theo dung FeMnSO + FeSi75 + Al vdi ty le: 1,5:1,5:0,8 de khu khi N?p theo thu t\r FeMn - • FeSi -> Al Tiin hanh lay miu thfip lin 1 vi phan tich nhanh thinh phan tren miy Q4 Tasan 170 (hinh 2-b)

Tren co sd kit qui phan tich thinh phin hda hgc, tinh toan cic thinh phin hgp kim hda

vi dieu chinh thinh phan cacbon theo ty lg hao chiy ly thuyet Qui trinh hgp kim hda dugc tiin

hinh theo thii tu: FeMn —> FeSi, FeCr Dimg "

ISSN 0866-7056

TAP CHl CO KHl VIETNAM, Sd 10 nim 2016

NGHieNCCrU-TRAODOl

than dien c\rc de dieu chinfa hdm lupng C Khi

hpp kim hda chu y ha thdp nhiet dp nudc thep

Tien hanh Idy mdu de phdn tich nfaanfa tfaanfa

pfadn ldn 2, so sdnh cdc thdnh phdn co bdn vdi

yeu cdu de tinfa todn dieu cfainfa Qua trinh ndy

lap iai ddn khi cdc thdnh phdn nam trong gidi hgn, cy the den lan kiem tra va dieu chJnh thu 4 thi dgt dupc cdc yeu cau Ket qud cdc ldn phdn ticfa nfaanh thanh phdn dupc thdng ke trong bdng 4

XT

1

2

3

4

Bdng 4 Kit qui: cdc ldn phdn tich nhanh thdnhphdn hda hgc

IJ

Thanh phin cic nguyen thip 30CrMnSi (%) |

C

0.130

0.231

0.272

0.279

Si

0.0067

0.4480

0.9510

0.9260

Mn 0.024 0.576 0.825 0.920

P 0.020 0.022 0.024 0.023

S 0.020 0.023 0.022 0.018

Cr 0.110 0.561 0.863 0.936

Mo 0.0160 0.0096 0.0120 0.0080

Ni 0.024 0.151 0.155 0.158

Cu 0.042 0.166 0.165 0.170

Al 1

1.02 0.473

0.486 •'

0126

1

Thep nau xong dugc rdt trvc tiip vio khuon kim loai, cho 0,lkG Al vio mdi gau rdt di khii

khi Kich thudc, ket ciu khudn diic diing vi sin phim sau khi due dugc trinh biy trong hmh 3

T ~ l

^ • p

|«ioo| 1

1 axo

i

Htnh 3 Sdn phdm due vd ket cdu khuon:

a) Kich thuac khudn: b) Khuon due ddng: e) Phdi sau khi due dimg

3 P H A N TiCH K £ T Q U A THVC NGHIEM

De kiim tra sin phim sau khi niu diic mic th6p tai Cao Bing, tiin hinh liy 4 miu th^p (tai

cac V, tn va thd, diem khic nhau), ki higu nhu tren hinh 4 Tiin hinh xic dinh thinh phin hda hgc

va to chuc tai Tnmg tam Bo ludng, Vign Cdng nghg Tdng cyc Cdng nghigp Qudc phdng

Hinh 4 Mdu thep chudn bi khdo sdt thdnh phdn vd Id ehirc

ISSN 0866.7056

T4PCHlcaKHlVl£TNAM,Sd 10nam2016

NGHIEN CO-U-TRAO D 6 I

3.1 Thinh phin hda bgc

Thinh phin hda hgc dugc phan tich tren thiit bi SpectroLab model LAB LAVMI1 (hinh 5-a), kit qui dugc tdng hgp va so sinh vdi mic thep tuong duong SOXTC (TOCT 4543-71) nhu tren bing 5

Bdng 5 Thdnh phdn hda hgc mdc thep nghiin euu 30CrMnSi

Mic thep

30CrMnSi (Nau luygn)

30XrC (TOCT 4543-71)

Thinh phin hoa hoc (% khii lugng)

C 0,302 0.28-0,35

Mn 0,978 0,80-1,10

Si 1,09 0,90-1,20

Cr 0,989 0,80-1,10

Ni 0,231

<0,3

P 0,022

S 0,0145

<0,035

Tu ket qud trong bdng 5 cho thdy: Mdc thep nghien dm Iuyen tu sdt xdp cd thdnh phan Si%,

Mn%, C% ddu ndm trong gidi faan So vdi mdc tfaep 30CrMnSi tieu cfaudn TOCT 4543-71 tfaanfa phdn tgp chdt thdp hon nhieu 0,022%P; 0,0145%S

Hinh 5 Thiet bi xdc dinh thdnh phdn vd id chitc phoi thep nghien cdu:

a) Thiet bi phdn tich thdnhphdn SpectroLab model LAB LAVMH: b) Kinh hien vi soi kim tucmg AXIO Dim

3.2 T 6 chirc cua th6p

Td chuc cua mau tfaep SOCrMnSi dupc xdc dinfa tren kinfa hien vi soi kim tuong AXIO Dim

(hinh 5-b) Kht qud xdc dinh to chuc te vi ciia cdc mdu nhu hmfa 6

Hinh 6 Td chirc te vi mdu thep nghien ciiu:

a) Mau 1 x50 lan; b) Mau 2 x 100 lan; c) Mau 3 xlOO ldn: d) Mdu 4 x200 lan

ISSN 0866 - 7056

TAP CHi CO KHf VI$T NAM Sd 10 nam 2016

Theo kit qui nhu tren hmh 6, nhin thiy mac thep dugc nghien cliu cd co h?t trung bhih khoing 50pm, phii hgp vdi td chiic diic mac thep [4]

4 NHAN XET VA KET LU^LN

sit xdp li mgt phin quan ttgng trong qua trinh luygn thep chit lugng cao, thep nau luygn tit

sit xop cd him lugng tap chit P%, S% thip dudi 0.025 mi chua cin qua tinh luygn

Kit qui nghien ciiu cd thi khing dinh viec luygn ihip 30CrMnSi tu sit xdp cd d Vigt Nam ^

li hoin toin thuc hign dugc, kit qui tuong duomg mic thep 30XrC theo TOCT 4543 -71 cua Lien

bang Nga Kit qui niy li co sd cho vice chu dgng tao ra v^t ligu phuc vu cho cdng nghiep quoc

phdng vi cic nginh kinh te khic tii nguyen lieu sit xdp cho mac 30CrMnSi va dinh hudng cho cac loai hgp kim khic •

Ngiy nhjn bii: 12/9/2016

Ngiy phin bign: 15/10/2016

Tii ligu tham khio:

[ 1 ] Tira chudn ea sd sdt xdp MIREX, Cao Bing 2012

[2] KS Nguyen Nggc Linh, KS Phan Thanh Binh, KS Trin Van Doin, PGS, TS Dinh Bi Trg; Cdc kit ' qud nghien ciru ung dgng vi sdn xudt sdt xdp Mirex vd thep hgp kim, Hgi nghi Co khi toin quoc, 2012, [3] T Senthilkumar, T K Ajiboye, Effect of Heat TYeatment Processes on the Mechanical Properties of Medium Carbon Steel, 2012

[4], ripoKar coprOBOH, KajmOpoBauHLiii, co cneuHanbHoii OTitejucoH noeepxHOcni H3 yraepoflHcrofi Ka^ecTBeHHOH crajin

ISSN 0866-7056 TAP CHf CO KHI VIET NAM, Si lOnam 2016