Tieu Luan Vat Lieu Xd Copy 2706

Tiu lun vt liu XDGVHD: C Nguyn Thanh Bo Nghi

( LI NI U (---oOo---

T xa n nay, ni n chn lun l vn c con ngi quan tm hng u. Bi l, mi phong tc, tp qun, sinh hot, n ung ca ta u bt u t y. T xa xa, t tin ta bit dng cc hang ng c ng v sinh sng, ri t pht kin ra nhng cch to dng cho mnh ni u tin nh bit xp chng cc khi tng thch ln nhau hay gn kt chng bng nhng cht kt dnh th c sn nh t st, thch cao, v.v chnh l nhng phng thc xy dng u tin ca con ngi. Qua cc thi k, nhu cu ca con ngi v ni li cng cao i hi vt liu lm ra phi cng c nhiu c tnh k thut tt (c bn cao hn, chng chu n mn tt, cch m, cch nhit tt, v.v). Ngoi ra, s pht trin ca x hi loi ngi cn gn lin vi s pht trin ca cng c sn xut v k thut, m vt liu l yu t quyt nh cho hai ngnh ny.

Ngy nay, vi s pht trin nh v bo ca khoa hc v k thut th vai tr ca ngnh vt liu hc cng ngy cng tr nn quan trng hn. C rt nhiu loi vt liu mi vi nhng tnh nng vt tri, c bit c ra i nhm p ng nhu cu pht trin ca khoa hc cng ngh v i sng nh vt liu p in, vt liu siu dn, v.v Tuy nhin vt liu truyn thng nh thp vn gi mt vai tr quan trng trong sn xut v i sng ca chng ta bi v so vi cc loi vt liu khc th vic sn xut ra thp vi khi lng ln l d dng, t tn km; hn na, ta c th iu chnh hm lng, phng php x l, nu luyn to ra nhiu loi thp khc nhau nhm p ng cc mc ch s dng khc nhau trong thc t.Trong cuc sng, ta d dng bt gp cc loi dng, chi tit, my mc, c ch to t thp. Tuy nhin, khng phi chi tit no cng c lm t cng mt loi thp; phi ty vo chc nng, mc ch s dng v yu cu ca chi tit cn ch to la chn loi thp cho ph hp. C nh vy th chi tit to ra mi m bo c cht lng. gip lm r hn v cc loi thp, c tnh k thut, ng dng cng nh cch bo qun thp, nhm chng em xin mang n cho cc bn ti Vt liu thp trong bi tiu lun nho nh ny!Bi thuyt trnh c th cha hon thin v cn nhiu thiu st nhng nhm chng em hy vng c c th xem xt v a ra nhiu kin ng gp khch quan bi lm c hon chnh hn.

Nhm chng em xin chn thnh cm n c!( MC LC (1( LI NI U (

2( MC LC (

4( NI DUNG (

4I.Khi nim

4II.Ngun gc

4III.Phn loi

41)Phn loi theo thnh phn ha hc

5a)Thp cacbon

5b)Thp hp kim

62)Phn loi theo mc ch

6a)Thp kt cu

6b)Thp dng c

6c)Theo tnh cht vt l c bit

73)Phn loi theo cht lng thp

7a)Thp cht lng bnh thng

7b)Thp cht lng tt

7c)Thp cht lng cao

7d)Thp cht lng cao c bit

74)Phn loi theo mc oxi ha

7a)Thp lng

7b)Thp si

8c)Thp bn lng

8IV.c tnh k thut ca thp

81)Cc thng s k thut

8a)Cu trc tinh th

8b)Thnh phn ha hc

8c)S hiu ca thp xy dng

8Thp carbon:

9Thp hp kim thp:

92)S lm vic ca thp

9a)S lm vic ca thp chu ko

9Giai on n hi:

9Giai on chy:

9Giai on cng c (ti bn):

9b)S lm vic ca thp chu nn

10c)S lm vic ca thp chu un

10Giai on n hi:

10Giai on c bin dng do:

103)Cc hin tng ph hoi

11V.Cc phng php sn xut thp

111)Phng php Bessemer

122)Phng php Martin

123)Phng php l in

13VI.ng dng ca thp

131)Thp khng g (Inox)

13a)Trong dn dng

13b)Trong cng nghip

13Cng nghip nng:

13Cng nghip nh:

142)Thp silic

143)Thp cacbon

14VII.

Bo qun thp

15VIII.Cc loi thp

151)Thp khng g (Inox)

15Ngun gc:

16B n ti sao thp li khng g:

16Phn loi:

17Cc c tnh ca nhm thp khng g Inox:

182)ng dng ca cc loi thp khng g

193)Thp Silic

19a)Khi nim

19b)c tnh

20c)Thnh phn

20d)Ch to

20e)Phn loi

20f)Thp cun Silic khng nh hng cn ngui

21ng dng:

214)Thp Carbon

21a)Khi nim

21b)Phn loi

21Theo t chc t vi v hm lng carbon trn gin trng thi Fe C:

22Theo cng dng:

22Theo phng php luyn kim:

22Theo phng php kh oxi:

22Theo hm lng carbon:

23( LI KT (

( NI DUNG (I. Khi nimThp l hp kim vi thnh phn chnh l st (Fe), vi cacbon (C), t 0,02% n 2,06% theo trng lng, v mt s nguyn t ha hc khc. Chng lm tng cng, hn ch s di chuyn ca nguyn t st trong cu trc tinh th di tc ng ca nhiu nguyn nhn khc nhau. S lng khc nhau ca cc nguyn t v t l ca chng trong thp nhm mc ch kim sot cc mc tiu cht lng nh cng, n hi, tnh d un, v sc bn ko t. Thp vi t l cacbon cao c th tng cng cng v cng lc ko t so vi st, nhng li gin v d gy hn. T l ha tan ti a ca carbon trong st l 2,06% theo trng lng ( trng thi Austenit) xy ra 1.1470C; nu lng cacbon cao hn hay nhit ha tan thp hn trong qu trnh sn xut, sn phm s l xementit c cng lc km hn. Pha trn vi cacbon cao hn 2,06% s c gang. Thp cng c phn bit vi st rn, v st rn c rt t hay khng c cacbon, thng l t hn 0,035%. Ngy nay ngi ta gi ngnh cng nghip thp (khng gi l ngnh cng nghip st v thp), nhng trong lch s, l 2 sn phm khc nhau. Ngy nay c mt vi loi thp m trong cacbon c thay th bng cc hn hp vt liu khc, v cacbon nu c, ch l khng c a chung.

II. Ngun gcTrc thi k Phc Hng ngi ta ch to thp vi nhiu phng php km hiu qu, nhng n th k 17 sau tm ra cc phng php c hiu qu hn th vic s dng thp tr nn ph bin hn. Vi vic pht minh ra quy trnh Bessemer vo gi th k 19, thp tr thnh mt loi hng ho c sn xut hng lot t tn km. Trong qu trnh sn xut cng tinh luyn tt hn nh phng php thi xy, th gi thnh sn xut cng thp ng thi tng cht lng ca kim loi. Ngy nay thp l mt trong nhng vt liu ph bin nht trn th gii v l thnh phn chnh trong xy dng, dng, cng nghip c kh. Thng thng thp c phn thnh nhiu cp bc v c cc t chc nh gi xc nhn theo chun ring.III. Phn loi1) Phn loi theo thnh phn ha hcTrong s ph thuc vo thnh phn ha hc th thp c phn loi thnh thp cacbon v thp hp kim.

a) Thp cacbonChim t trng ln nht trong tng sn lng thp (khong 80% 90%). i vi thp cacbon th theo th t c th phn thnh : SHAPE \* MERGEFORMAT

Thp cha t cacbon ,i vi thp ny th thnh phn cacbon trong thp ko vt qu 0,25%, c trng ca thp ny l do dai cao, nhng bn cng thp Thp cha cacbon trung bnh, thnh phn cacbon trong thp chim t 0,25% 0,6%. Thp ny th bn, cng cao, dng ch to cc chi tit my chu ti trng tnh v chu v p cao.

Thp nhiu cacbon, thnh phn cacbon trong thp cao hn 0,6% (ko vt qu 2,14%), thp ny dng ch to dng c ct, khun dp, dng c o lng.b) Thp hp kimC bn cao hn hn thp cacbon, nht l sau khi ti v ram. i vi thp hp kim th c th phn loi thnh: SHAPE \* MERGEFORMAT

Hp kim thp, thnh phn cc nguyn t hp kim trong thp khng vt qu 2,5%.

Hp kim trung bnh, thnh phn cc nguyn t hp kim trong thp chim t 2,5 ( 10%.

Hp kim cao, thnh phn cc nguyn t hp kim trong thp cao hn 10%.

2) Phn loi theo mc chTheo mc ch th thp c phn thnh cc nhm sau:a) Thp kt cuKhi lng ln nht. Dng sn xut, ch to cc sn phm dng trong ngnh xy dng v c kh ch to my: SHAPE \* MERGEFORMAT

b) Thp dng cCng v chng mi mn, v vy dng sn xut cc dng c ct, gt, dng c o lng, ch to khun dp. SHAPE \* MERGEFORMAT

c) Theo tnh cht vt l c bit Chng hn nh t vic xc nh tnh cht t ca thp hay l h s n di nh, m ta phn thnh: thp k thut in, Theo tnh cht ha hc t bit : chng hn nh phn thnh thp chu nng hay thp bn nng, thp ko g3) Phn loi theo cht lng thp

T s c mt ca cc tp cht c hi: lu hunh v phtpho trong thnh phn ca hn hp thp ta c th chia nh thnh cc nhm sau:a) Thp cht lng bnh thngThnh phn thp cha khong 0,06% lu hunh v 0,07% photpho trong hn hp, thp c luyn t l L D, nng sut thp cao v gi thnh r.b) Thp cht lng ttThnh phn thp cha khong 0,035% lu hynh v 0,035% photpho trong hn hp, c luyn l mactanh v l in h quang.c) Thp cht lng caoThnh phn thp cha khong 0,025% lu hynh v 0,025% photpho trong hn hp, c luyn l in h quang dng nguyn liu cht lng cao.d) Thp cht lng cao c bitThnh phn thp cha khong 0,025% phtpho v 0,015% lu hunh trong hn hp, c luyn l in h quang, sau c tinh luyn tip tc bng c chn khng, bng in x.4) Phn loi theo mc oxi ha Da vo mc oxi t thp chng ta phn loi ra cc nhm sau:a) Thp lngL thp oxi ha hon ton, thp ny cng bn, kh dp ngui, khng b r kh khi c, nhng co lm ln, khng c p lm, dng cho cc kt cu hn, thm cacbon.b) Thp siL thp oxi ha km, thp ny mm, do, d dp ngui, khng dng thp si c nh hnh v s sinh bt kh lm gim cht lng, ngoi ra cng khng c dng thp si lm chi tit thm cacbon v bn cht ht ln. SHAPE \* MERGEFORMAT

c) Thp bn lng L thp chim v tr trung gian ca 2 loi thp trn (thp lng v thp si), dng thay th cho thp si.

i vi thp phn loi theo s oxi ha th k hiu c vit sau cng ca mc thp: thp lng thng k hiu bng ch l, tuy nhin i vi thp lng th ngi ta b qua k hiu ny, thp si k hiu l ch ci: s, cn thp bn lng k hiu bng ch: n (theo k hiu Vit Nam).IV. c tnh k thut ca thp1) Cc thng s k thut

a) Cu trc tinh th

Cu trc thp (hnh 1.1) to bi:

Ferit: Fe nguyn cht, chim 99% th tch, do v mm. Ximentic: Hp cht Fe3C, cng v gin do thnh phn C. Mng peclit: Hn hp Fe v Fe3C, l mng n hi, bao quanh ferit. Mng cng dy, thp cng cng v km do.b) Thnh phn ha hc

Fe chim 99%.

C: C hm lng nh hn 1,7%. Lng C cng cao, thp c cng ln nhng gin nn kh hn v kh gia cng. Yu cu thp xy dng c: %C