Ukukhethwa kwentsimbi ye-PC yokucima kunye nobushushu bomgca wokuvelisa

Ukukhethwa kokushisa kokucima kusekelwe kula manqaku alandelayo, anqunywe emva kokuqwalasela ngokubanzi.

(1) Bhekisela kwindawo ebalulekileyo ye-Ac3 yentsimbi ukukhetha ubushushu bokucima. Ukucima ukushisa kwentsimbi ye-hypoeutectoid low-alloy steel yi-30 ~ 50 ° C ngaphezu kwe-Ac3. Njengoko izinga lokufudumeza linyuka, indawo ye-Ac3 inyuka, kwaye ubushushu bayo bokucima ubushushu buyanda. Shenxisela kwi-20~50°C. Kwinkqubo yokucima i-PC yentsimbi yokucima kunye nomgca wokuvelisa ubushushu, akufuneki kuphela ukuphumeza i-austenitization ngokucinywa, kodwa eyona njongo ibaluleke kakhulu kukufumana iinkozo ezintle kunye nesakhiwo se-martensite esicinyiweyo ukuze ufumane amandla esivuno esiphezulu emva kokufudumala. , Isakhiwo se-troostite esivuthayo esinomlinganiselo ophezulu wesivuno kunye neplastiki ethile inenzuzo ekuphuculeni ukuxhatshazwa koxinzelelo lwentsimbi. Ukuze ufezekise ezi njongo zingentla, ukushisa kokucima i-PC steel kufuneka kuncitshiswe kangangoko kunokwenzeka. Ngenxa yesi sizathu, ukucima ukushisa kwe-PC yensimbi yokucima kunye nomgca wokuvelisa ubushushu kufuneka kube yi-60 ~ 100 ° C ngaphezu kwe-Ae, kunye ne-A3 yensimbi ye-PC iboniswe kwiThebhile 7-12.

Itheyibhile 7-12 Iqondo lobushushu elibalulekileyo lentsimbi yePC (ixabiso lereferensi) °C

Ibakala A lentsimbi”

30Mn 734 812

30SiMn 740 840

30MnB 732 847

35SiMn 750 830

(2) Khetha ubushushu bokucima ngokweempawu zomatshini wemveliso. Iimveliso zetsimbi zePC zineempawu zazo ngokweempawu zomatshini. Ifuna intsimbi ukuba ibe namandla esivuno esiphezulu (2 1275MPa), isivuno esiphezulu (20.05), iplastiki ethile (25%), kunye nokuchasana nokukhululeka koxinzelelo. Ezi zixhobo zomatshini ziqinisekisa ukuzinza kwexesha elide lentsimbi yePC. . Itheyibhile 7-13 kunye neTheyibhile 7-14 ibonisa iipropathi zomatshini wobushushu begumbi kwiintsimbi eziqhelekileyo zePC emva kokucima ukufudumeza okuqhelekileyo kunye nonyango olushushu. Idatha edweliswe kwitheyibhile ibonelela ngesiseko sesayensi sokuhlalutya ubudlelwane phakathi kobushushu bokucima kunye neempawu zomatshini. Ezi datha zinokubonelela ngesiseko esilandelayo.

① Njengoko ubushushu bokucima bukhula, amandla entsimbi ayancipha kwaye iplastiki iyanda. Ngoko ke, ukwandisa ubushushu bokucima kuya kunciphisa amandla esivuno kunye nomlinganiselo wesivuno, oya kuba nefuthe elingathandekiyo ekuphuculeni ukuxhathisa ukuphumla koxinzelelo.

②Ukunciphisa ngokufanelekileyo ubushushu bokucima (860 ~ 900 ° C). Inokugcina amandla esivuno esiphezulu kunye nomlinganiselo wamandla esivuno esiphezulu. Ukushisa okuphantsi kokucima kuya kunceda ukuphucula umgangatho wentsimbi, ukonga amandla, kunye nokugcina ukuxhathisa okulungileyo ekuphumleni uxinzelelo.

Ukushwankathela, ukuze ufumane iinkozo ezintle ze-austenite kunye nazo zonke izakhiwo ze-martensite ezicinyiweyo zentsimbi ye-PC, uluhlu olufanelekileyo lokucima ubushushu bomgca wemveliso yokucima kunye nokutshisa kufuneka ibe malunga ne-80 ° C ngaphezu kwe-A *. Kwintsimbi ye-silicon-ytterbium yePC, ubushushu bokucima yi-900 ukuya kuma-950°C. Ilingana nobushushu bokucima i-880 ~ 920 ° C ngexesha lokufudumeza kwendabuko.