Binciken Ƙirƙirar Ƙirƙira da Tsagewar Rarraba Phosphorus a Ƙarfe Tsarin Carbon

Binciken Ƙirƙirar Ƙirƙira da Tsagewar Rarraba Phosphorus a Ƙarfe Tsarin Carbon

A halin yanzu, da na kowa bayani dalla-dalla na carbon tsarin karfe waya sanduna da sanduna bayar da gida karfe Mills ne φ5.5-φ45, da kuma mafi girma kewayon ne φ6.5-φ30.Akwai hatsarori masu inganci da yawa da ke haifar da wariyar sinadarin phosphorus a cikin ƙananan sandar waya da albarkatun ƙasa.Bari muyi magana game da tasirin rarrabuwar phosphorus da kuma nazarin samuwar fasa don tunani.

Ƙarin phosphorus zuwa ƙarfe na iya daidai da rufe yankin austenite a cikin zane-zane na ƙarfe-carbon.Saboda haka, nisa tsakanin solidus da liquidus dole ne a kara girma.Lokacin da aka sanyaya ƙarfe mai ɗauke da phosphorus daga ruwa zuwa ƙarfi, yana buƙatar wucewa ta kewayon zafin jiki mai faɗi.Yawan yaɗuwar phosphorus a cikin ƙarfe yana jinkirin.A wannan lokacin, baƙin ƙarfe mai narkewa tare da babban ma'aunin phosphorus (ƙananan narkewa) yana cika a cikin ramukan da ke tsakanin dendrites na farko da aka ƙarfafa, wanda hakan ya haifar da rabuwar phosphorus.

A cikin yanayin sanyi ko tsarin extrusion mai sanyi, ana ganin samfuran fashe sau da yawa.Binciken metallographic da bincike na samfuran fashe ya nuna cewa an rarraba ferrite da pearlite a cikin makada, kuma ana iya ganin tsiri na farin ƙarfe a cikin matrix.A cikin ferrite, akwai nau'ikan sulfide mai haske mai siffa mai tsaka-tsaki akan wannan matrix ferrite mai siffar band.Wannan tsari mai siffar bandeji wanda ya haifar da rabuwar sulfur phosphide ana kiransa "layin fatalwa".Wannan shi ne saboda yankin da ke da sinadarin phosphorus a cikin yankin da ke da mummunar rabuwar phosphorus ya bayyana fari da haske.Saboda yawan sinadarin phosphorus na farin bel mai haske, sinadarin carbon da ke cikin farin bel mai haske da mai haske yana raguwa ko kuma abin da ke cikin carbon ya yi ƙanƙanta.Ta wannan hanyar, lu'ulu'u na ginshiƙan dutsen simintin gyare-gyare na ci gaba da haɓaka zuwa tsakiya yayin ci gaba da yin simintin bel mai wadatar phosphorus..Lokacin da billet ya ƙarfafa, austenite dendrites suna fara hakowa daga narkakken ƙarfe.Phosphorus da sulfur da ke cikin waɗannan dendrites sun ragu, amma ƙarfe mai ƙarfi na ƙarshe yana da wadataccen sinadarin phosphorus da sulfur najasa, wanda ke ƙarfafa a Tsakanin axis dendrite, saboda yawan abun ciki na phosphorus da sulfur, sulfur zai samar da sulfide. phosphorus za a narkar da a cikin matrix.Ba shi da sauƙin watsawa kuma yana da tasirin fitar da carbon.Ba za a iya narkar da carbon a ciki ba, don haka a kusa da maganin phosphorus (Gani na farin band ferrite) suna da babban abun ciki na carbon.Sinadarin Carbon a ɓangarorin biyu na bel ɗin ferrite, wato, a ɓangarorin biyu na yankin da ke da wadatar phosphorus, bi da bi ya samar da ƙunƙuntaccen bel ɗin lu'u-lu'u mai tsaka-tsaki da bel ɗin farin ferrite, da nama na al'ada dabam dabam.Lokacin da billet ɗin ya yi zafi kuma aka danna, ramukan za su shimfiɗa tare da hanyar sarrafa birgima.Daidai ne saboda rukunin ferrite ya ƙunshi babban phosphorus, wato, babban rarrabuwar phosphorus yana haifar da samuwar babban tsari mai faɗi da haske na ferrite, tare da baƙin ƙarfe a bayyane Akwai launin toka mai launin toka na sulfide a cikin fage mai haske da haske. kashi jiki.Wannan rukunin ferrite mai arzikin phosphorus mai dogayen tsiri na sulfide shine abin da muke kira ƙungiyar “fatalwa line” (duba Hoto 1-2).

Binciken Ƙirƙirar Ƙirƙira da Tsagewar Rarraba Phosphorus a Ƙarfe Tsarin Carbon02
Hoto 1 Fatalwa waya a cikin carbon karfe SWRCH35K 200X

Binciken Ƙirƙirar Ƙirƙira da Tsagewar Rarraba Phosphorus a Ƙarfe Tsarin Carbon01
Hoto 2 Wayar fatalwa a cikin karafan carbon Q235 500X

Lokacin da ƙarfe ya yi zafi, idan dai akwai rarrabuwar phosphorus a cikin billet, ba shi yiwuwa a sami microstructure iri ɗaya.Haka kuma, saboda tsananin rarrabuwar sinadarin phosphorus, an samar da tsarin “fatalwa waya”, wanda babu makawa zai rage kayan aikin injina..

Rarraba phosphorus a cikin ƙarfe na carbon abu ne na kowa, amma digiri ya bambanta.Lokacin da phosphorus ya keɓanta sosai (tsarin "layin fatalwa" ya bayyana), zai kawo mummunan tasiri ga ƙarfe.Babu shakka, tsananin rarrabuwar kawuna na phosphorus shine laifin fashe kayan abu a lokacin aikin sanyi.Saboda nau'in hatsi daban-daban a cikin karfe suna da nau'in phosphorus daban-daban, kayan yana da ƙarfi da taurin daban-daban;a gefe guda, shi ne kuma Yi kayan da ke samar da damuwa na ciki, zai inganta kayan da za su iya yin kullun ciki.A cikin kayan da tsarin "fatalwa waya", shi ne daidai da rage taurin, ƙarfi, elongation bayan karaya da raguwa na yanki, musamman ma rage tasiri taurin, wanda zai kai ga sanyi brittleness na abu, don haka da phosphorus abun ciki. da tsarin kaddarorin karfe Suna da kusanci sosai.

Gano Metallographic A cikin "layin fatalwa" a tsakiyar filin kallo, akwai adadi mai yawa na sulfide elongated launin toka.Abubuwan da ba na ƙarfe ba a cikin ƙarfe na tsari galibi suna kasancewa a cikin nau'in oxides da sulfides.Dangane da GB/T10561-2005 "Tsarin Tsarin Tsarin Tsarin Karatun Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwaƙwalwa na Ƙarfe ", nau'in nau'in B yana da lalacewa a wannan lokacin matakin kayan ya kai 2.5 da sama.Kamar yadda muka sani, abubuwan da ba na ƙarfe ba sune yuwuwar tushen fasa.Kasancewarsu za ta lalata ci gaba da ƙaƙƙarfan tsarin ƙananan ƙarfe, kuma yana rage ƙarfin tsaka-tsakin ƙarfe sosai.An yi la'akari da wannan cewa kasancewar sulfides a cikin "layin fatalwa" na tsarin ciki na karfe shine mafi kusantar wuri don fashewa.Saboda haka, sanyi ƙirƙira fasa da zafi magani quenching fasa a cikin wani babban adadin fastener samar da wuraren da aka lalacewa ta hanyar babban adadin haske launin toka siriri sulfides.Bayyanar irin wannan mummunan saƙa yana lalata ci gaba da kaddarorin ƙarfe kuma yana ƙara haɗarin maganin zafi.Ba za a iya cire "zaren fatalwa" ta hanyar daidaitawa, da dai sauransu, kuma ya kamata a kula da abubuwan da ba su da kyau daga aikin narka ko kafin albarkatun kasa su shiga masana'anta.

Abubuwan da ba na ƙarfe ba sun kasu kashi alumina (nau'in A) silicate (nau'in C) da spherical oxide (nau'in D) bisa ga abun da ke ciki da nakasa.Kasancewarsu yana yanke ci gaba da ƙarfe, kuma ramuka ko tsagewa suna tasowa bayan bawo.Abu ne mai sauqi don samar da tushen tsagewar lokacin sanyi da kuma haifar da damuwa yayin jiyya na zafi, wanda ke haifar da fashewar fashewa.Don haka, abubuwan da ba na ƙarfe ba dole ne a sarrafa su sosai.Karfe na yanzu GB/T700-2006 "Carbon Structural Steel" da GB/T699-2016 "Ma'auni mai inganci Carbon Tsarin Karfe" ba sa bayyana buƙatu don abubuwan da ba na ƙarfe ba..Don mahimman sassa, ƙananan layukan A, B, da C gabaɗaya ba su wuce 1.5 ba, kuma D da Ds m da lauyoyi masu kyau ba su wuce 2 ba.


Lokacin aikawa: Oktoba-21-2021