Ilimi yanki - zafi magani na ductile baƙin ƙarfe, simintin gyaran kafa dole fahimtar shi!

Akwai hanyoyin magance zafi da yawa da aka saba amfani da su don baƙin ƙarfe ductile.

A cikin tsarin baƙin ƙarfe ductile, graphite yana da siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar . Ayyukan baƙin ƙarfe ductile ya dogara ne akan tsarin matrix, kuma tasirin graphite shine na biyu. Inganta tsarin matrix na ductile baƙin ƙarfe ta hanyoyi daban-daban na zafi na iya inganta kayan aikin injiniya zuwa digiri daban-daban. Saboda tasirin sinadarai, ƙimar sanyaya, wakili na spheroidizing da sauran dalilai, tsarin gauraye na ferrite + pearlite + cementite + graphite sau da yawa yana bayyana a cikin tsarin simintin simintin, musamman a bangon bakin ciki na simintin. Manufar maganin zafi shine don samun tsarin da ake buƙata kuma don haka inganta kayan aikin injiniya.

Hanyoyin maganin zafi da aka fi amfani da su don baƙin ƙarfe na ductile sune kamar haka.

(1) Low-zazzabi graphitization annealing dumama zafin jiki 720 ~ 760 ℃. Ana sanyaya a cikin tanderu zuwa ƙasa da 500 ℃ sannan a sanyaya iska. Rushe siminti na eutectoid don samun baƙin ƙarfe ductile tare da matrix ferrite don inganta taurin.

(2) High-zazzabi graphitization annealing a 880 ~ 930 ℃, sa'an nan kuma canjawa wuri zuwa 720 ~ 760 ℃ don zafi adana, sa'an nan sanyaya tare da tanderun zuwa kasa 500 ℃ da iska sanyaya daga cikin tanderun. Kawar da farin tsarin da samun ductile baƙin ƙarfe tare da ferrite matrix, wanda inganta plasticity, rage taurin da kuma ƙara tauri.

(3) Cikakken haɓakawa da daidaitawa a 880 ~ 930 ℃, hanyar sanyaya: sanyaya hazo, sanyaya iska ko sanyaya iska. Domin rage danniya, ƙara tempering tsari: 500 ~ 600 ℃ don samun pearlite + karamin adadin ferrite + siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar, wanda ƙara ƙarfin, taurin da sa juriya.

(4) Incomplete austenitization, normalizing da dumama a 820 ~ 860 ℃, sanyaya Hanyar: hazo sanyaya, iska sanyaya ko iska sanyaya. Domin rage danniya, ƙara tempering tsari: 500 ~ 600 ℃ don samun pearlite + wani karamin adadin tarwatsa baƙin ƙarfe Tsarin jiki ya sami mafi kyawun kayan aikin injiniya.

(5) Quenching da tempering magani: dumama a 840 ~ 880 ° C, sanyaya Hanyar: man fetur ko ruwa sanyaya, tempering zafin jiki bayan quenching: 550 ~ 600 ° C, don samun tempered sorbite tsarin da inganta m inji Properties.

(6) Isothermal quenching: Dumama a 840 ~ 880 ℃ da quenching a cikin wani gishiri wanka a 250 ~ 350 ℃ don samun m inji Properties, musamman don inganta ƙarfi, tauri da kuma sa juriya.

Yayin maganin zafi da dumama, yawan zafin jiki na simintin shiga tanderun bai wuce 350°C ba. Gudun dumama ya dogara da girman da kuma rikitarwa na simintin, kuma an zaɓa tsakanin 30 ~ 120 ° C / h. Zazzabi na shiga tanderun don manyan sassa masu rikitarwa ya kamata ya zama ƙasa kuma ƙimar dumama ya kamata ya kasance a hankali. Zazzabi mai zafi ya dogara da tsarin matrix da tsarin sinadaran. Lokacin riƙewa ya dogara da kaurin bangon simintin.

Bugu da kari, ductile iron simintin gyare-gyaren kuma za a iya kashe saman ta amfani da babban mita, matsakaicin mita, harshen wuta da sauran hanyoyin samun high taurin, sa juriya da gajiya juriya. Hakanan ana iya bi da shi tare da nitriding mai laushi don inganta juriyar lalacewa na simintin gyaran kafa.

1.Quenching da tempering jiyya na ductile baƙin ƙarfe

Simintin gyare-gyare na buƙatu na buƙatar tauri mafi girma azaman bearings, kuma sassan simintin ƙarfe galibi ana kashe su kuma ana jin zafi a ƙananan zafin jiki. Tsarin shine: dumama simintin zuwa zafin jiki na 860-900C, sanya shi don ba da damar duk matrix na asali su daidaita, sannan a sanyaya shi a cikin mai ko narkakken gishiri don cimma ruwa, sannan a dumama da kiyaye shi a 250-350. °C don zafin jiki, kuma ainihin matrix ɗin an canza shi zuwa Wuta martensite kuma an kiyaye tsarin austenite, ainihin siffar graphite na ainihi ya kasance baya canzawa. Simintin gyaran gyare-gyaren da aka yi suna da taurin gaske da wasu tauri, suna riƙe da kayan shafa mai na graphite, kuma sun inganta juriya.

Simintin gyare-gyaren ƙarfe, azaman sassa na shaft, kamar crankshafts da sandunan haɗin injunan diesel, suna buƙatar ingantattun kaddarorin injina tare da babban ƙarfi da tauri mai kyau. Dole ne a kashe sassan simintin gyare-gyare da kuma fushi. Tsarin shine: ƙarfen simintin yana dumama zuwa zafin jiki na 860-900 ° C kuma a sanya shi don tabbatar da matrix, sannan a sanyaya shi a cikin mai ko narkakken gishiri don cimma ruwa, sannan a sanya shi a zazzabi mai zafi na 500-600 ° C zuwa sami tsari mai zafin rai. (Gabaɗaya har yanzu akwai ƙaramin adadin ferrite mai tsafta), kuma sifar zanen zane na asali ya kasance baya canzawa. Bayan jiyya, ƙarfin da ƙarfi sun dace da kyau kuma sun dace da yanayin aiki na sassan shaft.

2. Annealing na ductile baƙin ƙarfe don inganta taurin

Yayin aiwatar da aikin simintin ƙarfe na baƙin ƙarfe, baƙin ƙarfe na simintin launin toka na yau da kullun yana da babban yanayin fari da babban damuwa na ciki. Yana da wahala a sami tsantsar ferrite ko pearlite matrix don sassan simintin ƙarfe. Domin inganta ductility ko taurin sassa na simintin ƙarfe, simintin ƙarfe yakan kasance sau da yawa Ana mai da sassan zuwa 900-950 ° C kuma a ajiye su dumi don isashen lokaci don yin zafi mai zafi, sa'an nan kuma a sanyaya zuwa 600 ° C kuma a sanyaya. na tanderun. A lokacin aiwatarwa, siminti a cikin matrix yana raguwa zuwa graphite, kuma graphite yana haɓakawa daga austenite. Wadannan graphites suna taruwa a kusa da ainihin zane mai siffar zobe, kuma matrix ɗin gaba ɗaya ya juye zuwa ferrite.

Idan tsarin simintin simintin ya ƙunshi matrix (ferrite + pearlite) da graphite mai siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar siffar ƙwanƙƙwalwa da ferrite. Don wannan dalili, ɓangaren ƙarfe na simintin dole ne a sake yin zafi. Bayan an ware shi sama da ƙasa da eutectoid zafin jiki na 700-760 ℃, tanderun da aka sanyaya zuwa 600 ℃ sa'an nan sanyaya daga cikin tanderun.

3. Normalizing don inganta ƙarfin ductile baƙin ƙarfe

Manufar daidaita ductile baƙin ƙarfe shine don canza tsarin matrix zuwa kyakkyawan tsarin pearlite. Tsarin shine a sake dumama simintin ƙarfe na ductile tare da matrix na ferrite da pearlite zuwa zafin jiki na 850-900°C. An canza ainihin ferrite da pearlite zuwa austenite, kuma an narkar da wasu graphite mai siffar zobe a cikin austenite. Bayan adana zafi, austenite mai sanyaya iska ya canza zuwa pearlite mai kyau, don haka ƙarfin simintin ductile yana ƙaruwa.


Lokacin aikawa: Mayu-08-2024