Post ƙirƙira zafi jiyya na bakin karfe forgings, kuma aka sani da farko zafi magani ko shiri zafi magani, yawanci za'ayi nan da nan bayan ƙirƙira tsari da aka kammala, kuma akwai da dama siffofin kamar normalizing, tempering, annealing, spheroidizing, m bayani. da sauransu. A yau za mu koyi game da da yawa daga cikinsu.

Daidaitawa: Babban manufar ita ce tace girman hatsi. Heat da ƙirƙira sama da lokaci canji zafin jiki don samar da guda austenite tsarin, daidaita shi bayan wani lokaci na uniform zafin jiki, sa'an nan cire shi daga cikin tanderun for iska sanyaya. Adadin dumama yayin daidaitawa yakamata ya kasance a hankali ƙasa da 700℃don rage bambancin zafin jiki na ciki da na waje da damuwa nan take a cikin ƙirƙira. Zai fi kyau ƙara matakin isothermal tsakanin 650℃kuma 700℃; A yanayin zafi sama da 700℃, musamman a sama da Ac1 (matsayin canji na lokaci), yawan dumama na manyan ƙirƙira ya kamata a ƙara don cimma sakamako mafi kyau na gyaran hatsi. Matsakaicin zafin jiki don daidaitawa yawanci shine tsakanin 760℃kuma 950℃, dangane da yanayin canjin lokaci tare da abubuwan da ke cikin sassa daban-daban. Yawancin lokaci, ƙananan carbon da abun ciki na gami, mafi girman yanayin yanayin daidaitawa, kuma akasin haka. Wasu makin karfe na musamman na iya kaiwa iyakar zafin jiki 1000℃zuwa 1150℃. Duk da haka, da tsarin canji na bakin karfe da kuma wadanda ba ferrous karafa ana samun ta m bayani magani.

Tempering: Babban manufar shine fadada hydrogen. Hakanan yana iya daidaita microstructure bayan sauyin lokaci, kawar da danniya na canjin tsarin da rage taurin, yin ƙirjin ƙarfe na ƙarfe mai sauƙin aiwatarwa ba tare da nakasawa ba. Akwai kewayon zafin jiki guda uku don zafin jiki, wato babban zafin jiki (500℃~660℃), matsakaicin zafin jiki (350℃~490℃), da ƙananan zafin jiki (150℃~250℃). Samar da gama gari na manyan jabu suna ɗaukar hanyar zafi mai zafi. Tempering gabaɗaya ana aiwatar da shi nan da nan bayan al'ada. Lokacin da ƙirƙira na yau da kullun yana sanyaya iska zuwa kusan 220℃~300℃, ana sake dumama shi, a yi zafi sosai, sannan a sanya shi a cikin tanderun, sannan a sanyaya shi zuwa ƙasa da 250.℃~350℃a saman injin da aka yi kafin a fitar da shi daga tanderun. Adadin sanyaya bayan zafin jiki yakamata ya kasance a hankali don hana samuwar farar tabo saboda tsananin damuwa nan take yayin aikin sanyaya, kuma don rage yawan damuwa a cikin ƙirƙira gwargwadon yiwuwa. Tsarin sanyaya yawanci ana kasu kashi biyu: sama da 400℃, Kamar yadda karfe ke cikin kewayon zafin jiki tare da filastik mai kyau da ƙarancin ɓarna, ƙimar sanyaya na iya zama ɗan sauri; Kasa da 400℃, Kamar yadda karfe ya shiga cikin kewayon zafin jiki tare da tsananin sanyi mai ƙarfi da raguwa, ya kamata a ɗauki matakan sanyaya a hankali don guje wa fashewa da rage damuwa nan take. Don karfe wanda yake kula da fararen spots da hydrogen embrittlement, wajibi ne don ƙayyade tsawo na lokacin zafi don fadada hydrogen bisa ga daidaitattun hydrogen da girman girman giciye na ƙirƙira, don yaduwa da zubar da hydrogen a cikin karfe. , kuma rage shi zuwa amintaccen kewayon lambobi.

Annealing: Zazzabi ya haɗa da duka kewayon daidaitawa da zafin rai (150℃~950℃), ta yin amfani da hanyar sanyaya tanderu, kama da zafi. Rushewa tare da zafin jiki mai zafi sama da wurin jujjuya lokaci (tsawon zafin jiki na daidaitawa) ana kiransa cikakken annealing. Annealing ba tare da canji lokaci ana kiransa rashin cikawa annealing. Babban manufar annealing shi ne don kawar da danniya da kuma daidaita microstructure, ciki har da high-zazzabi annealing bayan sanyi nakasawa da kuma low-zazzabi annealing bayan waldi, da dai sauransu Normalization + tempering hanya ce mafi ci gaba fiye da sauki annealing, kamar yadda ya ƙunshi isasshen lokaci canji. da sauye-sauyen tsari, da kuma tsarin fadada hydrogen na zafin jiki akai-akai.