karfe
Alloy
Bayanai
Ƙaramin ɓangare na	ferroalloy
Color	grey
Time of discovery or invention	1865
Fabrication method	steelmaking
Recycling code	40

Karfe wani abu ne da aka yi shi da ƙarfe tare da karin carbon don inganta karfinsa da juriyar karaya idan aka kwatanta da sauran nau'ikan karfe. Wasu abubuwa da yawa na iya kasancewa ko kara su. Bakin karfe wadanda suke corrosion-da oxidation-resistant yawanci suna bukatar karin 11% chromium. Saboda tsananin karfinsa da karancin farashi, ana amfani da karfe a cikin gine-gine, ababen more rayuwa, kayan aikin, jiragen ruwa, jiragen kasa, motoci, inji, na'urorin lantarki, makamai, da rokoki. Iron shine tushen karfe na karfe. Dangane da zafin jiki, zai iya daukar nau'i biyu na crystalline (siffofin allotropic): mai siffar jiki da mai siffar fuska. Hadin kai na allotropes na bakin karfe tare da abubuwan hadin gwiwa, da farko carbon, yana ba da karfe da jefa bakin karfe kewayon su na musamman.

A cikin tsantsar bakin karfe, tsarin crystal din yana da dan karamin juriya ga kwayoyin karfe suna zamewa da juna, don haka tsantsar bakin karfe ba shi da karfi sosai, ko taushi da saukin samu. A cikin karfe, kananan adadin carbon, wasu abubuwa, da abubuwan da aka hada a cikin karfe suna aiki azaman masu taurare wadanda ke hana motsin barna. Carbon a cikin al'amuran karfe na yau da kullun na iya ba da gudummawa har zuwa 2.14% na nauyinsa. Bambance-bambancen adadin carbon da sauran abubuwa masu haɗawa da yawa, da kuma sarrafa sinadarai da kayan aikinsu na zahiri a cikin karfe na karshe (ko dai a matsayin abubuwan solute, ko a matsayin matakan hadaka), yana hana motsi na barna wadanda ke yin tsattsauran karfe na karfe, don haka sarrafawa da hadaka halayensa. Wadannan halaye sun hada da hardess, quenching behaviour, buƙatar annealing, tempering behaviour, yield strength , da tensile strength na sakamakon karfe. Karfafa karfin karfe idan aka kwatanta da ƙarfe mai tsabta yana yiwuwa ne kawai ta hanyar rage karancin karfe.

An samar da karfe a cikin tanderun furanni na dubban shekaru, amma babban sikelinsa, amfani da masana'antu ya fara ne kawai bayan an kirkiri ingantattun hanyoyin samar da kayayyaki a cikin karni na 17, tare da gabatar da tanderun fashewa da samar da karfe mai kyalli. Wannan ya biyo bayan tanderun bude ido sannan kuma tsarin Bessemer a Ingila a tsakiyar karni na 19. Tare da kirkira tsarin Bessemer, sabon zamani na karfe da aka samar da yawa ya fara. Karfe mai laushi ya maye gurbin karfe da aka yi. Jihohin Jamus sun ga babban karfin karfe a kan Turai a karni na 19.

Karin gyare-gyare a cikin tsari, kamar asali na oxygen steelmaking (BOS), sun maye gurbin hanyoyin da suka gabata ta hanyar kara rage farashin samarwa da hadaka ingancin samfurin karshe. A yau, karfe yana daya daga cikin kayan da aka fi kerawa a duniya, yana da fiye da biliyan 1.6 tons da ake samarwa a kowace shekara. Karfe na zamani gabadaya ana gano shi ta nau'o'i daban-daban wadanda kungiyoyi daban-daban suka ayyana. Masana'antar karafa ta zamani tana daya daga cikin manyan masana'antun masana'antu a duniya, amma tana daya daga cikin masana'antu masu karfi da makamashi da gurbataccen iska, wanda ke ba da gudummawar kashi 8% na hayakin duniya. Koyaya, karfe shima ana iya sake amfani dashi: yana ɗaya daga cikin kayan da aka fi sake yin fa'ida a duniya, tare da kimar sake yin amfani da su sama da 60% a duniya.

1. R., Allen. "(1979). International Competition in Iron and Steel, 1850-1913". JSTOR. Cambridge university. JSTOR 2120336
2. "Decarbonization in steel | McKinsey". www.mckinsey.com
3. Hartman, Roy A. (2009). "Recycling". Encarta. Archived from the original on 2008-04-14.