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182 ^1198 tr -Ef=E 64 ag ^I+6Izl g=4. I+qq Mntg FEr}(aucor steer)olel 6lt, €e-|ol E =49 E^] Mn 1-20/o, C 0.2-ta/o H+lolr+. a+, .tr+, r*ul Fq 9eI +a+gg ^I*q q, B+e+ 820-850t'C I "l ^l +B 6Ir, 500--600c g.= 150-200"c oil ^ -l tlB = "J + +. II+Eg d}EgE?(hardfield steel)olzl-z 6}q, gaEl4"lq =4E "Jzl7}ol4. Mn L1-t4o/o, C 0.9-t.3o/ool Ir-E Agzy +oI^J 4olE* z|-tr-tr 2loJtrI. ol ,Jg t g"il^] Tcol czl o_s 1000-1100cqJ^J ++ B+a6L= +?lB(water toughing) o -tr "JCg +q+4. +E= ilil l.il BI"J Fq '^olq,.]l"IECg 9rI;. d4z} 7C"l S,E zIEQI 4'J6I4.6IEgErlg +"Ji'l46IE g.EIrJole =4ol 9gE €+ol 7l.b6l4l+. trB e-4elE (a)E eo/oMng +++ 14 oE 1,000cq1^J tB+ au|-rllzlolq z 49 +4'J 4o14, Ll-Lro/oMng4 gaEil4olqg+eJ ts46IH qt S,ol +d + ,Je euleJl,+olETl czl-a, 4l+€ ts49e d^} +d aElHlzlol eg HEI++. (b) = r3.8o/o Mn$ +++ rJel ulQlzlol e CCg 4e},{1 ilgq, 1,000Cq1^.1 +ts6} 1s1 1xs00) (b) (x2,000) (c) (x2,000) ral 9_49 MnB 4al (d) (x1,000)