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Investigation Of Nigerian Steels For Cryogenic Application

Inegbenebor, A.O. (2002) Investigation Of Nigerian Steels For Cryogenic Application. NSE TECHNICAL TRANSACTIONS, 37 (1).

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Abstract

Nigeria produces )Steels and has just entered the league qf Nat!Pfl$ whic!l export ( .. .. . . ' . ~~i4.f?l .9as in t,he t?rm R! li9ui,ti~.d q~tur~l Q'+~ (~f\1~). L~ h l r;l' • ' ', • In order to use Nig~rian ~teets. for cryo~epic temperature applic;ations, th)s \o'Jork i.s. undert~ken to examin~ the possibility of ~ : . ' . . ' \ . ' ' . . further developing the steel(?) vyhich ~now promis~ from cryog~nic temperature tests. Samples of I'Jig~pan popular steel~ , j J ' !' ••; < >' I I ' NST44-2, NST-60-2 and NST 60 Mn were mac,hin~d i~lp ~tan~Cird qh~rpy imp~ct ~esting ··• · - . ... . . ' ~w~pim~m . a.~ ~pe~Ifi~'~ by ASTM. These ' samples were neat treated by soaking for 1 l i~: .. -1•{ t '~! ~ ,t.t: o: f ,J~i'\ ! ,{. :·. ~ : ' - hour at 930.0C and cooled in the air. • ; . ; : . . ' : ·. ~ ' i . Impacts tests were conducted on these specimens, of ~~ rolled and normalis~d conditions at room and cryogenic t~mper~wres of 0?,~ (273K), -59C ~?(?~~). - l..i o,,.,\;1 ,,, · 1 · • · · • · • · · ) 1 OoC (263K) and -15oC (258K). ·i' r ::.i j ; ; i ' : ~ ~ .: ::- '! • 1 j , i ;. 'i ~ , ;. ! ) ~ ! ' : The results show that the steel NST 44-2 · is prom!sing for ~ryogenic ~pplicatiqns. The ductile fracture in NST 44-2 can be attributed -~-- __ ... _.,._~...,. . ... tq t,~fi norm~llslrg ~ffect, where more ferrite was transformed ~han pE:}arlite from (a + y) reQion of the heat treatment, which resulted jn g_r?in _retirem~nt and decrease in ductileqrit. t!e transition tef'T!peratures. The ductility of ,;. ··' ., ':· • - I ' ~ ·-- ' . . . th~ ~~mple is due to low carbon content of the. material. I~TR ODUCTION The Nigerian steel company, has been producing different grades of steels for · con~truction and manufacturing industries for engineering component parts. Nigeria as natural gas producing nation ~ith abund~nt reserves, needs to look inwards to use her steels to manufacture the essential component parts for the gas industry. In order to use Nigerian steel for this · purpose, it must be noted that the engineering properties of most structural steel? ch~n9e ~ubs~antiaUy a~ temperature is q~c,re~~~·o .to V~JY ·lpw y~!u~. that Is In cryogen.!c applic(l~ions. Common property change~ include dhnens.iqn~l contraction, increas~s in yi~'d ~nd tensjl~ $trengths, ano . ' \ high energy absorbed -aycompanied by decrease in fractur~ tough~~~s. wit~ · the latt

Item Type: Article
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TJ Mechanical engineering and machinery
Divisions: Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User: Mrs Hannah Akinwumi
Date Deposited: 30 Mar 2015 12:12
Last Modified: 30 Mar 2015 12:12
URI: http://eprints.covenantuniversity.edu.ng/id/eprint/4415

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