The presen t study gives a review on basic types of crystallographic textures deve loping during hot rolling ot polycrvstatline stee ls. The re- sults are grouped ...
Mat eria ls tec hnolog y
Dedicated to Professor Dr.-IIlX. Oskar Paw elski on th e occasion of his 70th birthday
Overview on Basic Types of Hot Rolling Textures of Steels Dierk Raabe Max-Planck-Institut lur Eisenl orsch ung, Dusseldorf,' Germany. The presen t study gives a review on basic types of crystallographic te xture s deve loping during hot rolling ot polycrvstatline stee ls. The resu lts are grouped into three fundamental clas ses of textures The first group comprise s pure Fe, some weak ly bonded 62 and 0 0 3 structured intermetaues. as well as closely re lated a lloys suc h as temnc 101'1 ca rbon and microalloyed interstitia l free stee ls. The se cond group Includes highly a lloyed co rrosion-resista nt territic stainless and Fe-St transformer steels, Typica l exa mple s a re ste els with eoc ctt o 1'11.%171'11.% Cr. with abo ut 3 wt,% St. as well a s body ce ntered cubic trans ition me tals such as Ta. Mo. and Nb which do not undergo any phase transformation during hot rolling, The third group comprises sta ble and Instable auste nitic stainless stee ls for instance on the basis of la rger a mounts 01 Cr and Ni or on Mn a s we ll as duplex stee ls. Most l1 2 structured intermeta llic alloys can a lso be as s igned 10uus group. The su ggest ed classification sch e me is discuss ed in terms of differe nt proces s ing pa ra mete rs, the rmodyna mics, microstructure . and crystallographic as pects. Oberblick ucer d ie wesenllichen Type n von Warm walzte xturen vo n s ta me n. Diese Studie gibt eine n Ube rblic k ube r die wes emuche n Type n krista llograpisc he r Texturen von warmpewatzte n polykrista lline n Stahlen. Die Ergeb nisse lassen sich in d re i tundarnent ale Texturklassen enteuen . Die e rste Gruppe urntas st rernes Fe, e inige sch wach gebunde ne 62 und 00 3 struktunerte mtermetamscne Phasen und e ng verwandte Legierunge n sowe temtisc he niedriggekohlte ur c mikrolegierte IF-Stahle, Die zwe ite Gruppe umrass t hochtepe rte kcrrcsionstestanciae iernnscne Edelstahle unc Fe-Si-Transforrnatc rstahle. Typische Beispiele sind Stahle mit erwa 10 bis 17 Gew.% Cr. mil etea 3 Gew.% S i s owie kubtsch-raomzentnerte Uberpenqsreetaue wle t a Mo und Nb, die keine Pbasen umwanciunq war osno der w armumtormung ourctnauren. Die dritte Gruppe urntasst sta bile uno lnstabue austemusche Edelsta hle zum Beispie l auf c er Basis von gro l3e re n leglerungsante ilen an Cr und Ni oder Mnsowe Duplex-Edelstahle. Zahlreiche L12 strukturierte mtermetaihsche Leqienmqen kennan ceser Oruppe ebe nlalls zugeordnet werc en Das vcrqescblaqe ne Klassifizierungsschema wird im Hinblick a uf ur ue rscmecucre Hers tellbed ingungen, Thermodynamik. Mikrostruktueen und krtslalloqraphische Aspekte crskunert.
Intrud uc t ion T he a pp lica tion of q ua ntitat ive texture ana lys is in te rm s o f the ori entation d ist ri bution func tion (O DH [ 1.2 J to ste el s and related a llo y s. T he use o f the OOF pro v ides te xt ure data for hOI rolled ste els w h ich a re suffic ie nt ly de tailed 10 rev eal r bar acu-ris tic differ en ce s be t wee n the va rio us groups of steels. T he main parameter-s leadi ng to d iffe re nt c lasses of hot hand steel te xture s can he arran ged in fo ur g ro ups, ta b le I . The first g ro up includ es the proce ssing pa ramete rs. suc h as c as ting (e .g. contin uous cast ing , th in str ip ca sti ng }, slab treatment (e .g . slab a nneali ng temperatu re , soa k ing t im e ), pr e-rol ling . and hut ro ll ing sc he dule te .g . fc rr iric ro ll ing , austen itic ro lling, red uction sc he me. mac roscopi c th rou ghthicknes s strai n rate profiles ). The seco nd grou p incl ud e s th er mody na m ic quantitie s suc h as the amount and kind of a llo y ing clements . impuritie s. tr ansfo rmation be haviour. sto red deformation ene rgy , an d the Slacking fuult e ne rgy o f the au stenitic ph as e. T he th ird gro up com prise- mi crostructu ra l pa ra meters s uch as the g ra in size anti shape , recrystal lizat io n tem perature and lim e , shea r han d s, and precipirations. The fourth g ro up c on tains cryst a llog ra ph ic aspects such as the acti ve sli p sys te ms in th e d ifferent phase s, ins te el research 74 (20 03) NO. 5
hc ritcd textures. a nd ori ent at io n relationshi ps duri ng tr an sformation rc.g. Buin or Nistuyama -wassermanm . lh c tex ture re sults presented in th is overview fo r a nu mhe r of d iffe ren t types of hot rolled steel s su ggesls to e xta blish three basic class es o f hot band ste etrextures . The first g roup ( in th e follow ing termed group (A) comprises pu re Fe , some we akl y bonded B2 an d DOl structured int er me tallics . a s w e ll as the closely rel ate d fc rrit ic low c arbon and mtc rstuia l fr ee (I F) steel s , T he second gro up ( in th e fol lo w ing termed g rou p {B l includes high ly al lo ye d fcrritic stainless and Si-steels. particularl y steel s w ith about 10 \\'\.';( - 17 w\. '!r, Cr or wit h ab out .1 w t.{7, Si as well as BCe tr an sit ion metals such a s Ta , Mo. C r. and Nb w h ich do not unde rgo a phase t ra ns for m at io n durin g hot ro lling . The th ird gro up (i n the following terme d g ro up (C ) comprise s stable and invtahle auste n itic sta in less ste el s for insta nc e on the basi-, o f la rge r amounts o f Cr and Ni or on Mn as well as d u plex steels. Mo st Ll ~ structured inturmctalfic alloy s ca n als o be a ~ s l gned 10 rhi-, g ro up. Earlier re vie w s on the mai n e leme nt s of th e c ry stall o g ra ph ic tex t ures of hot rolled stee ls we re p ublishe d by Wassermann an d Grcwcn [3 1. Holsc he r ct a1.1451, Ray an d Jo nas Ih J, an d Raabe e r a I.1 7 - 13 1.
Experim ental As ex a m p les for the different gro ups of hot roll ed steel s th e c ur re nt article revi ew s data for IF de ep dr aw ing steels,
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