Effect of B/N ratio on plastic anisotropy behaviour in low carbon aluminium killed steel

摘要

It is well known that dissolved nitrogen in ferritenseriously impairs the formability of hot rolled unalloyednsteel.1–3 Boron being a strong nitride former, combinesnaggressively with dissolved nitrogen in steel, and therebynimproves the forming properties. Further, atomic rationof boron to nitrogen (B/N) plays an important role inninfluencing the microstructure and properties3,4 of lowncarbon steel. Whenever excess boron is present innsolution in austenite, it segregates to the c grainnboundary, thus inhibiting the transformation of austenitento ferrite, and resulting in increase in hardenabilitynof steel.5 Although plenty of works6,7 have been carriednout on the effect of boron on properties of hot rollednsteels, limited literature is available on its effect in coldnrolled formable grades particularly when carbon is in thenrange 0?03–0?06 wt-%. The present paper discusses theneffect of B/N atomic ratio on the forming properties inngeneral and plastic anisotropy ratio rm in particular, innlow carbon aluminium killed batch annealed steel.