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The drawabilities of low carbonnilrogen-aluminulIl steeh were examined by means of Conical Cup T esting mel hod with no-nitrogen-aluminulll low carbon steels as riference. It w as found that a com/)osition comjlrising less than 0.03~0 carbon, less than 0.05% silicon , between 0. 2°0 and 0. 5° ° manganese, between a/JjJroximately 0.010° ° and 0.022° ° nitrogen to couj)le w ith ajJjJroximately 2.5 to 6" times as much aillminwn should give rise 10 imjJroved drawabilities. A s for Ihe manufacturing m.ethod, one that is consisted of hot rolling (fi nal/lass) in a range of ajljJrOximately 800° to 920"C (typically 850°C), annealing in a range of 700° to 850°C (tyjlically 800°C), and cooling in air or at a rate roughly one half as much (or, " coiling down low", in term s of modem mass /noduction practices) was seen 10 be /Jriferable. The imjnoved drawabilities of Ihe :\-AI steels were ascribed 10 Iwo factors : in the firsl, the formatioll of annealing lextwoe that is favo rable fo r drawability is encouraged by free nitrogen and free alum inum exisling in the to-be-cold-rolled matrix in approximale range of 0.011 to 0.017° ° and 0.01 to 0.06 ";0' res/)ectively; while in Ihe second, the du ctility of steel is enhanced by the minute aluminum nitride /Jrecipilate particles. The effects qf free nitrogen, free aluminum , retained aluminum nitride, and re/Jrecijlitated aluminum nitride on recrystallization were discussed. The deteriorative effect qf excess aluminum , on the other hand, was seell to be f airly great.

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