Ductility in Chromium

MUCH recent work has been carried out on the preparation and properties of pure chromium with the aim of establishing chromium base alloys as engineering materials. The obstacle to this, the room-temperature brittleness, has naturally attracted great attention. It has been suggested that the brittleness of chromium is promoted by nitrogen content above 20 p.p.m., by rough surface condition and by recrystallization. It had been found previously that the greatest lowering of the ductile/brittle transition temperature in chromium is obtained in polished pieces which have been worked below the recrystallization temperature. Complete recrystallization in rolled chromium raises the transition temperature so that there is usually no bend ductility at room temperature, although pieces in this condition showing ductility have been produced¹.