A method for warmth treatment of a steel material and then cold-drawn the form of a material which can be manufactured

摘要

Steel to be 'cold-worked' (at a temp. 500 degrees C) is rapidly cooled to a temp. 850 degrees C after the last hot-working operation, and then heated in a reducing atmosphere to reduce the seale formed on its surface to ferite, which is an excellent recipient of a lubricant used for cold-working. The method is esp. suitable for hammering bearingballs.