THE RELATION OF FORGEABILITY AND CAST STRUCTURES OF Timken 16-25-6

On the forgeability of the transformation-free alloy ingot-I

Abstract

There are many experiments on the forging of metals, but these are studied to know strain and stress at a impact working, or from the view point of strength of material. There are seldom from the view point of metallic material technology. For the present situation, the authors studied the forgeability of a less forgeable ingot from the view point of metallic material engineering.
The samples used in this experiment are 15×15mm, and of columnar structure, granular one and both mixed. Forging temperatures are 800°C, 900°C, 1100°C and 1300°C. In the case of columnar stucture sample and both mixed one, they compressed impactly the columnar axis parralel to the forging directon (longitudinal) and these stand at right angle each other (transversal), and various phenomena were examined.
Stress-strain curves are obtained by magnetic method. The results are as follows:
(1) Working resistance decreases in the case of the compressive working of granular structure, transversal one and longitudinal one, one by one.
(2) The difference of working resistance of (1) decreases with rising temperature.
(3) When the working velocity increased, a tendeny to increase this difference were observed.
(4) The relation between working degree log (h₀/h) and working energy is linear in the range of this experiment. Here, h₀: inital height of sample. h: height of sample after compression. (5) The crack forming possibility decreases with longitudinal columnar, granular one and tranversal one, according to the aforesaid order. (6) The forging temperature is a sensible factor of the crack forming possibility.