Abstract
The present investigation was carried out to ascertain the effect of nitrogen on the elongation at yield-point and the serrated deformation in steel.
Tensile tests were carried out with irons, low carbon steels and low manganese steels containing various amounts of nitrogen, at the temperatures from 0° to 320°.
All the specimens were air cooled from 950°, and then slowly cooled after tempered for 3 hours at 550°C.
From the present investigation authors concluded as follows:
(1) There is a clear correlation between the nitrogen in steel and the elongation at yield-point or the serrated-deformation.
(2) In pure iron the serrated-deformation increased severely with the increase of nitrogen up to 0.007 percent,over which the slow increasing may be seen.
(3) With the increase of the rate of deformation,the degree of serrated-deformation apparently decreased and the elongation at yield-piont increased a little.
(4) The range of severe increasing of the serrated-deformation and the elongation at yield-point are reduced by carbon.
(5) By the addition of denitrogenizer on low manganese steel the serrated-deformation and the elongation at yield-point diminished or almost disappeared.
