Effect of Cold Working and Annealing Condition on Scale Formation of AISI 4140 Steel

Abstract

The objective of this research was to investigate cold work of alloy steel which was affected on scale in annealing process. Material used in the experiment was alloy steel, AISI 4140, that widely used in automotive industry and it have been annealing after cold forming operation. The experiment was conducted on four level of percentage of cold work, 0% - 30%. The annealing temperature was set up at three levels between 845– 900°C and three type of controlled atmosphere in annealing consist of normal atmosphere and reduction atmosphere with two inert gas, nitrogen and argon. The result was indicated that percentage of cold work affected to formation of scale, high percentage of cold work, more percent weight of scale. Furthermore, the controlled atmosphere in annealing with nitrogen can be producing less scale surface than reduction with argon and normal condition, respectively. Moreover, the scale was a few affected by temperature of heat treatment in annealing. High temperature could be produced more scale surface than low temperature in all percentage of cold work