Modified ausforming is one of effective methods of toughening the steel. In this paper, we made simulated experiments to get basic knowledge of modified ausforming of spring steel, with the simulator hot working, and investigated effect by modified ausforming to hardness and structure. And we investigated how it influenced effect by modified ausforming, by changing conditions of modified ausforming such as working temperature.
This main conclusions are summarized as follows:
(1) Quenched hardness rises and martensite is refined by modified ausforming.
(2) In the case of modified ausforming at 650°C in SUP9A, the diffusion transformation is accelerated and hardning is imperfect, so the hardness remarkably drops. And in the case of the process at more than 800°C, the effects of the process decreace by recrystallization.
(3) With the prolongment of the air cooling time before quenching, the effect of modified ausforming decrease by recovery and recrystallization.
(4) Tempered hardness rises by modified ausforming.
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