Abstract: A Cam plastometer is adapted. The experimental study of the resistance to plastic deformation of four types of steel (200Cr 40Cr, T8A, Tl2A) has been made during the compression of the specimen under high temperature and high speed.
The experimental range was as follows:temperature 850-1150℃;rate 5-80S^-1; and extent of reduction e_max=lnho/h=ln2.
This paper mainly analyes the influence of the temperature, rate and the extant of the reduction on the resistance to deformation of these four type's of steel, and results of 20Cr and T8A are in compar-sion with 40Cr and Tl2A. In this paper, there are a formula for calculating resistance to deformation and some graphic charts which may be useful for engineers and technicians. The experimatal result of T8A is compared to the other study of some foreign scholars.