Development of a Computer-Controlled Hot-Deformation Apparatus at NIST (National Institute of Standards and Technology)

摘要

The report describes a computer-controlled hot-deformation apparatus suitable for thermomechanical-processing (TMP) simulation of forging and steel plates. The apparatus was designed and built at the National Institute of Standards and Technology, and has the following main features: a servohydraulic load frame with a 250 kN capacity in tension or compression; a variable-actuator traveling speed up to 55 mm/s; a multiple-strike capability with controllable displacements and strain rates; a maximum heating rate of 150 c/s with a 10 kW induction heater (for a cylindrical steel specimen 9 mm in diameter and 18 mm in height); a maximum cooling rate of 25 c/s with helium-gas cooling; and vacuum to 1.33 x 10 sup (-3) Pa (1 x 10 sup (-5) Torr) within 25 min. Source codes of the computer programs that perform system control, data acquisition, and data analysis are included in the report. The apparatus has been used to perform the direct-quenching simulation of the ASTM A710 plate steel, and forging simulation of the directly cooled microalloyed AISI 1522 and 1141 steels. Results of the studies are presented.