Effects of Variations in Heat Treatment on the Mechanical Properties and Microstructure of ASTM A710 Grade A Class 3 Steel.

摘要

A final report assessing the effects of variations in heat treatment on the mechanical properties and microstructure of ASTM A710 grade A class 3 steel is given. The goal of this project was to evaluate the sensitivity of the mechanical properties of A710, an age hardening steel, to heat treatment variations that may occur in the production of thick plate. Tensile and impact tests were conducted on the material heat treated under the various conditions. Microstructure evaluations using optical and electron metallographic methods were conducted. Small angle neutron scattering examinations were also performed on selected specimens in order to evaluate the precipitate distribution. Results indicate that austenitization and aging time has little effect on the resultant mechanical properties. However, the mechanical properties were found to be sensitive to aging temperature. Impact results at 0 F indicate that aging at 900 F is detrimental in that the fracture surfaces of the broken impacts exhibited cleavage. Furthermore, the results suggest that welding or similar heating operations will not seriously degrade this material's properties.