The effects of Si and Mn contents on transformation temperature r3, transformed microstructure and mechanical properties of three kinds of low-carbon steels during continuouscooling were investigated. A r3 rises by 15-25°C when increasing Si content from 0.50% to 1.35%, and it drops by 30-50°C when increasing Mn content from 0.97% to 1.43%. The effect of Mn on A r3 is more significant than Si. Si stimulates the precipitation of the high-temperature equiaxed ferrite to suppress the bainite transformation, but Mn not only provides the grain refining of transformed microstructure but also stimulates the forming of bainite. The homogeneous and grain refining diphase ferrite/bainite steel (w(Si)=0.56, w(Mn)=1.43) can be obtained after deformed at 850°C and cooled at the rate 30°C/s, of which the tensile strength is up to 654 MPa.
Original language: Chinese
Field of Research
089999 Information and Computing Sciences not elsewhere classified 099999 Engineering not elsewhere classified 109999 Technology not elsewhere classified
Socio Economic Objective
970108 Expanding Knowledge in the Information and Computing Sciences