Effect of Austenitizing Time on Microstructure and Properties of Carbide Free Bainite Steel
Author of the article:CHENG Yan;CHENG Juqiang;LI Zhenfei
Author's Workplace：School of Materials Science and Chemical Engineering,Xi'an Technological University,Xi'an 710021,China
Key Words：carbide free bainite soaking time mechanical property
Abstract：
The effect of austenitizing heating time at 920℃on the microstructure and mechanical properties of20 SiMn2 Mo carbide-free bainite was studied.The results show that 920℃heat treated by different heat preservation time,coefficient of tensile strength in the time of heat preservation is less than 2.5 mm/min when little change,in the heat preservation time there was a peak coefficient of 2.0 mm/min.When the insulation time coefficient exceeds 2.5 min/mm,the strength decreases,with the increase of holding time,the impact value increased first and then decreased and then increased,the peak value appeared when the insulation time coefficient was 1.5 min/mm and 4.0 min/mm.The microstructure of the air cooling experimental materials with different holding time was bainitic ferrite and residual austenite,and the microstructure was carbid-free bainitic.In terms of energy saving,oxidation prevention and decarbonization,the experimental material had good strength and toughness when the austenization heating and holding time coefficient was 1.5 min/mm.
