Effect of Aging Temperature on the Mechanical Properties of Cold Hardening Microalloyed Bainitic Steel
YANG Jin-feng1,2,HUI Wei-jun1,2,YU Tong-ren3,SUN Wei3,LONG jin-ming1
1. Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China 2. National Engineering Research Center of Advanced Steel Technology, Central Iron and Steel Research Institute, Beijing 100081, China 3. Technical Center, Maanshan Iron and Steel Co., Ltd., Ma’anshan 243002, Anhui, China
Abstract:The effect of aging temperature on the mechanical properties of low carbon Mn-B-Ti type cold hardening microalloyed bainitic steel was investigated. Experimental results show that strength increases at first and reaches a peak at about 250℃, and then decreases with the increase of aging temperature. The decrease of strength is more significant when aging temperature is higher than 400℃. Both ductility and strength ratio increase with increasing aging temperature, while the latter is more significant. The charging of hydrogen significantly impairs the delayed fracture property of the steel subject to 30% cold drawing. Hydrogen content decreases with increasing aging temperature and thus both notch tensile strength and delayed fracture strength ratio increase. The increase of notch tensile strength and delayed fracture strength ratio is more noticeable when aging temperature is higher than 200℃. Therefore, with the precondition of required low permanent deformation, strength and ductility, aging temperature should be chosen carefully to maintain a relatively high application property of delayed fracture resistance.
杨金峰,,惠卫军,,于同仁,孙维,龙晋明. 时效温度对贝氏体型冷作强化非调质钢力学性能的影响[J]. 钢铁, 2011, 46(10): 84-87.
YANG Jin-feng1,2,HUI Wei-jun1,2,YU Tong-ren3,SUN Wei3,LONG jin-ming1. Effect of Aging Temperature on the Mechanical Properties of Cold Hardening Microalloyed Bainitic Steel. Iron and Steel, 2011, 46(10): 84-87.