摘要
针对马氏体时效钢18Ni(250)在动态拉伸和不同速度泰勒杆冲击下呈现剪切断裂破坏的特征,为了理解其剪切及Ⅱ型断裂韧性在复合型断裂中所起到的作用,借助Hopkinson拉杆装置,对18Ni(250)进行了高加载率下的复合受力试验。并根据该材料在不同加载率下剪切断裂模式的特征,重点对该材料进行了不同加载率下的Ⅱ型动态断裂韧性试验研究。结果表明:随着加载率的提高,18Ni(250)钢的起裂时间逐渐减小,但其Ⅱ型动态断裂韧性值不断增大;通过SEM微观分析发现,在不同加载率下18Ni(250)钢Ⅱ型动态断裂呈现以晶面滑移为主的绝热剪切特性。
In order to understand shear fracture and failure characteristics of 18Ni(250)maraging steel, dynamic tensile tests at different strain rates and Taylor impact tests at different impact velocities were performed with the aid of the Hopkinson tensile device.The mechanical behavior of the 18Ni(250)steel under complex force condition and at high loading rate,particularly the role played by the typeⅡfracture toughness to the complex fracture,was investigated.Based on the shear fracture characteristics of this material the typeⅡ dynamic fracture toughness at different loading rates had been emphasized,and the following results have been obtained:with increasing loading rates,the fracture initiation time of 18Ni(250)steel decreases,but the type Ⅱ dynamic fracture toughness constantly increases;the adiabatic shear characteristics,mainly crystal slips,have been observed under the SEM analysis in the post-deformed specimens of the typeⅡ dynamic fracture of 18Ni(250)steel at different loading rates.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2014年第3期412-416,共5页
Journal of Materials Science and Engineering
基金
国防973资助项目(61311602)
