加载速率对低合金钢缺口断裂行为的影响  

Influence of Loading Rate on Fracture Behavior of Notched Specimens Made of Low Alloy Steel

作　　者：任学冲[1] 田建军[1] 王国珍[2] 褚武扬[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]兰州理工大学材料科学与工程学院

出　　处：《北京科技大学学报》2004年第5期533-537,共5页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(No.59871015)

摘　　要：通过对低合金钢(FCW-62)在-100℃1-500mm/min不同加载速率下缺口试样四点弯曲实验及断裂应的测量,研究了加载速率对低合金钢缺口试样断裂行为的影响.结果表明:加载速率较低时,断裂应力较高;加载速率较高时,断裂应力较低.断裂应力的变化是由断裂的临界事件随加载速率的变化引起的,并且当临界事件相同时断裂应力不随加载速率变化.当加载速率在30mm/min左右时,缺口韧性随加载速率的增加迅速下降,这是由于断裂应力在此时发生了突然改变.The four-point bending (4PB) test of notched specimens made of a low alloy steel (WCF-62) was carried out at different loading rates at -100°C. The local cleavage fracture stress σf was measured. The Influence of loading rate on fracture behavior of the notched specimens was investigated. It is found that at a low loading rate v &le 10 mm/min, σf is about 1100 MPa, while at a high loading rate v ≥ 120 mm/min, σf is about 700 MPa. The change of σf is caused by the change of critical events with loading rate, and if the critical events are identical, σf does not vary with loading rate. When the loading rate is about 30 mm/min the notch toughness decrease sharply with the rising of loading rate due to an abrupt change of σf.

关 键 词：解理断裂 断裂应力 加载速率 缺口韧性 低合金钢 

分 类 号：TB301[一般工业技术—材料科学与工程]