Ⅲ型载荷分量对N80套管钻井用钢断裂韧性的影响

Influence of Mode Ⅲ Loading Component on the Fracture Toughness of N80 Casing-drilling Steels

采用PLD-100微机控制电液伺服疲劳试验机、金相显微镜、SEM和EDS等,研究了不同III型载荷分量对N80套管钻井用钢断裂韧性的影响。试验结果表明:N80钢由铁素体、上贝氏体和回火索氏体3种不同的显微组织构成。由于断口形貌的不同,在不同III型载荷分量下,N80钢具有不同的总体断裂韧性;III型断裂韧性分量和I型断裂韧性分量之间呈线性相关性。

The influence of different mode Ⅲ loading component on the fracture toughness of N80 casing-drilling steels was studied by PLD- 100 electro-hydraulic servo fatigue testing machine, metallurgical microscope, SEM, EDS and so on. The results show that N80 steel is composed of three different microstructure including ferrite, bainite and tempering sorbite.The N80 steel possesses different total fracture toughness under the different mode Ⅲ loading component. This can be attributed to the fractography. The relationship between the mode Ⅲ and mode Ⅰ fracture toughness component is linear.