用超声瑞利波研究延性启裂

Research on Ductile Incipient Crack by Using Ultrasonic Rayleigh Waves

利用超声瑞科波和 GB2038-80对16Mn 钢进行了延性断裂韧性试验.结果表明,将超声瑞利波探测裂纹的强度法和时延法结合起来,采用脉冲回波重合法,确定的启裂韧性 J_(Ic)更能反映真实情况.同时,根据试验过程超声瑞利波行为的变化特征,还可提供有关裂尖区的屈服状态和裂尖钝化扩展机制的信息.

By applying the ultrasonic Rayleigh waves and GB 2038-80,the ductile fracture toughness test is carried out for steel 16Mn.The results indicate that the measurement of ductile fracture toughness J_(IC)is more accurate by combining the sonic intensity method with the delay time method and by adopting pulse-echo-overlap-method.At the same time,the test procedure also presents the information of yielded state at crack tips and of expended mechanisrn of crack tips passivation by means of changing characteristics of ultrasonic Rayleigh waves.