The stress intensities for slow crack growth in steels containing hydrogen

A test technique has been developed to determine the stress intensity for slow crack growth in hydrogen precharged steels. Measurements on several grades of maraging steel and a 300M steel show that hydrogen contents on the order of 2 ppm reduce the stress intensity for slow crack growth by 50 pct or more of theK _Ic values. At equivalent hydrogen contents the 300M steel was more severely embrittled than the mar aging steels. Comparison of the present results with aqueousK _Iscc data indicates that the amount of hydrogen “picked up by the steels in stress corrosion increases with increasing yield strength. Formerly with International Nickel Co.