Analysis method of residual stress in retained austenite mixed with martensite microstruture of carburized steel alloy surface

摘要

PURPOSE: A method for measuring residual stress in austenite is provided to precisely predict a fatigue life of parts by measuring residual stress in austenite existing in the surface of a carburized alloy metal. CONSTITUTION: An X-ray diffractometer is used to measure residual stress in the surface of an alloy metal. X-ray is radiated onto the surface of the austenite existing on the surface of the alloy metal by using an X-ray generator(12) of the X-ray diffractometer. At this time, the X-ray is radiated onto the surface of the alloy metal such that the X-ray has an incident angle(2theta) of 119 to 149.8deg. by moving a goniometer(11), thereby measuring a maximum diffraction angle. By using the maximum diffraction angle, a delta(2theta)/delta(sin¬2pi) is calculated. Then, the resultant value is multiplied by a stress constant K of the austenite.