Fatigue Crack Growth Rate in Weld Metal of Steel HQ-60 Under High Stress Ratio

It is concluded that the residual stress in specimen welds is quite little, through measuring the stress in the HQ-60 steel test plate and specimen. Therefore the residual stress affect on the crack growth rate can be neglected, when crack growth rate of the specimen under high stress ratio is investigated, According to the results of the crack growth tests in the weld metal, a crack growth formula in linear elastic range (LER) is obtained. In the paper a modificative method of stress intensity factor in small scale yielding range is provided, so the formula in LER can be also used, USing the method, life calculation of welded structures can become convenient.