Reliability distribution of welding defect size

Reliability distribution research on welding defect size is carried out based on physics failure background and mathematical statistics. The research shows that the defect ratio is invariable in a certain weld metal area, which is deduced that welding defect size obeys exponential distribution. By means of least square and correlation coefficient maximum method, it is found that the exponential distribution is the best one for defect size. So it is put forward that exponential distribution is the real reliability distribution for welding defects size.