After the analysis and research on the detection system of slab welded pipe seam quality, this paper introduce the system of defecting welded pipe seam quality based on the eddy current crack detection and automatic elimination to welded pipe with fault in seam.

Review of research on friction stir welding defects;

Fuzzy assessment of the influence resulted from welding defects on structural fatigue life based on the method of artificial neural network;

Fatigue life prediction for butt welds of 30CrMnSiNi2A steel containing welding defect;

In order to detect weld defects in steel tube,we set up a realtime imaging and detecting system.

The result shows that the ring weld has weld defects and under alternating stress it will crack,which will finally cause breaking of the urea synthetic tower.

Pointing to the circumferential weld of miltilayer warping high pressure vessel had weld defects out of the allowance and cylinder shells on its both sides were loosed.

Processing the aluminum weld image from the scanning of the X ray negative can derive the binary image of the weld defects.

Fatigue reliability evaluation for welding construction containing welding defects;

According to on site construction practice in recent years,the features and welding defects of industrial pure Ni equipment and pipes and the causes induced are analyzed.

According to the on-site tests in resent years,this article analysed the characteristics and welding defects of chemical Zr mini-containers.

Final,gives an analysis of forming cause of welding seam defect and puts forward some preventing measures.