Study On Control Procedures Of Ship Welding Defects Based On Genetic Analysis

An important premise of ships sailing and operating safety is that they are fabricated to have good quality.When there is a serious welding defect at the joint,it is possible for some structures to crack,even leading to a catastrophe like shipwreck in the severe enviroment.Based on research and analysis,the thesis focuses on determining the causes of welding defects by conducting thorough conversation with welding experts and technicians so that the problems they face in their routine work can be understood.After being analyzed and fully understood,the problems can be prevented by precautious proposed accordingly.The survey was conduct by releasing questionnaires.110 questionnaires were dispatched and 104 effective questionnaires were well-received.Referring to the result of survey,most of the welders have a clear recognition of the welding defects which aids to avoid the welding defects during daily work.However,few welders pay enough attention on undercut,overlap,crater,weld size and shape of defects..If these welding defects can not be eliminated,it will result in serious quality problem.Additionally propose the corresponding solutions to the welding defect for avoiding and controlling effectively including the high level skilled workers,the best welding equipment,high quality welding material,strict specification for welding process,proper environment for welding,strict reinspection to the goods after transported into the factory,small amount on trial for welding material,reward and punishment system and on-the-spot supervision.At the same time illustrate in detail for each of them.In addition,analysis and compare the ratio of yield strength to tensile strength in detail for welding material of the vessels.And then add yield ratio in national standards.According to the yield ratio,judge the quality of the goods and compare which is better.And then we can pick over the better one for the suppliers.Describe the importance and necessity in detail and analysis with real cases for small amount on trial for welding material.This can prevent and avoid potential quality risks effectively.And we can deal with the quality problem of welding material after discovering that.Recommend to have reward and punishment system owing to the reason that this can improve morale and make the welding workers have positive attitude into finishing the work.To reward for the workers who finish the work well and punish the workers who can't finish the work well to improve the quality of the goods.Finally we have on-the-spot supervision for the problems.To improve the quality of the goods,we monitor including voltage,electricity,environment temperature,environment humidity which will influence quality of welding.This can effectively control the welding defect of vessels from all of these measures to improve the welding quality of the goods.