Abstract
As an important mechanical connection,the threaded connection has a wide range of applications covering many industries such as construction,automotive,aerospace,electric power,petrochemical,etc.The advantages of this type of connection are that it is structurally reliable,easy to connect and disassemble,and cost effective.However,in practice,environmental corrosion,vibration,external impact and other factors will have an impact on the threaded connection,resulting in its failure.This not only leads to equipment damage,but also may cause safety accidents,bringing serious economic losses and casualties to the enterprise.Therefore,carrying out in-depth study of the failure mechanism of threaded connection,and putting forward effective preventive measures accordingly to improve the safety and reliability of equipment are of great practical significance.
Based on the extensive research of relevant literature reports in recent years,the main failure mechanism and preventive measures of thread fracture,thread corrosion and thread wear are analyzed.Various factors such as preload,stress concentration,vibration and environmental conditions are also investigated.Secondly,for the previous thread fracture,thread corrosion,thread wear and other conditions,the various measures to prevent the thread connection failure are summarized,including coating,coating,corrosion inhibitor,heat treatment and surface hardening treatment,and the advantages and disadvantages of these measures are analyzed.Thread fracture usually requires the stress concentration of long hours and the effect of external impact,which can be eliminated by stress and heat treatment,refine the grain,and improve the toughness and plasticity of the material,but the high temperature will decrease the coarse hardness of the grain.Thread corrosion usually reacts with corrosive media in a specific chemical environment.Measures such as using corrosion-resistant materials and applying anti corrosive coating can be taken to isolate the contact between thread pairs and corrosive media.Thread wear is usually due to the role of friction in the working process of thread auxiliary,which can be reduced by coating to isolate the surface contact,or through the surface treatment method to increase the hardness of the material.Adding lubricant and sealing can also reduce wear.Some common daily maintenance and protection means,such as the manufacturing process to ensure the accuracy and surface quality of the thread,regular inspection and maintenance of the thread connection parts,also increase the pretension force,etc.These measures are designed to improve the corrosion,vibration and impact resistance of the risk of failure.
Finally,the current status of Chinese and international research on failure prevention of threaded connection in the last three years is screened and summarized.By comparative analysis,it is found that Chinese and foreign research on failure prevention of threaded connection has achieved certain results,but there are still many problems that need to be solved,such as short protection time,high cost,non-environmentally-friendliness and lack of appropriate testing and diagnostic technology.In the future,it is necessary to continue to study the failure mechanism of the threaded connection,and study the high performance protection materials,green environmental protection technology and intelligent monitoring and diagnosis technology to prevent and reduce the casualties and economic losses caused by the thread failure.关键词
失效分析/螺纹断裂/螺纹腐蚀/螺纹防护Key words
failure analysis/thread fracture/thread corrosion/thread protection分类
金属材料
