Backweld method of stainless steel butt welding elbow
Under the rapid trend of market economy, all fields have achieved equal and good growth. The competition in the stainless steel pipe fittings market is also intensifying, as the middle and downstream home of food ingredients, pharmaceutical production and packaging
The harm of stainless steel pipe fittings is also increasing, we should pay more attention to stainless steel butt welding elbows, which cause cracks in stainless steel butt welding elbows, what are the factors, and then we look together
Why do stainless steel butt welded elbows have gaps
In the pipeline, since the tube heat exchanger is not purged and discharged, it causes gas and water droplets to enter during the long-term stop, resulting in the dissolution of titanium tetrachloride gathered in the pipeline and blocking the pipeline
And because the chloride ions in the chloride reduce the corrosion resistance of the material, resulting in the acceleration of corrosion, the residual stress of the elbow is not removed, the burden is not only the work burden generated by the load, but also many of the residual stress generated by the production link.
The solution to the crack of the stainless steel butt welding elbow, in order to ensure the long-term work of the heat exchanger, should be strictly in accordance with the columns and specifications of the relevant heat exchanger field, to carry out the inspection of the existing deficiencies, immediately understand the progress of the deficiencies in the work, choose reasonable countermeasures, and reduce the corrosion of the installation
Strictly follow operating procedures. Process use and process standard have great harm to the corrosion of martensitic stainless steel. Therefore, strict control of material composition, water flow, material temperature, burden, pH value and other process indices.
Adding a corrosion inhibitor in the area allowed by the process standard can remove part of the burden according to the stabilization solution after solid solution, and can also significantly improve the chemical cracking resistance of the material, but the various problems that may be caused by sensitization should be well weighed when considering the selection of such a partial burden removal method.
Backweld method for stainless steel butt welding elbows
In the overweighing of arcing, it should be finished in the slope, and can not arc and arcing on the surface of the bus bar of the pipeline and pipe fittings. Cracks, pores and other phenomena are found in the process of arcing, which should be cleaned in time.
Stainless steel butt welding elbow should be separated from other metals to prevent direct touch when lifting. The method of non-metal material barrier such as padded wood and rubber plate can be selected.
Stainless steel butt welding elbow in continuous welding, the temperature can not exceed 60 degrees Celsius. When positioning welding, the inside of the weld should be filled with argon protection. When cutting can not use the general grinding wheel slice cutting, should use stainless steel butt welding elbow special grinding wheel or plasma cutting.
When the stainless steel butt welded elbow pipe and non-stainless steel pipe and pipe fittings are connected, the pipe and cavity of the welded butt joint should be filled with argon gas before the bottom welding, and then the tungsten argon arc welding can be carried out. The welds at the joint joints should be pickled and passivated after welding.
