Use, Requirements And Manufacture Of Stainless Steel Bent Pipes

Scope of use:
Because the elbow has good comprehensive performance, it is widely used in chemical industry, construction, water supply, drainage, petroleum, light and heavy industry, freezing, health, water heating, fire fighting, electricity, water supply, water supply and water supply.
Aerospace, shipbuilding and other basic projects.
Technical requirements:
Required control of curvature radius. For example, if the radius length is 1.5D, then the radius of curvature must be within the required tolerance. Since most of these pipe fittings are used for welding, in order to improve the quality of welding, the end is beveled, leaving a certain Angle, with a certain edge, this requirement is also relatively strict, how thick the edge, how much the Angle and the deviation range are specified.
There are many more items than pipe fittings in geometric size. The surface quality and mechanical properties of the elbow are basically the same as those of the pipe. In order to facilitate welding, the material of the steel of the pipe to be connected is to be
The same.
Production points:
Stainless steel elbow
1, the electrode should be kept dry when used, titanium calcium type should be dried at 150 ° C for 1 hour, low hydrogen type should be dried at 200-250 ° C for 1 hour (can not be repeated drying, otherwise the coating is easy to crack and peel), to prevent the electrode coating sticky oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the welds. When the elbow is welded, it is subjected to repeated heating to precipitate carbide, which reduces corrosion resistance and mechanical properties. The hardening property after welding is large and cracks are easy to occur. If the same type of electrode is used for welding, it must be preheated above 300 ° C and gently cooled after welding at about 700 ° C. If the solder cannot be treated after welding, chrome-nickel stainless steel electrode should be selected.
2, in order to improve the corrosion resistance and weldability of stainless steel elbow and appropriate increase the appropriate amount of stability elements Ti, Nb, Mo, etc., weldability is better, using the same type of chromium stainless steel electrode, should be preheated above 200℃ and after welding about 800℃ tempering treatment. If the solder cannot be heat treated, chrome-nickel stainless steel electrode should be selected.