Precision steel tube is a kind of high precision steel tube material, through careful or cold rolling process to meet specifications, small diameter precision steel pipe produced by continuous rolling pipe line hot rolled small diameter precision steel tube is a kind of more advanced methods, usually conducted on two-high rolling mill, small diameter precision steel tube in the circular groove and the fixed ring of tapered at the top of the hole in the rolling, cold drawing usually on a single or double chain cold Precision steel tubes drawing machine extrusion, the heating pipe in a closed extrusion cylinder moves with extrusion rod, precision steel pipe is a kind of high precision steel tube material, 16 mn extrusion small diameter precision steel pipe, small diameter size high precision steel pipe hydraulic equipment, good surface finish. Using precision seamless tube manufacturing mechanical structure or hydraulic equipment, can greatly save processing time, improve material utilization, improve the quality of products.
The main disadvantage of cold drawn steel tube?
1. Fold exist on the surface of the cold drawn steel tube surface or the inner surface, straight or spiral, continuous or discontinuous. Fold the main reason is the tube material quality is bad, folding his existence, perhaps surface inclusions, serious scratch and crack, angular in grinding, the extension and appear fold after drawing. In order to prevent the formation of folding, should be improving the quality of pipe material and pay attention to check and grinding.
2. Cracks (including crack, hairline) refers to the inner surface in a straight line on the surface of steel pipe or spiral scattered small crack, 1 m or more than 1 mm in depth, there is continuous and discontinuous. The reason is: hot-rolled tube billet has the subcutaneous bubbles and subcutaneous inclusions, before drawing with cracks or deep pitting on the steel pipe, in the operation of hot rolled or cold drawn each working procedure produced a vertical stroke or scratches. Watch out for the formation of crack also Precision Welded pipes lies in improving the quality of tube material, reinforced pipe material inspection and grinding. At the same time should check proof in cold drawn pipe production process of pitting and scratches.
3. Pit is spreading in the area of the steel pipe surface of varying local sag, spread some periodic, some irregular. Pit occurs because tin oxide or other qualitative hard dirt in the drawing or medium pressure straightening process into the surface of steel tube, is probably already exist in the steel pipe sticking on the surface of the skin peeling. Preparedness of pits is carefully check the shortcomings such as tube material and remove become warped skin, keep the work places, tools and lubricant, such as clean, guard against tin oxide and dirt on steel pipe surface.
4. The diameter of the main reasons of the diameter error is with wrong may ignore the tube drawing die feet provoked changes because of the wear and tear. In the process of straightening straightening roller pressure is too big can also cause the diameter of the steel tube smaller.
5. The wall thickness of the main reasons of wall thickness of mold fitting is wrong, perhaps overlooked mould feet because of the wear and provoked changes, on the wall after the empty lane of wall thickness variation is expected to pull is not correct, use the curved die and conical mandrel for short mandrel drawing the location adjustment wrong - before or after the event. To guard stainless steel 304 pipes against wall thickness error, should be properly with mold, adjust the mandrel. Empty steel tube wall thickness variation in drawing passes should be measured correctly.
6. Oval that steel tube cross-section oval. Used in the process of drawing die is elliptical pipe die pull perhaps in straightening steel pipe two twists and turns his head is too big, in the process of straightening up move up and down too much pushing trendy stuck, steel pipe, steel pipe diameter end of shaking is too large, and the pressure between the straightening roll dispatch inequality will produce this kind of defect. If because die ellipse and shortcomings should change pipe die. If the ellipse is formed in the process of straightening, should be removed when straightening of ellipse related reasons.