Spiral steel pipe typically occurs wall thickness errors, in order to avoid these problems and to obtain more accurate pipe, always pay attention in production process.
Roll from the center of the guide must be from the rolling line. Guarantee from the centerline of the guide rollers and in piercing and rolling from the center line, ie upper and lower rollers from equal distance about equal to the guide.
Galvanized pipe mandrel to choose and the thick walled tube processing, galvanized steel Specifications for the smaller size of the mandrel can be used instead of a solid billet. Uniform thickness of the thick-walled tubes and solid blanks, you can make the probability of a significant reduction in the mandrel bending deformation, can effectively improve the precision of the thickness of spiral steel pipe. Slenderness mandrel precision mandrel is relatively large, generally use the first car to break the outer diameter of the mouth and then welding, or using a long material directly Turning molding. Mandrel outer precision control ± 0.1mm, straight mandrel deviation of not more than 5mm. When welding, the mandrel is inserted between the two sections of a positioning pin of finishing, in order to prevent total straightness tolerances from welding too large.
Quality galvanized pipe has always been subject to focus attention of the masses, for the detection process, the most important of which is galvanized steel application performance Bale. Inflection point refers to the phenomenon of galvanized steel metal material having a yield, the degree of bending of the sample is very important in the initial shaping of galvanized steel, because this can test out of galvanized steel by external pressure when the reaction, if the test out the plating zinc critical point pressure pipe, according to customer requirements can be properly galvanized steel reinforcement to greater affordability. When galvanized pipe drops occur, it should distinguish between the lower yield point. The yield point and the yield stress is the maximum force before the first drop of the sample occurred; lower yield point refers to when excluding the initial transient effects, the yield phases of minimum stress. Hardness index mainly metal materials ability to resist a hard object surface indentation, known as hardness. Depending on the test methods and scope, galvanized pipe can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. Commonly used for pipe Brinell, Rockwell, Vickers hardness of three. Quality galvanized steel is considered by many aspects of the production also has some technical, if not effectively detect the quality of galvanized steel so I suggest that the manufacturers do not ship to the buyer.
Optimum efficiency control of high frequency welded pipe in welding process
In most cases, optimized welding process, power loss can be reduced 50% and can improve the welding quality, reduce downtime, increase production.
Stress on the trench corrosion of high-frequency straight seam resistance welding pipe
Trench etching is generally believed that acute heat in the welding process, the results of local tissue metal and chemical change caused by quenching.
Technology of straight seam high frequency resistance welded steel pipe
Factors that affect the raw material for the steel pipe welding quality affect the quality of raw materials are mainly steel mechanical properties unstable surface defects and strip geometry deviation big three aspects, therefore, we should focus on these three aspects of control.
