Sömlösa stålrör tillverkas genom att perforera stålgöt eller fasta rör i grova rör, och sedan varma rullande, kalla rullande eller kallritning .
1. Förberedelse av rörbillets
It is necessary to select suitable steel ingots or solid tube billets as raw materials. After that, according to production requirements, the tube billets are pre-treated by re-inspection, fixed cutting, centering, peeling and other pre-treatment operations to ensure that the quality and size of the tube billets meet the requirements of subsequent processing.
2. uppvärmning
Whether the oblique rolling method or extrusion method is used, the tube billet or steel ingot must be heated first. The purpose of heating is to improve the plasticity of the material, reduce the deformation resistance, and facilitate subsequent perforation and rolling processing. The heated tube billet or steel ingot is used to produce hot-rolled tubes.
3. perforering och förlängning
Oblique rolling method (Mennesmann method): first perforate the tube billet with an oblique rolling roller, and then extend it with a rolling mill. That is, through the action of the oblique rolling roller, a perforation is formed in the center of the tube billet, and then further processed by the rolling mill, so that the tube billet gradually becomes a steel pipe with a certain size.
Extruderingsmetod: Efter uppvärmning av rörbillet eller göt, extruderas den i ett stålrör genom en extruderingsanordning .
4. Kallbearbetningssteg (valfritt)
Stålrör som produceras genom varm bearbetning kan ibland vara kallbearbetad efter behov . Kallbearbetning kan förbättra den dimensionella noggrannheten och bearbetning av stålröret, förbättra materialets mekaniska egenskaper, etc . Det finns två metoder för kallbearbetning:
Kall ritningsmetod
Dra stålröret genom en rörteckning dör för att gradvis tunna och förlänga stålröret och därigenom uppnå den nödvändiga dimensionella noggrannheten och ytkvaliteten .
Kallvalsmetod
Metoden för att tillämpa det heta rullande kvarnen som uppfanns av Munnesmann -bröderna på kall bearbetning för att uppnå ytterligare bearbetning av stålröret .
5. Sömlös bearbetning
The seamlessness of the steel pipe is mainly achieved through tension reduction. The tension reduction process is a continuous rolling process of the hollow base material without a mandrel. Under the condition of ensuring the welding quality of the base pipe, the tension reduction process of the welded pipe is to heat the welded pipe as a whole to above 950 degrees Celsius, and then roll it into finished pipes of various outer diameters and wall thicknesses through a tension reducer (the tension reducer has a total of 24 passes). The hot-rolled steel pipe produced by this process is essentially different from the ordinary high-frequency welded pipe. After being heated by the heating furnace, the metallographic structure and mechanical properties of the weld can be completely consistent with those of the överordnad rör . Dessutom är stålrörets rundhet i rörkroppen genom flera spänningar som minskar kvarnens rullning och automatisk kontroll än den för liknande sömlösa rör .}}}}}}}}}}}}
6. Efterföljande behandling
After completing the above main processing steps, a series of subsequent processing is required for the seamless steel pipe, including solution heat treatment (i.e. annealing), straightening, pipe cutting, pickling or passivation, finished product inspection, labeling, packaging, etc., and finally the qualified seamless steel pipe is shipped out of the factory.
