Seamless steel tube mill
Date:2018-07-30 View:812 Tag:Seamless steel tube mill
Capillary rolling is the main deformation process of seamless steel tube production. Its function is to make the wall thickness of the capillary close to or reach the thickness of the finished tube wall, and eliminate the non-uniform thickness of the longitudinal wall generated by the capillary in the process of perforation. The surface quality of the internal and external parts of the waste pipe is controlled, and the outer diameter and roundness of the waste pipe are controlled. The hollow capillary is rolled into a waste pipe near the final size.
1. automatic tube winding machine: automatic tube rolling machine is a double roller irreversible vertical mill. The utility model is characterized in that a pair of high-speed reverse rotating return rolls are arranged behind the work rolls, and the function of the reverse rotating return rolls is to send the capillary tubes which are wound once to the front. For the second rolling, its production efficiency is low, and most of the domestic units have been modified or eliminated. The material of rollers is mainly chilled cast iron, ductile iron or chilled ductile iron, and the hardness is higher than HSD50.
2, double roll mill: continuous rolling mill is a more advanced steel tube rolling mill. It puts the porous capillary on the long mandrel, which is arranged on a number of frames in turn, and the joint of the adjacent frame roll is 90 degrees. The continuous pipe mill is rolled. The main material of the continuous roll is Ni Cr Mo infinite cold hard ductile iron (also known as Pearlite Nodular Cast Iron), nickel molybdenum infinite cold hard ductile iron (also called acicular nodular cast iron), and the hardness of the pore type is HSD50-65. The first frame of continuous rolls designed abroad is made of forged steel or graphite steel to further improve the strength of rolls.
3. three roll continuous rolling mill: the three roll adjustable limit mandrel mill (PQF) developed by the Italy INNSE company overcomes the inherent limitation of the double roll mill because it will be 360 degrees. This type is divided into three parts, which reduce the difference of linear velocity between the bottom and the edge of each roll hole type, so the rolled steel pipe has high precision. The continuous rolling of a small PQF mill is a whole. Using Ni - Cr - Mo indefinite cold hard ductile iron. The hardness is controlled in HSD55-65. Assembly of large PQF mill continuous roll, that is, roll is wear resistant. It is better to use nickel chromium molybdenum infinite cold hard ductile iron. The shaft is made of high strength forged steel material and can be reused after quenching and tempering, which greatly saves the cost. The structure has been successfully applied to the Tianjin steel pipe company.
4. Assel rolling mill: Assel rolling mill is a three roll cross rolling, consisting of three active rollers and a mandrel. The roller is divided into four parts: the inlet cone, the roller shoulder, the flat area and the outlet cone. The material is made of 4Cr5MoSiV1 forged steel, cast semi steel or alloy nodular cast iron. Heat treatment hardness: the forged steel roll is controlled in the HSD65-75, the half steel roll is controlled in the HSD50-60, the alloy spheroidal graphite cast iron roller is controlled in the HSD55-65 (this material roller is designed for the import unit, there are few successful application examples in China).