Deep hole boring process of cross-pierced tube blanks of high-alloy large-diameter seamless steel tubes

Abstract

The invention relates to the producing and manufacturing process of high-alloy large-diameter seamless steel tubes, in particular to a deep hole boring process of cross-pierced tube blanks of the high-alloy large-diameter seamless steel tubes. A boring machine tool carries out central full piercing on high-alloy continuous casting solid round tube blanks so as to remove central cracks and middle loose areas of the tube blanks, and high aluminum fiber cotton blocks the holes in the two ends of the tube blanks. Because the high-alloy continuous casting solid round tube blanks need to be heated after the process is completed, the high aluminum fiber cotton is used for blocking the holes in the two ends of the tube blanks before the process is implemented, the inner surfaces of the tube blanks are prevented from being oxidized seriously in heating, and the inner surface quality of punched tubular billets can be greatly improved. Meanwhile, by carrying out central full piercing on the high-alloy steel continuous casting solid round tube blanks, cross piercing of the tube blanks can be promoted, the net rolling time is shortened, the service life of tools and dies is prolonged, the rhythm of production is accelerated, and the production cost is lowered.

Description

technical field [0001] The invention relates to a production process of a high-alloy large-diameter seamless steel pipe, in particular to a production process of a high-alloy large-diameter seamless steel pipe such as P91 / P92. Background technique [0002] P91 / P92 and other high-alloy continuous casting round billets have central cracks and a large central loose area (about 13%-15% of the cross-section of the round billet, located in the center of the round billet), after heating, cross-rolling, piercing and rolling Defects such as cracks and folds on the inner surface of the back capillary are very serious, and the reject rate is high. The high-temperature plasticity of high-alloy steel is relatively poor, and the cross-rolling piercing is relatively difficult, the consumption of tools and dies is large, and the production cost is high. Contents of the invention [0003] The object of the present invention is to overcome the deficiencies of the prior art and provide a de...

AI Technical Summary

Problems solved by technology

The high-temperature plasticity of high-alloy steel is relatively poor, the cross-rolling piercing is relatively difficult, the consumption of tools and dies is large, and the production cost is high