Seamless steel tube for manufacturing hollow core rod and production method

Abstract

The invention relates to a seamless steel tube for manufacturing a hollow core rod and a production method. The seamless steel tube comprises the following components in percentage by mass: 0.28 to 0.33 percent of C, 0.45 to 0.65 percent of Si, 0.40 to 0.60 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.02 percent of S, 3.00 to 3.30 percent of Cr, 0.45 to 0.55 percent of Mo, 0.20 to 0.30 percent of V, less than or equal to 0.15 percent of Cu, less than or equal to 0.20 percent of Ni, and the balance of Fe and unavoidable impurities. The production method comprises the following steps of: blanking a tube blank, heating by using an annular furnace, punching by using a Mannesmann piercing mill, rolling the tube by using a pilger mill, cutting a pilger head, heating by using a walking beam furnace, sizing by using a sizing mill, performing heat treatment, straightening, sawing, performing internal and external surface treatment, performing manual inspection, performing ultrasonic wave and eddy current automatically combined flaw detection, performing manual reinspection, cleaning, identifying and packaging, and warehousing.

Description

technical field [0001] The invention belongs to the production field of seamless steel pipes in the metallurgical industry, and in particular relates to an alloyed high-strength, high-toughness quenched and tempered seamless steel pipe used for manufacturing a hollow mandrel and a production method thereof. Background technique [0002] The mandrel is one of the most important deformation tools of the pipe rolling mill. The mandrel and the roll work together to roll the perforated tube blank into seamless steel pipes of various sizes. The service conditions of the mandrel during the rolling process are very harsh. Its surface is subjected to compressive stress, frictional force, and alternating cold and heat stress. Therefore, the requirements for the performance of the mandrel are very high, and it needs to have high strength, high hardness, high toughness, wear resistance, fatigue resistance and corrosion resistance. At present, most of the large-diameter mandrels used ar...

AI Technical Summary

Problems solved by technology

At present, most of the large-diameter mandrels used are solid and forged, especially the large-diameter mandrels with specifications above Φ280mm are more difficult to manufacture

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