Piercing plug for hot-rolled seamless steel pipe and processing technology thereof

Abstract

The invention discloses a piercing plug for a hot-rolled seamless steel pipe and a processing technology thereof, and the piercing plug is processed by the following components by weight percent (the total weight is calculated by 100%): 0.2%-0.3% of C, 0.3%-0.5% of Si, 0.4%-0.6% of Mn, 1.0%-2.0% of Cr, 1.5%-4.0% of Ni, 2.5%-3.0% of W, 0.5%-1.5% of Mo, 2.0%-4.0% of Co, 0.05%-0.1% of Yb, and the balance of iron and inevitable trace impurities. The axial direction of a die of the plug to be poured is mutually vertical to or parallel to and in coincidence with a main shaft of a centrifuge before pouring, and the nose part of the plug faces outward or downward; and molten metal serially enters into a cavity of the die of the plug during the pouring, the rotational speed of a centrifugal casting machine is not lower than 220rpm, and the rotational speed of the centrifugal casting machine is adjusted in the range of 220-300rpm when molten steel is completely injected into the cavity of the die. The piercing plug has the advantages of uniform and compact structure, good high-temperature strength and excellent thermal fatigue performance, and the service life is 1.5-2 times of that of similar products at home and abroad.

Description

technical field [0001] The invention relates to a processing technology for a seamless steel pipe perforated plug, in particular to a hot-rolled seamless steel pipe perforated plug and its processing technology. Background technique [0002] The piercing plug is one of the most consumed key tools in the production of hot-rolled seamless steel pipes. Due to the harsh working conditions of the piercing plug, when piercing, the working temperature of the plug is as high as 1000 ° C, and at the same time, it also bears huge axial pressure, radial pressure, rotational friction, and rapid cooling and rapid heating thermal stress. The role of mechanical and thermal fatigue. Under such harsh working conditions, the plugs are often scrapped in the form of failures such as flat nose, sticking steel, and cracking. The service life of the plugs is shortened and the frequency of replacement is high, which affects the production efficiency and quality of steel pipes, and has great impact...

AI Technical Summary

Problems solved by technology

Through a lot of theoretical research and practical verification, combined with the different requirements of use, the material of the plug is generally selected from alloy tool steel (such as H13) or alloy structural steel (such as 30CrNi3, 35CrMo, etc.), which are always difficult in terms of high temperature strength and toughness. Reasonable balance, causing various forms of plug failure, affecting its service life

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