Hot rolling seamless steel pipe mandrel

Abstract

The present invention discloses a hot rolling seamless steel pipe mandrel, wherein the chemical components of the mandrel comprise, by weight, 0.4-0.5% of C, 0.2-0.4% of Si, 0.8-1.0% of Mn, 3.2-3.4% of Cr, 4.5-5.5% of Ni, 3.2-3.4% of W, 0.4-0.6% of V, 1.1-1.3% of Co, 0.1-0.3% of Al, 0.15-0.25% of Ce, and the balance of Fe and unavoidable impurities.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a mandrel for hot-rolling seamless steel pipes. Background technique [0002] The mandrel 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 mandrel, when piercing, the working temperature of the mandrel is as high as 1000°C, and at the same time, it must bear huge axial pressure, radial pressure, rotational friction, and rapid cooling and heat stress. The role of mechanical fatigue and thermal fatigue. Under such harsh working conditions, mandrels are often scrapped in the form of failures such as nose collapse, sticking to steel, and cracking. The service life of mandrels is shortened and the frequency of replacement is high, which affects the production efficiency and quality of steel pipes and has a large-scale impact on the organization. Both the production of seamless ste...

AI Technical Summary

Problems solved by technology

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