Steel for mandrel pipe mill mandril and preparation technology thereof

Abstract

The invention relates to steel for a mandrel pipe mill mandril and a preparation technology thereof. An alloy component of the steel comprises: by mass, 0.20 to 0.40% of C, less than or equal to 0.6% of Si, 0.7 to 1.3% of Mn, 2.8 to 3.8% of Cr, 0.30 to 0.60% of Mo, 0.20 to 0.50% of V, 0.01 to 0.07% of Nb and the balance Fe and unavoidable impurity elements, wherein the unavoidable impurity elements comprise less than or equal to 0.015% of S, less than or equal to 0.015% of P and less than or equal to 30 ppm of O. The steel is subjected to electro-smelting, electroslag remelting, annealing, forging and annealing and then has good machining properties. The steel is subjected to heat treatment of quenching and high-temperature tempering and then has good high temperature intensity and hardness and a great thermal conductivity coefficient, wherein the thermal conductivity coefficient is great than or equal to 34W / (M.K) (20 to 400 DEG C) and is 40% higher than a thermal conductivity coefficient of steel H13.

Description

technical field [0001] The invention relates to a novel high heat conduction continuous rolling tube mandrel rod material. The steels currently on the market are high-alloy hot work die steels such as H13 and H11, while the steel involved in the present invention is a medium-low alloy steel. Its characteristic is that on the basis of the hardness and toughness of general mandrels such as H13 steel, it has high thermal conductivity, can obtain lower surface temperature, and increase thermal fatigue resistance. Background technique [0002] In 1978, the world's first large-diameter MPM continuous rolling mill was completed and put into production at the Italian Dalming Steel Pipe Plant. The emergence of MPM has developed the continuous rolling pipe technology to a new level. Due to the many advantages of MPM in technology, product quality and production efficiency, it has been rapidly promoted and applied all over the world once it came out. Especially since the 1980s, influ...

AI Technical Summary

Problems solved by technology

Secondly, according to foreign experience, a professional large-tonnage fast forging machine with dual manipulators is required for the production of slender and large-scale die steel products such as mandrel rods, and there is almost no such professional equipment in China.

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