Rare earth treated low-cost high-toughness low-temperature pressure vessel steel plate and production method thereof

Abstract

The invention provides a rare earth treated low-cost high-toughness low-temperature pressure vessel steel plate and a production method thereof. The rare earth treated low-cost high-toughness low-temperature pressure vessel steel plate comprises the following components: 0.10-0.16% of C, 1.20-1.60% of Mn, 0.20-0.50% of Si, less than or equal to 0.020% of P, less than or equal to 0.005% of S, 0.015-0.025% of Nb, 0.010-0.020% of Ti, 0.020-0.040% of Alt, 0.0020-0.0040% of La+Ce, less than or equal to 20 ppm of O, the balance of Fe and unavoidable inclusions. Through the microalloy elements Nb andTi and trace rare earth alloy, the low-temperature toughness of steel is further improved. Rare earth steel is produced by strictly controlling the O content and the S content of molten steel, the Cacontent in the molten steel is kept at a high level through calcium treatment in the later period of smelting, continuous casting and batch production of the rare earth steel are achieved, and the problem that the rare earth steel is unstable in performance is solved.

Description

technical field [0001] The invention belongs to a pressure vessel steel plate and a manufacturing method thereof, in particular to a low-cost, high-toughness low-temperature pressure vessel steel plate treated with rare earths and a production method thereof. Background technique [0002] Steel plates for pressure vessels are specially used to manufacture containers or other equipment for petroleum, chemical, gas separation, storage and transportation. With the rapid development of the national economy, the petrochemical industry has more and more requirements for the strength, plasticity and toughness of pressure vessel steel. The higher the temperature, the higher the requirements especially for the low temperature toughness of the pressure vessel steel. [0003] In order to overcome the increasingly severe low-temperature service conditions, the commonly used method is to add expensive Ni alloys. In "GB3531-2014 Steel Plates for Low-Temperature Pressure Vessels", the cont...

AI Technical Summary

Problems solved by technology

Although this patent can meet the toughness requirements at -80°C, its disadvantage is that Ni, Cr, Nb, V and other alloying elements are added at the same time, and the cost of the alloy is too high

[0008] At present, the main problems of low-temperature pressure vessel steel plates are: high alloy cost: there are many kinds of precious alloys added, and the alloy content is large; Unable to meet usage requirements

Images