Rare earth treatment Low -cost high toughness Low -temperature pressure vessel steel plate and its production method

Abstract

The rare earth-treated low-cost, high-toughness, low-temperature pressure vessel steel plate and a production method thereof provided by the invention are composed of: C0.10-0.16%, Mn1.20-1.60%, Si0.20-0.50%, P≤0.020%, S ≤0.005%, Nb: 0.015-0.025%, Ti: 0.010-0.020%, Alt: 0.020-0.040%, La+Ce: 0.0020-0.0040%, O≤20ppm, the rest are Fe and inevitable inclusions. The low temperature toughness of steel is further improved by microalloying elements Nb, Ti and trace rare earth alloys. The rare earth steel is produced by strictly controlling the content of O and S in the molten steel. In the later stage of smelting, the Ca content in the molten steel is kept at a high level by calcium treatment. Stability issue.

Description

technical field [0001] The invention belongs to a pressure vessel steel plate and a manufacturing method thereof, and particularly relates to a rare earth treated low-cost, high-toughness, low-temperature pressure vessel steel plate and a manufacturing method thereof. Background technique [0002] Steel plates for pressure vessels are specially used for the manufacture of petroleum, chemical, gas separation and storage and transportation vessels or other equipment. 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 it is, especially the higher requirements are placed on the low temperature toughness of the pressure vessel steel. [0003] In order to overcome the increasingly severe low-temperature service conditions, the current commonly used method is to add expensive Ni alloys. In "GB3531-2014 Steel Plates for Low-Temperature Pressure V...

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

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