Nickel-free micro-alloy low-temperature pressure vessel steel and manufacturing method thereof

Abstract

The microalloy steel without Ni for low temperature pressure container consists of C 0.04-0.08 wt%, Si less than 0.6 wt%, Mn 1.0-1.6 wt%, Nb 0.010-0.030 wt%, Ti 0.005-0.030 wt%, V less than 0.070 wt%, Al 0.004-0.060 wt%, N less than 0.008 wt%, P less than 0.015 wt%, S less than 0.010 wt%, and Fe and inevitable impurity for the rest. By means of reasonable alloy component design and technological process including TMCP rolling, the steel plate has yield strength up to 360 MPa, tensile strength over 490 MPa, high low temperature impact toughness, excellent plasticity and welding performance, low production cost and short production period.

Description

technical field [0001] The invention relates to a pressure vessel steel manufacturing technology, in particular to a Ni-free micro-alloyed low-temperature pressure vessel steel and a manufacturing method thereof. Background technique [0002] Pressure vessels are widely used in chemical industry, petroleum, machinery, power, metallurgy, nuclear energy, aviation, aerospace, marine and other departments. It is an indispensable core equipment in the industrial production process and an important symbol of a country's equipment manufacturing level. Pressure vessel steel plates are a large category of special high value-added products in thick plates. Steel for pressure vessels used to store and transport low-temperature liquids such as liquefied petroleum gas and liquefied natural gas requires steel plates to have excellent strength and toughness, especially for low-temperature impact toughness. Traditional steel plates mainly improve low-temperature toughness by adding Ni, an...

AI Technical Summary

Problems solved by technology

[0011] Chinese patent 00121259.1 discloses "an ultra-low carbon micro-alloyed high-strength steel", which uses Nb and Ti as micro-alloying elements, and the carbon content in the steel is very low, controlled between 0.005-0.015%. There is no specific rolling process parameter, The main purpose of the steel grade is to obtain high strength, and its yield strength is required to exceed 800MPa, and the toughness index is not mentioned