High-carbon equivalent low-temperature high-toughness pipeline steel plate for x80 bent pipe and manufacturing method thereof

Abstract

The invention relates to a pipeline steel plate for X80 steel grade elbow with high carbon equivalent, low temperature and high toughness and a manufacturing method thereof, in particular to a pipeline steel plate for X80 steel grade elbow resistant to high carbon equivalent, low temperature and high toughness. The method has the advantages of simple process and good yield advanced features. The thickness of the steel plate is 18.4-42mm. Its manufacturing process is as follows: proportioning and preparation → smelting in converter or electric furnace → refining outside the furnace → continuous casting → slab reheating → rolling + ACC gradient cooling → straightening. In addition to excellent low-temperature toughness, the steel plate adopted by the patent application has the characteristics of simple and easy to realize process and high yield.

Description

technical field [0001] The invention belongs to the technical field of manufacturing steel plates for X80 bent pipes, in particular to high carbon equivalent steel plates for X80 bent pipes with high carbon equivalent and excellent low-temperature toughness and a manufacturing method thereof. Background technique [0002] At present, petrochemical energy still occupies the dominant position in the energy structure of the energy demanded by the world. The rapid growth of the world economy in recent years has greatly driven the rapid growth of petrochemical energy demand, which has also greatly promoted the development of long-distance transmission pipelines. Efficiency, lower investment, and the development trend of steel for long-distance oil and gas transmission pipelines is to develop towards high-strength or ultra-high steel grades. At present, the highest steel grade of pipeline steel used in countries all over the world is X80 steel grade. In addition to the straight p...

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Problems solved by technology

Due to the deformation at a higher temperature during the entire heat simmering process, while the degree of deformation is small, and the subsequent cooling capacity is weak, Therefore, the hot-simmering steel plate for elbow can only be designed with high carbon equivalent composition! The design of high carbon equivalent will bring two main problems to the whole production: 1) The impact toughness is reduced; 2) Due to the large structural stress in the cooling process, the shape of the steel plate is poor, which brings difficulties to subsequent straightening and affects production at the same time efficiency

High carbon equivalent composition design will result in poor impact toughness of low temperature series

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