Steel for low-temperature and high-pressure pipeline connector and manufacturing method of continuous casting round billet thereof

Abstract

The invention relates to steel for a low-temperature and high-pressure pipeline connector and a manufacturing method of a continuous casting round billet thereof. The steel for the low-temperature and high-pressure pipeline connector disclosed by the invention comprises the following components by weight percent: 0.12-0.16% of C, 0.15-0.30% of Si, 1.20-1.45% of Mn, P not more than 0.025%, S not more than 0.015%, 0.15-0.25% of Cr, 0.04-0.10% of V, 0.02-0.05% of Nb, 0.015-0.040% of Alt, H not more than 2.0*10<-4>%, 120*10<-4>% to 260*10<-4>% of N, T.O not more than 15*10<-4>%, and the balance being Fe and inevitable impurities. The steel for the low-temperature and high-pressure pipeline connector provided by the invention has the advantages that the cleanliness is high, components are stable, the welding property is excellent, the strength, the tenacity and the low-temperature impact tenacity are high, and the like.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a steel for low-temperature and high-pressure pipeline connectors and a method for manufacturing the steel for continuous casting round billets. Background technique [0002] For long-distance pipelines that transport low-temperature, high-pressure oil and natural gas, it is required that the steel used to manufacture the connecting parts between the pipelines (such as flanges, tees, elbows, valves, etc.) has good welding performance and at the same time Ensure that the interior of the connector can withstand changes in ambient temperature such as high pressure and low temperature, as well as the complex forces caused by vibration, self-weight and external load, and geographical location. Therefore, the steel used to manufacture the above-mentioned pipe connectors must have good weldability, high strength, good plasticity and toughness, especially good low-temperat...

AI Technical Summary

Problems solved by technology

However, the above-mentioned steels have the disadvantage of unstable low-temperature performance, especially the low-temperature (≤-51°C) impact toughness fluctuates greatly and is low, which is difficult to meet the requirements, which has become a bottleneck restricting the steel for the above-mentioned connecting parts.

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