Study of the crystallographic texture of pipe steel

Abstract

In the manufacture of large-diameter welded pipes used for the construction of pipelines operating at high pressure, it is extremely important to provide the required mechanical and service characteristics. One of the main tasks of improving the quality of each batch of sheet metal, while maintaining or reducing the cost of production of pipes, is to provide a set of mechanical properties. The problems of obtaining proper mechanical characteristics of sheet products of the widely used 10G2FB steel during its production have been raised for several years. This is explained by the facts that this steel is still used in the construction of trunk pipelines and the technological process for the production of rolled products is a multi-factor system, the accomplishment of each stage of which directly affects the quality. In this paper, we consider issues related to the study of the texture state of samples cut from 6 pipes (from different batches, different manufacturers) made of 10G2FB low-carbon steel in order to construct direct and inverse pole figures and determine the role of texture formation in the properties of the base metal. A comparative analysis of the obtained results of mechanical tests is carried out. A comparison of the test results for impact toughness and crack resistance with the results of texture analysis showed that pipe samples, in the structure of which after rolling the textures were formed, which were determined as maximum when controlling reflections from a series of planes (110), showed the best viscous properties in low temperature impact bending tests and in the entire range of studies in tests for crack resistance.