Alloy Content on Mechanical Properties Research Based on Industrial Big Data Analysis in Microalloyed Steel

Abstract

The pipeline steel for the third-line engineering of West-East was successful produced in Benxi Steel, based on their hot strip mills equipment advantage. However, the impact toughness was unstable during the production. In this research, optical microscope, scanning electron microscopy (SEM) and energy dispersive analysis (EDS) test were used to study on the relationships between different alloy content and microstructure in pipeline steel. What's more, the effect of alloy content on strength and impact toughness in pipeline steel was explored based on the statistics of alloy composition and the mechanical properties in production. The results show that, the alloying elements in pipeline steel can be divided into three categories in this condition. First, Ni, Cu and Mo alloy elements promote the MA constituents transformation, and leading the impact toughness decreases. So, it should be appropriate to reduce the content of these alloy elements, or improvement the cooling process. Second, Cr and Mn alloy, which have no significant effect on both strength and impact toughness, should be appropriately control its content. And third, Nb and Ti micro-alloying, which is particularly improving both strength and impact toughness in pipeline steel. This study is not only provided a basis to improve pipeline steel impact toughness, but also provided the necessary theoretical support for the research and development of higher grade pipeline steel.