高钢级管线钢中大型夹杂物的特性

Characteristics of Large Inclusions in High Grade Pipeline Steel

管线钢中大型夹杂物的存在会对高钢级管线钢的力学、焊接、耐腐蚀等性能产生不利影响,进而给油气输送管道的安全运营带来很大的工程风险。近年来,许多管道工程使用的高钢级管线钢均在金相检测过程中发现了超尺寸大型夹杂物。为了有效降低管线钢中大型夹杂物的存在给管道输送系统带来的风险,对大型夹杂物在冶炼过程中的运动规律进行分析,最终确定D类夹杂物临界尺寸为50μm,B类夹杂物的临界厚度为33μm.

The presence of large inclusions has an adverse effect on the mechanical properties, weldability and corrosion re sistance of the high grade pipeline steel, and then it will bring a huge risk to the safe operation of oil and gas transmission pipe lines. In recent years, oversize inclusions have been found frequently during the metallographic examination of high grade pipeline steel used for pipeline projects. In order to reduce the risk to a minimum extent,it is quite necessary to analyze and study the mo tion characteristic of large inclusions during the smelting process. The critical diameter of D type inclusions is determined to be 50 μm,and the critical width of B type inclusions is determined to be 33 μm.