Zhang Ming.Influence of Microstructure on DWTT Performance of Thin-wall X65M Pipeline Steel[J].Special Steel,2024,45(05):123-126. DOI: 10.20057/j.1003-8620.2023-00205.
Influence of Microstructure on DWTT Performance of Thin-wall X65M Pipeline Steel
The paper addresses the issue of fluctuating low-temperature drop-weight tear test (DWTT) performance in 6-8 mm thin-wall pipeline steel, the influencing factors of the control process of low-te
mperature DWTT of X65 thin-wall pipeline steel have been explored. With microstructure analysis and numerical deconstruction study of different low-temperature DWTT results, , it reveal that the size of polygonal ferrite grains and the distribution of M/A constituents in the central part of the steel plate significantly affect low-temperature DWTT performance. When the average area of grains with an area ≥200 μm
2
is greater than 260 μm
2
, and the proportion of M/A constituents is greater than 6%, DWTT performance shall deteriorate significantly. By optimizing the composition and continuous casting and rolling processes, control of grain size and M/A constituents can effectively improve the low-temperature DWTT performance of thin-specification pipeline steel. The related product has achieved stable production of more than 80,000 tons, meeting the requirement of -30 ℃ low-temperature DWTT, it is of great significance for the development and production of thin-wall pipeline steel products.
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