Thick-specification wide X65M pipeline steel hot-rolled rolled plate and manufacturing method thereof

Abstract

The invention discloses a thick-specification wide X65M pipeline steel hot-rolled rolled plate and a manufacturing method thereof. The hot-rolled rolled plate is prepared from, by mass percent, 0.06%-0.08% of C, not larger than 0.25% of Si, 1.45%-1.60% of Mn, 0.045%-0.055% of Nb, 0.020%-0.030% of Ti, 0.25%-0.35% of Cr, 0.09%-0.12% of Mo, 0.020%-0.050% of Alt, not larger than 0.015% of P, not larger than 0.008% of S and the balance Fe and inevitable impurities. The thick-specification wide X65M pipeline steel hot-rolled rolled plate is designed through C-Mn-Nb-Ti-Cr-Mo alloy ingredients, and the hot-rolled rolled plate with low cost and excellent comprehensive performance is obtained in combination with a clean steel smelting and TMCP controlled rolling and controlled cooling process.

Description

technical field [0001] The invention belongs to the technical field of exporting high-purity, low-alloy, and high-strength steel products, and specifically relates to a thick gauge and wide width X65M pipeline steel hot-rolled coil and a manufacturing method thereof, in particular to a thick gauge (≥19mm) wide width (≥1850mm ) for seawater desalination transportation welded pipes (such as high-frequency resistance welding or submerged arc spiral welding) L450M / X65M pipeline steel hot-rolled coils and manufacturing methods thereof. Background technique [0002] X65M extreme specification pipeline steel hot-rolled coils are used in the engineering construction of Saudi Arabian seawater desalination project. The project mainly adopts spiral welded pipe with large diameter and large wall thickness. Due to the influence of geographical environment, the coil requires high strength and good performance stability. [0003] Document CN 106282798 A discloses thick X65 pipeline steel ...

AI Technical Summary

Problems solved by technology

The content of C in this document has a wide range and the upper limit is close to the peritectic region, which is not conducive to the quality control of the slab, and the low content of Mn and Nb is difficult to ensure the strength of thick gauge products

And there is no RH vacuum treatment process in the steelmaking process, which is not conducive to the removal of harmful gases, and cannot be applied to the technical conditions of products that require vacuum treatment

In addition, the heating temperature range is large, which is not conducive to the stable control of the temperature in the rolling process, and the high temperature upper limit consumes a lot of energy.

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