Method for improving thick-specification L555M level pipeline steel DWTT property

A thick gauge, pipeline steel technology, applied in the field of improving the DWTT performance of thick gauge L555M pipeline steel, can solve the problems that the low-temperature drop hammer tearing performance is not easy to control, and the performance indicators such as strength and toughness cannot meet the technical standard requirements. Excellent drop weight tear properties, good strength properties, and the effect of increasing rolling deformation

Active Publication Date: 2019-09-06
ANGANG STEEL CO LTD
View PDF12 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Although iron and steel and welded pipe enterprises have accumulated certain experience in the production of high-performance high-grade, large-diameter, and large-wall-thickness pipeline steel, research and trial production of high-grade pipeline steel with a pipe wall thickness greater than 20 mm

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A thick specification L555M grade pipeline steel is composed of the following components in weight percentage: C: 0.04%-0.06%, Si: 0.15%-0.25%, Mn: 1.73%-1.83%, P≤0.015%, S≤0.003% , Nb: 0.06% ~ 0.08%, Ti: 0.008% ~ 0.020%, Mo: 0.14% ~ 0.18%, Ni: 0.20% ~ 0.24%, Cu: 0.10% ~ 0.16%, N: ≤0.008%, the rest is Fe and unavoidable impurities. The specification is: 26.4*3712*12500mm.

[0025] A method for improving the DWTT performance of the thick-gauge L555M grade pipeline steel includes heating, rough rolling, finish rolling, controlled cooling and straightening of a steel billet in sequence to obtain a thick-gauge pipeline steel product.

[0026] 1) Heating stage: limit the heating time and temperature in the high temperature section. ~ 180 minutes, the temperature of the furnace is guaranteed to be above 1200°C;

[0027] 2) Rough rolling stage: the rough rolling adopts the horizontal-longitudinal rolling method, and the horizontal rolling is 4 to 6 passes, and the longitudi...

Embodiment 2

[0034] A thick specification L555M grade pipeline steel is composed of the following components in weight percentage: C: 0.04%-0.06%, Si: 0.15%-0.25%, Mn: 1.73%-1.83%, P≤0.015%, S≤0.003% , Nb: 0.06% ~ 0.08%, Ti: 0.008% ~ 0.020%, Mo: 0.14% ~ 0.18%, Ni: 0.20% ~ 0.24%, Cu: 0.10% ~ 0.16%, N: ≤0.008%, the rest is Fe and unavoidable impurities. The specification is: 27.5*3715*12000mm.

[0035] A method for improving the DWTT performance of the thick-gauge L555M grade pipeline steel includes heating, rough rolling, finish rolling, controlled cooling and straightening of a steel billet in sequence to obtain a thick-gauge pipeline steel product.

[0036]1) Heating stage: limit the heating time and temperature in the high temperature section. ~180 minutes, and the temperature of the oven is guaranteed to be above 1180°C;

[0037] 2) Rough rolling stage: the rough rolling adopts the horizontal-longitudinal rolling method, and the horizontal rolling is 5 to 6 passes, and the longitudin...

Embodiment 3

[0044] A thick specification L555M grade pipeline steel is composed of the following components in weight percentage: C: 0.04%-0.06%, Si: 0.15%-0.25%, Mn: 1.73%-1.83%, P≤0.015%, S≤0.003% , Nb: 0.06% ~ 0.08%, Ti: 0.008% ~ 0.020%, Mo: 0.14% ~ 0.18%, Ni: 0.20% ~ 0.24%, Cu: 0.10% ~ 0.16%, N: ≤0.008%, the rest is Fe and unavoidable impurities. The specification is: 32.1*4335*12000mm.

[0045] A method for improving the DWTT performance of the thick-gauge L555M grade pipeline steel includes heating, rough rolling, finish rolling, controlled cooling and straightening of a steel billet in sequence to obtain a thick-gauge pipeline steel product.

[0046] 1) Heating stage: limit the heating time and temperature in the high temperature section. ~180 minutes, and the temperature of the oven is guaranteed to be above 1180°C;

[0047] 2) Rough rolling stage: the rough rolling adopts the horizontal-longitudinal rolling method, and the horizontal rolling is 5 to 6 passes, and the longitudi...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Tensile strengthaaaaaaaaaa
Login to view more

Abstract

The invention relates to the technical field of pipeline steel pipe production, in particular to a method for improving the thick-specification L555M level pipeline steel DWTT property. The method comprises the steps that firstly, the heating temperature is limited at 1200 to 1250 DEG C, the temperature of a soaking zone is limited at 1190 to 1230 DEG C, the heating main time is limited at 270 to330 minutes, the high-temperature segment time is limited at 120 to 180 minutes, and it is ensured that the tapping temperature is above 1200 DEG C; secondly, the transverse-longitudinal rolling manner is adopted in rough rolling, transverse rolling is carried out for four to six passes, longitudinal rolling is carried out 2 to 4 passes, the initial rolling temperature is not lower than 1150 DEG C, after transverse rolling, after the temperature is 1040 to 1080 DEG C, longitudinal rolling is carried out, meanwhile, it is ensured that the longitudinal rolling accumulative reduction rate is above 55%, the longitudinal rolling single-pass reduction rate is limited as 20%, and the intermediate blank thickness is 80 to 90 mm; thirdly, the initial rolling temperature is 780 to 850 DEG C, the finish rolling and final rolling temperature is 750 to 800 DEG C, and after rolling, the water inlet temperature is 790 to 810 DEG C; and fourthly, the controlled cooling mode is adopted, the water feeding amount is 400 to 500 m<3>/h, the water discharging amount is 1300 to 1400 m<3>/h, 12 to 15 sets are initially rolled, the water ratio is 1/3, the cooling speed is 10 to 20 DEG C/s, and it is ensured that the return red temperature is 420 to 480 DEG C. The thick-specification L555M level low-temperature DWTT property is improved, and the property yield is improved.

Description

technical field [0001] The invention relates to the technical field of pipeline steel production, in particular to a method for improving the DWTT performance of thick specification L555M grade pipeline steel. Background technique [0002] With the rise of the energy industry and the continuous growth of energy demand, the transmission volume and transportation distance of oil and gas pipelines continue to increase. Pipeline construction is increasingly using large-diameter, high-strength, and high-toughness pipeline steel pipes. The technological progress of iron and steel metallurgy and pipeline manufacturing industry has greatly improved the quality, level and service performance of high-performance pipeline steel in my country. The production capacity of steel pipe production lines with X80 steel grade and large wall thickness supply capacity in China has reached 5 million tons / year or more. [0003] Although iron and steel and welded pipe enterprises have accumulated c...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C22C38/02C22C38/04C22C38/08C22C38/12C22C38/14C22C38/16C21D8/02
CPCC21D8/0226C22C38/001C22C38/002C22C38/02C22C38/04C22C38/08C22C38/12C22C38/14C22C38/16
Inventor 姚震张坤李新玲李靖年丛津功王若钢王刚段江涛应传涛
Owner ANGANG STEEL CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap