Effect of Rare Earth and Cooling Process on Microstructure and Mechanical Properties of an Ultra-Cleaned X80 Pipeline Steel

2020 ◽  
Author(s):  
He Duan ◽  
Yi-Yin Shan ◽  
Ke Yang ◽  
Xian-Bo Shi ◽  
Wei Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Pipeline Steel ◽  
Cooling Process ◽  
X80 Pipeline Steel ◽  
Microstructure And Mechanical Properties

Development and Production of Heavy Gauge X80 and High Strength X90 Pipeline Steels Utilizing TMCP/Optimized Cooling Process

2014 ◽  
Author(s):  
Guodong Zhang ◽  
Xuejun Bai ◽  
Douglas Stalheim ◽  
Shaopo Li ◽  
Wenhua Ding
Keyword(s):  
Mechanical Properties ◽  
Natural Gas ◽  
Pipeline Steel ◽  
Steel Plates ◽  
Plate Mill ◽  
Cooling Process ◽  
X80 Pipeline Steel ◽  
Natural Gas Transmission ◽  
Transmission Pipeline ◽  
Pipeline Project

Along with the increasing demand of oil and natural gas by various world economies, the operating pressure of the pipeline is also increasing. Large diameter heavy wall X80 pipeline steel is widely used in the long distance high pressure oil and gas transportation in China today. In addition, development of X90/X100 has begun in earnest to support the growing energy needs of China. With the wide use of X80 steels, the production technology of this grade has become technically mature in the industry. Shougang Group Qinhuangdao Shouqin Metal Materials Co., Ltd. (SQS) since 2008 has been steadily developing heavier thicknesses and wider plate widths over the years. This development has resulted in stable mass production of X80 pipeline steel plate in heavy wall thicknesses for larger pipe OD applications. The technical specifications of X80 heavy wall thickness and X90/X100 14.8–19.6 mm wall thicknesses, large OD (48″) requiring wide steel plates for the 3rd West-to-East Natural Gas Transmission Pipeline Project and the third line of Kazakhstan-China Main Gas Pipeline (The Middle Asia C Line) and the demonstration X90/X100 line (part of the 3rd West-East Project) in China required changes to the SQS plate mill process design. Considering the technology capability of steelmaking and the plate mill in SQS, a TMCP+OCP (Optimized Cooling Process) was developed to achieve stable X80 and X90/X100 mechanical properties in the steel plates while reducing alloy content. This paper will describe the chemistry, rolling process, microstructure and mechanical properties of X80 pipeline steel plates produced by SQS for 52,000 mT of for the 3rd West-to-East Natural Gas Transmission Pipeline Project and 5,000 mT for the Middle Asia C Line Project along with 1000 tons of 16.3 mm X90/X100 for the 3rd West-East demonstration pipeline. The importance of the slab reheating process and rolling schedule will be discussed in the paper. In addition, the per pass reductions logic used during recrystallized rough rolling, and special emphasis on the reduction of the final roughing pass prior to the intermediate holding (transfer bar) resulting in a fine uniform prior austenite microstructure will be discussed. The optimized cooling (two phase cooling) application after finish rolling guarantees the steady control of the final bainitic microstructure with optimum MA phase for both grades. The plates produced by this process achieved good surface quality, had excellent flatness and mechanical properties. The pipes were produced via the JCOE pipe production process and had favorable forming properties and good weldability. Plate mechanical properties successfully transferred into the required final pipe mechanical properties. The paper will show that the TMCP+OCP produced X80 heavy wall and 16.3 mm X90 wide plates completely meet the technical requirements of the three pipeline projects.

Effect of Cooling Process on Microstructure and Mechanical Properties of X100 Pipeline Steel

2016 ◽  
Vol 87 (10) ◽  
pp. 1366-1375 ◽  
Author(s):  
Xiao-Guang Zhou ◽  
Cai-You Zeng ◽  
Hao Yang ◽  
Liang-Yu Ma ◽  
Zhen-Yu Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
Cooling Process ◽  
Microstructure And Mechanical Properties ◽  
X100 Pipeline Steel

scholarly journals Effect of heat treatment on the microstructure and mechanical properties of a low-carbon X80 pipeline steel

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
B.C. Acosta-Cinciri ◽  
N.M. López-Granados ◽  
J.A. Ramos-Banderas ◽  
C.A. Hernández-Bocanegra ◽  
P. Garnica-González ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Pipeline Steel ◽  
American Petroleum Institute ◽  
The Other ◽  
Low Carbon ◽  
Electron Backscattered Diffraction ◽  
X80 Pipeline Steel ◽  
Microstructure And Mechanical Properties ◽  
Treatment Conditions

Abstract In this work, the effect of heat treatment conditions on the microstructure and mechanical properties of an American Petroleum Institute (API) X80 steel with a low carbon content of ~0.02% wt., destined for the manufacture of pipelines and pipeline transmission systems by welding, was investigated. Samples were heat treated under different conditions and then were characterized by scanning electron microscopy (SEM), orientation image microscopy (OIM), and electron backscattered diffraction (EBSD). The results showed that when the steel is fastly cooled from the austenitic field (990°C), the mechanical properties increase significantly [ultimate tensile strength (UTS) >1,100 MPa, yield strength (YS) 900 MPa, and elongation 27%] due to the high percentage of martensite (M) present in the microstructure (95%). In contrast, when the cooling rate decreases and the treatment conditions remain at/or above the bainitic/martensitic transformation (from 990°C to 600°C and 450°C), the mechanical properties are decreased by almost 50% because of the decrease in the percentage of martensite (18%). However, the percentage of elongation increases significantly (38%) due to the presence of other micro-constituents resulting from the phase transformation. On the other hand, the best combination of mechanical properties (UTS above 800 MPa and YS between 610 MPa and 720 MPa) was obtained when the steel acquired a dual-phase microstructure [(martensite/austenite)-(ferrite/martensite)] since the amount of martensite is conserved between 45% and 82%, in combination with the other micro-constituent present in the steel that allows us to achieve elongation percentages close to 30%.

Effect of Ti-enriched Carbonitride on Microstructure and Mechanical Properties of X80 Pipeline Steel

2010 ◽  
Vol 26 (9) ◽  
pp. 803-809 ◽  
Author(s):  
Wei Deng ◽  
Xiuhua Gao ◽  
Dewen Zhao ◽  
Linxiu Du ◽  
Di Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Microstructure And Mechanical Properties

Microstructure and Mechanical Properties of X80 Pipeline Steel Backing Welded Joint by Fiber Laser-MAG Hybrid Welding

2013 ◽  
Vol 40 (4) ◽  
pp. 0403002
Author(s):  
雷正龙 Lei Zhenglong ◽  
檀财旺 Tan Caiwang ◽  
陈彦宾 Chen Yanbin ◽  
刘德健 Liu Dejian ◽  
胡席远 Hu Xiyuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fiber Laser ◽  
Welded Joint ◽  
Pipeline Steel ◽  
Hybrid Welding ◽  
X80 Pipeline Steel ◽  
Microstructure And Mechanical Properties
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