Effect of the Volume Fraction and Grain Size of Polygonal Ferrite on the Fracture Properties of Drop Weight Tear Test of Pipeline Steel

2011 ◽  
Vol 47 (24) ◽  
pp. 44 ◽  
Author(s):  
Qingbo YU
Keyword(s):  
Grain Size ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
Polygonal Ferrite ◽  
Fracture Properties ◽  
Drop Weight ◽  
Drop Weight Tear Test

The Effect of Microstructure on Properties of High Deformation Pipeline Steel X70

2013 ◽  
Vol 690-693 ◽  
pp. 182-185 ◽  
Author(s):  
X.L. Wan ◽  
K.M. Wu ◽  
Z.H. Xia
Keyword(s):  
Impact Toughness ◽  
Small Proportion ◽  
Pipeline Steel ◽  
Polygonal Ferrite ◽  
Yield Ratio ◽  
High Deformation ◽  
Drop Weight Tear Test ◽  
Nb Microalloying ◽  
Shear Area ◽  
The Impact

A high deformation pipeline steel X70 with low yield ratio of 74% was achieved has been processed on an industrial scale. The impact toughness of the investigated steel is 388.3 J/cm2 at -20°C and the shear area is 97% in drop weight tear test at -15°C. The microstructure of the steel constisted of primarily acicular ferrite, polygonal ferrite and a small proportion of scattered martensite-austenite constituents. The high deformation pipeline steel had low yield ratio and good toughness, which was attributed to high Nb microalloying and rapid cooling in the TMCP process.

Abnormal fracture appearance in drop-weight tear test specimens of pipeline steel

2008 ◽  
Vol 483-484 ◽  
pp. 239-241 ◽  
Author(s):  
Zheng Yang ◽  
Chang-Boo Kim ◽  
Yaorong Feng ◽  
Chongdu Cho
Keyword(s):  
Pipeline Steel ◽  
Drop Weight ◽  
Drop Weight Tear Test ◽  
Fracture Appearance

Microstructure and Mechanical Properties Analysis of X70 Pipeline Steel with Polygonal Ferrite Plus Granular Bainite Microstructure

2012 ◽  
Vol 161 ◽  
pp. 67-71 ◽  
Author(s):  
Zhan Zhan Zhang ◽  
Xiu Rong Zuo ◽  
Yue Yue Hu ◽  
Ru Tao Li ◽  
Zhi Ming Zhang
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
High Strength ◽  
Polygonal Ferrite ◽  
Granular Bainite ◽  
X70 Pipeline Steel ◽  
Microstructure And Mechanical Properties ◽  
Drop Weight ◽  
Bainite Microstructure ◽  
Strength And Toughness

Microstructure and mechanical properties of X70 pipeline steel with polygonal ferrite plus granular bainite were characterized using tensile tests, Charpy V-notch impact tests, drop weight tear tests, hardness tests and scanning electron microscopy. The results of experiment indicated that X70 pipeline steel with polygonal ferrite plus granular bainite showed an excellent combination of high strength and toughness. The base metal with polygonal ferrite plus granular bainite microstructure exhibited perfect mechanical properties in terms of the transverse yield ratio of 0.81, elongation of 46%, an impact energy of 335 J at -10 °C and a shear area of 90% at 0 °C in the drop weight tear test. The heat affected zone contained coarse grain zone and fine grain zone, which exhibited good low temperature toughness of 216 J at -10 °C. The weld metal primarily consisted of intragranularly nucleated acicular ferrites which led to the high strength and toughness.

Research of the DWTT Fracture of X70 Pipeline Steel

2012 ◽  
Vol 535-537 ◽  
pp. 643-646
Author(s):  
Ying Sun
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Pipeline Steel ◽  
Polygonal Ferrite ◽  
Ferrite Content ◽  
X70 Pipeline Steel ◽  
The Difference ◽  
Shear Area ◽  
Area Percentage ◽  
Different Content

The DWTT fracture toughness of X70 pipeline steel with different content and grain size of polygonal ferrite was investigated. The results show that when the content of polygon ferrite is above 28%, the shear-area percentage of DWTT fracture begins to decrease instead of increase, while polygonal ferrite toughening effect weakens. It is the difference of the polygonal ferrite content that results in the difference of shear-area percentage of DWTT fracture.

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

Microstructural Control of Ductile Crack Propagation in TMCP HSLA Pipeline Steels

2014 ◽  
Vol 922 ◽  
pp. 568-573
Author(s):  
Victor Carretero Olalla ◽  
N. Sanchez Mouriño ◽  
Philippe Thibaux ◽  
Leo Kestens ◽  
Roumen H. Petrov
Keyword(s):  
Grain Size ◽  
Crack Propagation ◽  
Volume Fraction ◽  
Main Role ◽  
Charpy Test ◽  
Initiation And Propagation ◽  
Average Grain Size ◽  
Main Disadvantage ◽  
Steel Grades ◽  
Increasing Demand

Control of ductile fracture propagation is one of the major concerns for pipeline industry, particularly with the increasing demand of new control rolled steel grades required to maintain integrity at high operational pressures. The objective of this research is to understand which microstructural features govern crack propagation, and to analyse the effect of two of them (average grain size, and volume fraction of pearlite). The main disadvantage during classical Charpy test was to discriminate the crack initiation and propagation energy during fracture of a notched sample. The initiation appears to be caused by the stress state in the neighbouring of Ti-containing precipitates or pearlite particles (no presence of M/A constituents or MnS inclusions was detected in the evaluated grades), propagation-arrest of the crack is assumed to play the main role concerning the control of fracture. Our approach to characterize the fracture resistance is to measure the energy absorbed during the crack propagation stage by means of load-displacement curves obtained via instrumented Charpy test. It was observed that the energy absorbed during crack propagation is not influenced by the average grain size but by the fraction and the morphological (banded-not banded) distribution of second pearlitic phase. This suggests that a different approach to characterize the heterogeneities in grain size clustering might be followed to correlate the energy measured during crack propagation and the morphological features of the steel.

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