microstructure transformation of x70 pipeline steel

(PDF) Influence of heat treatments on the microstructure

In the present work, a novel heat treatment cycle was used to alter the microstructure of base metal (BM), heat affected zone (HAZ) and weld metal (WM) in the welded pipe steel of grade API X70.

A CCT Diagram for an Offshore Pipeline Steel of X70 Type

perature- and microstructure-dependent flow stress for a pipeline steel of X70 type (Ref. 5). This approach requires prior knowledge of the relevant continuous- cooling-transformation (CCT) diagram providing information about the involved phases and the temperatures at which the phase transformations take place during continuous cooling. A bainite transformation kinetics model and its X70 pipeline steel are mainly determined by the nal mi-crostructure, which is affected by the phase transformation. It has been demonstrated that bainite is the predominant microstructure in CGHAZs of X70 pipeline steel [68]. To understand features of the nal microstructure in CGHAZs of X70 pipeline steel, bainite transformation must

A comprehensive study on the microstructure and

Feb 18, 2020 · Many attempts have been made to analyse the microstructure of API X70 steel welded joints. However, there is a lack of a more systematic metallographic investigations comprising the base material, HAZ as well as weld metal with relation to mechanical properties [10,11,12,13,14,15,16,17,18,19,20].Ghomashchi and co-workers [] revealed that the microstructure An Investigation on Microstructural Evolution of X70 Steel Nov 06, 2018 · In the present work, qualitative and quantitative microstructural analysis, hardness and impact test performed and evaluated on samples from X70 line pipe with 3 different steel chemistries. The samples prepared from different locations on body, weld

Anisotropy and microstructural evolutions of X70 pipeline

Macro- and microscale investigations of hydrogen embrittlement in X70 pipeline steel by in-situ and ex-situ hydrogen charging tensile tests and in-situ electrochemical micro-cantilever bending test. Materials Science and Engineering:A, Vol. 772, Issue. , p. 762. Continuous Cooling Transformation Behavior of X70 Pipeline The continuous cooling transformation behaviors were researched on X70 pipeline steel through two pass deformation and non-deformed austenite using Gleeble-3500 thermal mechanical simulator, and static continuous cooling transformation curve and dynamic continuous cooling transformation curve were measured through thermal dilation method and metallographic method.

Correlation of microstructure and fracture properties of

Jul 10, 2005 · Effects of microstructure on fracture toughness and transition temperature of high-toughness X70 pipeline steels were investigated in this study. Three types of steels were fabricated by varying alloying elements such as C, Cu, and Mo, and their microstructures were varied by rolling conditions such as finish rolling temperature and finish cooling temperature. Charpy V-notch (CVN) Effect of Hot Rolled Process on Microstructure and The microstructure and mechanical properties were studied on X70 pipeline steel strips on 1700 Hot Mill produced by Tangsteel using methods of optical microscope, SEM and TEM tensile tests and so on. And effect of impurities in the steel on impact toughness was researched. The results show that microstructure of X70 pipeline steel strips is mainly acicular ferrite of which the grains are about

Effects of Processing Parameters on Microstructure

Achieving fine and uniform grains is the most effective way to enhance strength and toughness, which are required properties for pipeline steels. Steels microalloyed with Nb can exhibit a mixed grain structure, which can deteriorate low temperature toughness. In this work the effects of the thermomechanical processing parameters on the prior austenite grain structure before ferrite Grade X70 - an overview ScienceDirect TopicsDevelopments in linepipe steel metallurgy have kept pace with requirements for increased pipe strength and diameter so that HAZ hydrogen cracking is not a major problem even in X70 grade pipelines, although experience beyond this strength level is still fairly limited (Ref 1, 2). However, high strength pipeline fittings, such as bends, tees

INFLUENCE OF HEAT TREATMENTS ON THE

different zones after arc welding of X70 pipeline steel. This investigation is contribution as some scientific works which have been done on welding of low carbon steel [6-10]. 2 Experimental Material and Techniques The material under investigation was X70 pipeline steel with single-V preparation joints were welded by arc welding. INFLUENCE OF HEAT TREATMENTS ON THE MICROSTRUCTURE This investigation is a contribution to some scientific works which have been done on welding of low carbon steel. This work, presents some heat treatments were used to alter the microstructure of base metal (BM), heat affected zone (HAZ) and weld metal (WM) in the welded pipe steel of grade API X70.

INFLUENCE OF HEAT TREATMENTS ON THE MICROSTRUCTURE

This investigation is a contribution to some scientific works which have been done on welding of low carbon steel. This work, presents some heat treatments were used to alter the microstructure of base metal (BM), heat affected zone (HAZ) and weld metal (WM) in the welded pipe steel of grade API X70. Investigations on Reformed Austenite in the Microstructure Nov 26, 2020 · This work investigates the reformed austenite in the super duplex stainless /pipeline steel dissimilar weld, fabricated using gas tungsten arc welding

Investigations on Reformed Austenite in the Microstructure

Nov 26, 2020 · This work investigates the reformed austenite in the super duplex stainless /pipeline steel dissimilar weld, fabricated using gas tungsten arc welding MICROSTRUCTURE AND MECHANICAL PROPERTIES OF In this work, the optical microscope, Electron backscattered diffraction (EBSD), X-ray diffraction and Transmission electron microscope (TEM) were used to investigate the microstructure of the X70 pipeline steel base metal, the weld bead and heat affected zone.

Mechanical and Metallurgical Properties of Grade X70 Steel

Sep 26, 2020 · The microstructure of thermomechanically processed X70 pipeline steel primarily consisted of acicular ferrite (AF) together with small fraction of polygonal ferrite(PF), degenerated pearlite Mechanical property-microstructure relationships of an X70 Nov 04, 2020 · For the X70 steel, at temperatures (225400 °C) just above the upper bound of the DSA regime, strain assisted bainitic tempering (stages one and two) produced properties which differed from those exhibited by the control X52 steel and resulted from the effects of dynamic tempering (i.e. strain-assisted tempering during deformation) to modify the bainitic microstructure.

Microstructure Evolution of Grade X100 Pipeline under

Granular bainite microstructure transformation pictures before and after plastic deformation are shown in Figure 4. that the ductility of the grade X100 pipeline possessed lots of tiny crystal grain is worse than that lower level pipeline steel, such as X70 or X80. Therefore, X100 pipeline is not good for laying through complicated regions. Microstructure and Mechanical Properties of X70 Pipeline Anti-H2S X70 pipeline steel was developed. The microstructure of X70 pipeline steel was studied by the analysis of OM, SEM and TEM. The precipitation behavior was discussed. The comprehensive mechanical properties, HIC and SCC performance were systematically studied. The results indicated that the microstructure of the experimental steel was mainly acicular ferrite and granular bainite.

Microstructure and Properties of Low Manganese API X70

The microstructure of thermomechanically processed X70 pipeline steel primarily consisted of acicular ferrite (AF) together with small fraction of polygonal ferrite (PF), degenerated pearlite (DP) and martensite/austenite (M/A) constituent. The AF predominant microstructure is fine, homogeneous and free of band structure of hard phase. Microstructure and texture evolution in warm rolled API 5L Jan 01, 2019 · In this work, all experiments were carried out on API 5L X70 pipeline steel. The chemical composition of the X70 steel is shown in Table 1.The SoAl in Table 1 represents soluble aluminum. As shown in the table, the total Al is 0.044 wt%, from which only 0.036 wt% is dissolved in the metal (soluble Al) while the rest is tied up by oxides/inclusions.

Microstructure characteristics and mechanical properties

Apr 12, 2012 · The relation between microstructure characteristics and mechanical properties of X80 pipeline steels was investigated using optical microscopy, scanning electron microscopy, etc. It is shown that the structure consists of polygonal ferrite (PF), quasi-polygonal ferrite (QPF), acicular ferrite (AF), and granular bainitic ferrite (GF). With increasing volume fraction of M-A islands (below 3% Microstructure transformation of X70 pipeline steel Fig. 4 TEM images a, b and EDS spectrum c of insoluble TiN particles in X70 pipeline steel Microstructure transformation of X70 pipeline steel welding heat-affected zone 497 Jan 2005 Xu Xl

Microstructure, texture evolution and mechanical

Aug 04, 2017 · Abstract The evolution of microstructure, texture and mechanical properties of API X70 pipeline steel after different thermomechanical treatments has been studied using a combination of X-ray diffraction and electron backscatter diffraction (EBSD). Microstructure, texture evolution and mechanical The evolution of microstructure, texture and mechanical properties of API X70 pipeline steel after different thermomechanical treatments has been studied using a combination of X-ray diffraction and electron backscatter diffraction (EBSD). Our investigations revealed that different microstructure consisting of polygonal ferrite, bainite, coarse

Role of Microstructure in Susceptibility of X70 Pipeline

In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions:normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content. Role of Microstructure in Susceptibility of X70 Pipeline In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions:normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content.

Severstal Supplies X70 Coils to Alfapipe in Algeria

Nov 26, 2020 · Russian steel giant PJSC Severstal has resumed supplies to Alfapipe, a spiral welded pipe manufacturer in Algeria. For the client, the metallurgists produced 26 thousand tonnes of X70 strip steel Study of Pipeline Steels with Acicular Ferrite 2015; 18(1) Study of Pipeline Steels with Acicular Ferrite Microstructure and Ferrite-bainite Dual-phase Microstructure 39 different. Dual-phase microstructure in steel 2 and steel 3 will decrease the yield strength by approximately 100 MPa, thereby leading to the decrease of yield ratio from 0.85 in

Study of Pipeline Steels with Acicular Ferrite

For X70 pipeline steel, an acicular ferritic microstructure is an optimal microstructure because of its excellent combination of strength and toughness. The 12. Petrov R, Kestens L and Houbaert Y. Characterization of the microstructure and transformation behaviour of strained and nonstrained austenite in NbV-alloyed CMn steel. Study of Pipeline Steels with Acicular Ferrite For X70 pipeline steel, an acicular ferritic microstructure is an optimal microstructure because of its excellent combination of strength and toughness. The 12. Petrov R, Kestens L and Houbaert Y. Characterization of the microstructure and transformation behaviour of strained and nonstrained austenite in NbV-alloyed CMn steel.

The Influence of Centerline Segregation on the Mechanical

The Influence of Centerline Segregation on the Mechanical Performance and Microstructure of X70 Pipeline Steel. Fujian Guo. Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, P. R. China. Search for more papers by this author. The Influence of Centerline Segregation on the Mechanical The Influence of Centerline Segregation on the Mechanical Performance and Microstructure of X70 Pipeline Steel. Fujian Guo. Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, P. R. China. Search for more papers by this author.

[JCSE])

Keywords:microstructure, low carbon steel, pipeline steel, corrosion rate, corrosion products, protective properties, alkaline soil. Abstract:In this work, we tried to examine the effect of microstructure of Low Carbon pipeline steels on their behavior to corrosion when they are buried in alkaline soil. link.springerThe development of inhomogeneity in the microstructure, texture, and mechanical property in hot-rolled (API) 5L X70 pipeline steel after rough and finish thermomechanical control processing has been investigated by experimental measurements. Our investigations revealed that the rough rolling stage produced mostly large and coarse ferrite grains across the thickness, while the finish rolling

Microstructure transformation of X70 pipeline steel

Jul 31, 2014 · Abstract. The continuous cooling transformation curve of heat-affected zone (HAZ) of X70 pipeline steel was measured by Gleeble-3500 thermal mechanical simulator, optical microscope (OM) and hardness analysis. The microstructure transformation rule at different cooling rates and solution behaviors of microalloy carbonitride during heating process of simulated specimens were investigated.

Leave a Comment