Residual Stress Assessment and its Effect on SCC of Pipelines Steel in Acidic Soil Environment

2014 ◽  
Vol 1616 ◽  
Author(s):  
A. Contreras ◽  
L.M. Quej-Ake ◽  
R. Galvan-Martinez ◽  
O. Vega
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Soil Solution ◽  
Pipeline Steel ◽  
Acidic Soil ◽  
Soil Environment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Welding Joints ◽  
Internal Side

ABSTRACTEffect of residual stresses of multiple welding repairs on API 5L X52 pipeline steel on stress corrosion cracking (SCC) in a simulated acidic soil solution was studied. Four conditions of repairs of the girth weld were evaluated. The residual stresses were measured through X-ray diffraction (XRD) on the internal side of the pipe in longitudinal and circumferential direction. The circumferential and longitudinal residual stresses values are compressive on the inner surface of the welding joints. The highest residual stresses were measured in the hoop direction reaching values of about 98% of the yielding strength (360 MPa). It was observed that its magnitude increases as move away from weld center line. The effect of residuals stresses in the SCC susceptibility of X52 pipeline steel was evaluated through slow strain rate tests (SSRT) in a simulated acidic soil solution. Relation between mechanical properties obtained from SSRT and residual stresses on the SCC susceptibility was analyzed. Results of SCC index taking account the ratios obtained from the mechanical properties of the welding joints evaluate, showed good SCC resistance in acidic soil solution at low pH. Scanning electron microscopy (SEM) observations showed that the region with high residual stresses prior to generate cracks in the steel due to the combination of soil solution and the strain exerted, should favor pitting formation and not cracking.

The Role of Residual Stresses in Circumferential Welding Repairs of Pipelines in SCC Susceptibility

2014 ◽  
Vol 793 ◽  
pp. 159-168
Author(s):  
Antonio Contreras-Cuevas ◽  
J. Alamilla-López ◽  
Ricardo Galván-Martínez ◽  
O. Vega-Becerra
Keyword(s):  
Residual Stresses ◽  
Pipeline Steel ◽  
Longitudinal Direction ◽  
X Ray Diffraction ◽  
Shielded Metal Arc Welding ◽  
High Ph ◽  
Metal Arc Welding ◽  
Welding Joints ◽  
Internal Side

The main objective of the present study is to measure the residual stresses in the circumferential welding joints of X52 pipeline steel with multiple welding repairs, and then relate these residual stresses to study the influence on the high pH stress corrosion cracking (SCC) susceptibility. Four conditions of shielded metal arc welding (SMAW) repairs of the girth weld were evaluated. The residual stresses were measured through X-ray diffraction (XRD) on the internal side of the pipe in longitudinal and circumferential direction. Residual stresses in the circumferential and longitudinal direction reach values of about 98 and 74% of the yielding strength (360 MPa) respectively. The effect of residuals stresses in the high pH-SCC susceptibility of X52 pipeline steel was evaluated through slow strain rate tests (SSRT) in a simulated soil solution. Relation between SCC index and residual stresses on the SCC susceptibility was analyzed. Results of SCC index taking account the ratios obtained from the mechanical properties of the welding joints evaluate (containing different levels of residual stresses) showed good SCC resistance. It was observed that increasing the magnitude of residual stresses, the SCC susceptibility increases. For all the SSRT specimens the failure occurs in the base metal and heat affected zone (HAZ) interface.

scholarly journals Effect of Sulfate-Reducing Bacteria (SRB) on the Corrosion of Buried Pipe Steel in Acidic Soil Solution

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Lijuan Chen ◽  
Bo Wei ◽  
Xianghong Xu
Keyword(s):  
Soil Solution ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Electrochemical Techniques ◽  
Sulfate Reducing Bacteria ◽  
Acidic Soil ◽  
Microbiologically Influenced Corrosion ◽  
Soil Environment ◽  
Sulfate Reducing ◽  
Reducing Bacteria

The influence of sulfate-reducing bacteria (SRB) on the corrosion behaviors of X80 pipeline steel was investigated in a soil environment by electrochemical techniques and surface analysis. It was found that SRB grew well in the acidic soil environment and further attached to the coupon surface, resulting in microbiologically influenced corrosion (MIC) of the steel. The corrosion process of X80 steel was significantly affected by the SRB biofilm on the steel surface. Steel corrosion was inhibited by the highly bioactive SRB biofilm at the early stage of the experiment, while SRB can accelerate the corrosion of steel at the later stage of the experiment. The steel surface suffered severe pitting corrosion in the SRB-containing soil solution.

Remediation Effects of Steel Slag and Fly Ash on Heavy Metal Contaminated Acidic Soil

2013 ◽  
Vol 647 ◽  
pp. 726-731 ◽  
Author(s):  
Hai Hong Gu ◽  
Fu Ping Li ◽  
Qiang Yu ◽  
Yong Li Xu ◽  
Jun Ying Zhang
Keyword(s):  
Heavy Metal ◽  
Fly Ash ◽  
Steel Slag ◽  
Acidic Soil ◽  
Soil Environment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Potential Strategy ◽  
By Products

The remediation effects and mechanisms of the by-products of industry, fly ash and steel slag, on heavy metal contaminated acidic soil were investigated in this study. Fly ash was added at 0, 10, 20, 40, 60 and 80 g kg-1dry weight soil, and steel slag was added at 0, 1, 3, 5, 6 and 8 g kg-1dry weight soil, respectively. The results indicated that the application of fly ash and steel slag significantly increased soil pH values, and the increments improved with the increasing amendment dosages. The treatments of fly ash added at 20-40 g•kg-1and steel slag at 3-6 g•kg-1had the pH values within 5.5-7.0, and theSuperscript textneutral and weakly acidic soil environment was suitable for plant growth. The addition of amendments substantially decreased the avalibility of heavy metals, and the higher amendment dosages resulted in the lower CaCl2extractable heavy metal concentrations. X-ray diffraction analysis indicated that the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. These results demonstrated that the application of fly ash and steel slag might be a potential strategy to remediate heavy metal contaminated acidic soil.

scholarly journals Tempering Influence on Residual Stresses and Mechanical Properties of AISI 4340 Steel

2021 ◽  
Author(s):  
Marcel Souza ◽  
Luana Ferreira Serrão ◽  
Juan Manuel Pardal ◽  
Sérgio Souto Maior Tavares ◽  
Maria Cindra Fonseca
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
X Ray Diffraction ◽  
Tempered Martensite ◽  
Tempering Temperature ◽  
Aisi 4340 Steel ◽  
X Ray ◽  
4340 Steel ◽  
Compressive Residual Stresses ◽  
Aisi 4340

Abstract The present work evaluated the tempering temperature influence on microstructure, mechanical properties and residual stresses of AISI 4340 steel. The residual stresses were measured by X‑ray diffraction (XRD) by the sin²ψ method and compared to magnetic Barkhausen noise (MBN). The residual stresses exhibited high tensile values after quenching, but a small relief was observed in tempering treatments at 300°C and 400°C, which also presented a hardness decrease compared to the as‑quenched condition. XRD and MBN analyses indicated that residual stresses became compressive in tempering performed between 500°C and 650°C. Therefore, compressive residual stresses combined with appropriate hardness and toughness values (35 HRC and 33 J) obtained from 500°C tempering temperature can be used to improve the mechanical properties of AISI 4340 steel components. Additionally, a mathematical model was established to estimate the tempered martensite hardness for different tempering temperature conditions. This model showed high accuracy (R2=0.99) for a holding time of 90 minutes.

Comparative Study of Residual Stresses in Pipeline Steel by X-Ray Diffraction and Ultrasonic Technique

2020 ◽  
Author(s):  
Maria Cindra Fonseca ◽  
Bruna Machado ◽  
Mauricio Motta ◽  
Joao Marcos Alcoforado Rebello
Keyword(s):  
Residual Stresses ◽  
Comparative Study ◽  
Pipeline Steel ◽  
Ultrasonic Technique ◽  
X Ray Diffraction ◽  
X Ray

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

scholarly journals The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Resistance ◽  
Mechanical Analysis ◽  
Northeastern Brazil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Agents ◽  
Natural Stones

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

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