scholarly journals Corrosion Behavior of Welded Joints of X70 Pipeline Steel Produced by High-frequency Welding

2019 ◽  
pp. 1-9
Author(s):  
Anatolii Klymenko ◽  
Svetlana Kovalenko ◽  
Vitalii Kuzmenko ◽  
Yurii Kovalenko
Keyword(s):  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Kinetic Parameters ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
High Frequency ◽  
Welded Joint ◽  
Pipeline Steel

Corrosion behavior of welded joints of steel pipe category X70 produced by high-frequency welding, in different conditions, in which it is possible to initiate stress-corrosion cracking, hydrogen or sulfide cracking, was investigated. According to the results of electrochemical researches, the kinetic parameters of the cathode and anode processes on the surface of the welded joint of pipe in the investigated solutions are determined. Corrosion resistance of the welded joint HFW-pipe is similar to corrosion resistance of the base metal.

scholarly journals Stress corrosion resistance of welded joints of low-alloy pipe steel produced by high frequency welding

2020 ◽  
Vol 61 (4) ◽  
pp. 328-338
Author(s):  
Lyudmila Nyrkova ◽  
Sergiy Prokopchuk ◽  
Svetlana Osadchuk ◽  
Anatoliy Rybakov ◽  
Larisa Goncharenko
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Stress Corrosion ◽  
Base Metal ◽  
Cathodic Protection ◽  
Welded Joints ◽  
High Frequency ◽  
Welded Joint ◽  
Stress Corrosion Resistance

The paper presents the results of stress corrosion resistance studies of welded joints of low-alloy steel 17G1SU, obtained by high-frequency welding (HFW). The potentiometry method has established that the welded joint in the state after welding and after linear heat treatment is resistant to corrosion, because the potential difference between the weld and the base metal does not exceed (30-50) mV. According to the results of accelerated corrosion-mechanical tests in 3% NaCl under conditions of constant load under different stress, it was found that the rate of uniform corrosion of both types of welded joints is almost the same as the base metal. Slightly higher corrosion rate of the welded junction after linear heat treatment correlates with the electrochemical data. In general, the welded joint, made according to the factory technology, has resistance to corrosion and mechanical destruction in a solution of 3% NaCl at the level of the base metal, in the absence of weld defects. In the range of protective polarization potentials normalized by the standard of Ukraine, the ratio of the cathodic protection current to the diffusion current limit for the base metal and for the weld metal practically does not differ. It can be expected that under the conditions of cathodic protection, the predominant local flooding of the weld metal or the parent metal is not expected.

Investigation of mechanical and corrosion behavior of laser hybrid weld joint of 2205 duplex stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanbo Zheng ◽  
Cheng Zhang ◽  
Xiao Yong Wang ◽  
Jie Gu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Welded Joints ◽  
Two Phase ◽  
Content Type ◽  
2205 Duplex Stainless Steel ◽  
Laser Hybrid

Purpose Duplex stainless steel is composed of equal amounts of austenite and ferrite, which has excellent corrosion resistance and strength. However, after the metal was welded, the ratio of austenite and ferrite in the joint is unbalanced, and secondary phase precipitates are produced, which is also an important cause of pitting corrosion in the joint. Design/methodology/approach This paper aims to study the mechanical and corrosion behavior of welded joints, by adjusting the welding parameters of laser hybrid welding, dual heat sources are used to weld 2205 duplex stainless steel. The two-phase content of different parts of the welded joint is measured to study the influence of the ratio of the two-phase on the mechanical and corrosion properties of the joint. Findings The ratio of austenite and ferrite in different welded joints has an obvious difference, and from top to bottom, the austenite content decreased gradually, and the ferrite content increased gradually. The harmful phases are precipitated in the middle and lower part of the joint. The strength of welded joints is slightly lower than that of base metal. At the same time, the fracture analysis shows that some ferrite phases are affected by the precipitate in the grain and produce quasi-cleavage fracture. The corrosion results show that the corrosion resistance of the welded joints is lower than that of the base metal, and the concentration of chloride ions affects the corrosion resistance. Originality/value In this paper, the authors use the influence of different welding processes on the two-phase ratio of the joint to further study the influence of the microstructure on the corrosion resistance and mechanical properties of the weld.

Probing the stress corrosion cracking resistance of laser beam welded AISI 316LN austenitic stainless steel

2020 ◽  
pp. 095440622096563
Author(s):  
R Rajasekaran ◽  
AK Lakshminarayanan
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Laser Beam ◽  
Stress Corrosion ◽  
Base Metal ◽  
Stress Corrosion Cracking ◽  
Welded Joint ◽  
Corrosion Cracking ◽  
Time To Failure

The stress corrosion cracking (SCC) resistance of the laser beam welded (LBW) AISI 316LN austenitic stainless steel (SS) was assessed and compared to the base metal (BM). The weld joint was produced using a 2.5 kW laser power source at 1500 mm/min welding speed. Microstructural characterization of the base metal and weld joint were done by the following techniques: (i) Optical Microscopy (OM), (ii) Scanning Electron Microscopy (SEM) and (iii) Transmission Electron Microscopy (TEM). The primary mechanical properties such as strength, toughness and hardness of the welded joint were evaluated and compared with the base metal. Stress Corrosion Cracking (SCC) assessment was done in boiling 45 wt% MgCl2 solution at constant load condition as per American Society for Testing and Materials (ASTM) standard G36-94. From the SCC experiment data, steady-state elongation rate ([Formula: see text]), transition time ([Formula: see text]) and time to failure ([Formula: see text]) were found and generalized equations to predict the time to failure of the base metal and LBW joint were successfully derived. The passive film rupture mechanism majorly influenced the SCC failure for 316LN and welded joint. The formation of the discontinuous δ-ferrite network, residual stress and nitrogen pore nucleation at the fusion zone of the LBW joint deteriorated the SCC resistance. The metallographic and fractographic studies revealed brittle transgranular SCC failure of the base metal as well as the LBW joint in all the stress conditions.

The Corrosion Behavior of Welded Line Pipes in Wet H2S Environment

2002 ◽  
Author(s):  
Yaorong Feng ◽  
Chunyong Huo ◽  
Feng Yan
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Applied Stress ◽  
Corrosion Behavior ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Steel Pipes ◽  
H2s Corrosion ◽  
Hydrogen Induced Cracking

The corrosion behavior of over-bending and under-bending formed Spiral Submerged Arc Welded (SSAW) steel pipes in NACE solution has been investigated by use of the self-designed full-scale corrosion test unit. It indicates that the H2S damage of welded pipes characteristics Blister and Stress Corrosion Cracking (SCC). The blister number, diameter, and crack number is increasing as the increasing of applied stress. The residual stress of welded pipes has a large effect on the H2S corrosion resistance, the tensile residual stress has a detrimental effect, and while the compression residual stress is beneficial to H2S corrosion resistance. The damage mechanism of the welded pipes in H2S containing solution under the presence of applied stress and residual stress has not only Hydrogen Induced Cracking (HIC), but also Stress Corrosion Cracking, and the applied stress and residual stress promote not only Stress Corrosion Cracking, but also Hydrogen Induced Cracking. The test results reveal that improving pipe’s weld surface quality, lowering tensile residual stress, and also control the operating stress are the key measures for controlling the wet H2S corrosion of welded steel pipes. Suggestions for selection of line pipes in different service conditions have been made.

Microstructure and Properties of Lean Duplex Stainless Steel UNS S32101 Welded Joint by Hot Wire TIG Welding

2020 ◽  
Vol 993 ◽  
pp. 466-473
Author(s):  
Liang Liang Bao ◽  
Yong Wang ◽  
Tao Han
Keyword(s):  
Corrosion Resistance ◽  
Base Metal ◽  
Pitting Corrosion ◽  
Welded Joints ◽  
Welded Joint ◽  
Tig Welding ◽  
Hot Wire ◽  
Average Value ◽  
Pitting Corrosion Resistance ◽  
Temperature Heat

Lean duplex stainless steel UNS S32101 was welded by hot wire TIG welding and traditional TIG welding, and nice formed welds with no visible defects were obtained. Metallographic microstructure, phase ratio, mechanical properties and pitting corrosion resistance property of the welded joints were tested. Microstructure analysis showed that the hot wire TIG and traditional TIG welded joints had similar microstructures. The welded metal was composed of ferrite, grain boundary austenite (GBA), Widmanstatten austenite (WA), intragranular austenite (IGA). The high temperature heat affected zone (HTHAZ) consisted of ferrite, GBA and IGA. The low temperature heat affected zone (LTHAZ) had semblable microstructures with base metal. The phase ratio of welded joints was measured by manual point count method. The ferrite/austenite ratio of hot wire TIG welded metal was close to 1:1. The welded joints of hot wire TIG and traditional TIG had same hardness distribution. The hardness of hot wire TIG with an average value of 291 HV10 was a little higher than that of traditional TIG with an average value of 280 HV10. Charpy impact test at -40°C showed that the impact values of hot wire TIG and traditional TIG welded joints meet the standard requirements. The results of chemical weight loss method showed that the corrosion rate of hot wire TIG welded joint was less than 10 mdd. Potentiodynamic polarization method results showed that the pitting corrosion resistance of hot wire TIG welded joints was slightly lower than that of base metal. Solid solution treatment significantly increased the pitting corrosion resistance of welded joints and base metal. The hot wire TIG and traditional TIG had similar microstructure and properties under the same arc power, however the welding speed of hot wire TIG was 1.5 times higher than that of traditional TIG and the welding efficiency was greatly improved.

scholarly journals Corrosion Behavior of Welded Joint of Q690 with CMT Twin

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Peng Liu ◽  
Shanguo Han ◽  
Yaoyong Yi ◽  
Cuixia Yan
Keyword(s):  
Corrosion Resistance ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Welded Joint ◽  
Weld Zone ◽  
Quantitative Information ◽  
Low Alloy Steel ◽  
Nacl Solution ◽  
Corrosion Rates ◽  
Electrode Technique

Low alloy steel of Q690 was welded with the method of CMT Twin. The corrosion behavior of welded joint had been investigated using scanning vibrating electrode technique (SVET) in 3.5% NaCl solution. The research results showed that the appearance of the troostite increased the hardness of the heat affected zone. Furthermore, the corrosion products of different microstructure were identical, and the white products (Fe(OH)2) of welded joint turned into products of rufous (Fe(OH)3). The quantitative information provided by SVET was discussed, and the corrosion degree was measured by some parameters. In comparison with other areas, the corrosion rates of the overheated zone and the base metal were higher. Then, the corrosion resistance of the weld zone with CMT Twin was greatly improved, when compared with that of the base metal. Therefore, Ni has significant influence on corrosion resistance of weld zone. In summary, it can be discovered that the corrosion rates of various zones were related to the welding heat input.

Effect of Laser Shock Processing on Sulfide Stress Corrosion Cracking of X70 Pipeline Steel Welded Joint

2010 ◽  
Vol 44-47 ◽  
pp. 451-455
Author(s):  
Jun Feng Pei ◽  
Jun Ning Liu ◽  
Wei Ying He
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joint ◽  
Pipeline Steel ◽  
Corrosion Cracking ◽  
Laser Shock Processing ◽  
X70 Pipeline Steel ◽  
Sulfide Stress ◽  
Shock Processing ◽  
Sulfide Stress Corrosion Cracking

Laser shock processing (LSP) is a new technique for metal surface strengthening by which residual compressive stress in the superficial layer can be induced to greatly improve the stress corrosion resistance property. The effect of LSP on sulfide stress corrosion cracking (SSCC) of X70 pipeline steel welded joint has been studied in this paper. A convergent lens is used to deliver 20 J, 20 ns laser pulses by a Q switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 3 mm onto samples. The power density of laser at the surface of the sample was about 5 GW/cm2. The surface residual stress level after LSP is much higher than before. SSCC behavior of X70 pipeline steel welded joint was investigated using slow strain rate testing (SSRT) in H2S solution. Morphology of X70 pipeline steel fracture surface was observed by scanning electron microscope (SEM). It has been demonstrated that LSP is an effective surface treatment technique to improve the stress corrosion cracking (SCC) resistance properties of X70 pipeline steel welded joints.

AMBRONZE 413

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Electrical Contact ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Tin Bronze

Abstract AMBRONZE 413 is a copper-tin bronze recommended for plater's plates and electrical contact springs. It is relatively immune to stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-201. Producer or source: Anaconda American Brass Company.

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