scholarly journals Microstructure, roughness, and corrosion resistance of X5CrNi18-10 austenite stainless steel welded joint

2021 ◽  
pp. 7-7
Author(s):  
Bojana Radojkovic ◽  
Bore Jegdic ◽  
Jovanka Kovacina ◽  
Sanja Stevanovic ◽  
Dunja Marunkic
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Pitting Corrosion ◽  
Welded Joint ◽  
Electrochemical Testing ◽  
Limit Value ◽  
Before And After ◽  
Degree Of Sensitization

The influence of the microstructure of the X5CrNi18-10 stainless steel welded joint on its resistance to general, pitting, and intergranular corrosion was analysed. The structure of weld metal, heat affected zone (HAZ) and base metal before and after electrochemical testing was analysed using SEM/EDS. The influence of the roughness level of the welded joint on its resistance to the mentioned types of corrosion was examined as well. Although the degree of sensitization of HAZ was significantly lower than the limit value, HAZ showed a noticeably greater tendency to general and pitting corrosion than weld metal and base metal. Polishing has been shown to significantly improve the corrosion resistance of HAZ than in the case of other parts of the welded joint.

scholarly journals Testing of intergranular and pitting corrosion in sensitized welded joints of austenitic stainless steel

10.30544/274 ◽  
2017 ◽  
Vol 23 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Bore V. Jegdic ◽  
Biljana Bobić ◽  
Milica Bošnjakov ◽  
Behar Alić
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Pitting Corrosion ◽  
Heat Affected Zone ◽  
Intergranular Corrosion ◽  
Chromium Concentration ◽  
Pitting Corrosion Resistance

Pitting corrosion resistance and intergranular corrosion of the austenitic stainless steel X5Cr Ni18-10 were tested on the base metal, heat affected zone and weld metal. Testing of pitting corrosion was performed by the potentiodynamic polarization method, while testing of intergranular corrosion was performed by the method of electrochemical potentiokinetic reactivation with double loop. The base metal was completely resistant to intergranular corrosion, while the heat affected zone showed a slight susceptibility to intergranular corrosion. Indicators of pitting corrosion resistance for the weld metal and the base metal were very similar, but their values are significantly higher than the values for the heat affected zone. This was caused by reduction of the chromium concentration in the grain boundary areas in the heat affected zone, even though the carbon content in the examined stainless steel is low (0.04 wt. % C).

Semiconductor properties of passive film and corrosion resistance of 2205 duplex stainless steel joint welded by laser hybrid welding

2019 ◽  
Vol 66 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Guo Yi ◽  
Junhua Xu ◽  
Chuanbo Zheng
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Passive Film ◽  
Pitting Corrosion ◽  
Welded Joint ◽  
Hybrid Welding ◽  
Content Type ◽  
Laser Hybrid Welding ◽  
The Difference ◽  
Laser Hybrid

Purpose There are obvious differences in corrosion resistance of different 2205 welding joints with different ratios of austenite and ferrite, from the top to the bottom, the austenite content decreased gradually while the ferrite increased. In each region of welded joint, the pitting resistance number of ferrite is higher than that of austenite; pitting corrosion is more likely to occur in austenite phase first on the top region of the weld and in the secondary phase precipitates on the other regions of the weld. The fluctuation of the ratio of austenite and ferrite has a great influence on performance of passive film in 3.5 per cent NaCl solution. Design/methodology/approach To study the corrosion behavior of welded joint, the samples were obtained by laser hybrid welding. Pitting corrosion was studied in different area of welded joint. The Mott–Schottky curves of welded joints were measured to study the passive film on the different welded joint area. Findings Due to the difference of heat input and the limit of filler depth of the wire, the microstructure of duplex stainless steel laser welding joint has obvious difference in the thickness direction. In addition, there will be harmful secondary phase (such as chromium nitride and σphase) precipitates in the lower part of the joint. For the welded joint, the corrosion resistance decreases with the increase in the difference of the microstructure. Pitting corrosion usually takes the two phases as the nucleation point and grows up. The surface of 2205 duplex stainless steel laser hybrid welding joint cannot form a complete passive film in 3.5 per cent NaCl solution, and the more the ratios of austenite and ferrite deviate from equilibrium position (50:50), the worse the performance of passive film is. Originality/value In this paper, the authors attempt to establish the correlation between the semiconductor electronic properties of passive film and the difference of microstructures and the component in a joint welded by laser hybrid welding. The effect of passive film on the corrosion resistance of the weld was further investigated.

Research on Microstructure and Properties of Welded Joint of 2205 Steel with FCAW

2011 ◽  
Vol 391-392 ◽  
pp. 763-767
Author(s):  
Li Yang ◽  
Na Zhang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
High Strength ◽  
Two Phase ◽  
Flux Cored Arc Welding ◽  
Mechanical Properties And Corrosion

On the basis of the analysis of composition, microstructure, properties and weldability of 2205 duplex stainless steel, the flux cored arc welding (FCAW) process is made. Then the microstructure, mechanical properties and corrosion resistance of welded joint were analyzed. The results shows using FCAW process, in order to obtain high strength, perfect impact toughness and overall and partial resistance to stress corrosion in welded joint, the Ni content of duplex stainless steel welding material should be 2% to 4% higher than that of base metal, multi-layer and multi-channel welding is adopted with the strict control of energy input less than or equal to 0.926KJ/mm, layer temperature is less than 120 °C, thus the appropriate proportion of two-phase structure in the welded joint can be got. Using a reasonable welding procedure, the microstructure in weld beam is austenite (A) + ferrite (F), and in heat affected zone is ferrite (F) + austenite (A) + a small amount of third phase, the content of austenite in weld beam and heat affected zone is higher than that of the base metal. Tensile strength of the welded joint is up to 854.5MPa and the fracture occurs in the base metal and the heat affected zone. The welded joint has high strength, good plasticity, toughness and corrosion resistance.

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 The Pitting Corrosion Behavior of the Austenitic Stainless Steel 308L-316L Welded Joint

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1258
Author(s):  
Jinshan He ◽  
Shiguang Xu ◽  
Wenxin Ti ◽  
Yaolei Han ◽  
Jinna Mei ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Statistical Analysis ◽  
Austenitic Stainless Steel ◽  
Passive Film ◽  
Pitting Corrosion ◽  
Welded Joint ◽  
Weld Zone ◽  
Electrochemical Tests ◽  
Pitting Corrosion Resistance

The pitting corrosion resistance of the austenitic stainless steel 308L-316L welded joint was investigated by electrochemical tests. It is found that the weld zone was the most critical for pits to initiate in the welded joint due to relatively instable passive film with few Mo and inhomogeneous passive film induced by multiple (Mn, Al, and Si) oxides and continuous network of 13.94 vol.% δ ferrites. By statistical analysis, 53.8% pits initiated at (Mn, Al, and Si) oxides, 23.0% in austenite, and 23.2% at interface between ferrite and austenite. In addition, heat-affected zone was prone to have pitting corrosion compared with the base metal since residual strain was much higher in the region.

Effects of Post Weld Ageing Heat Treatments on the Microstructure of 17-4PH GTA Welded Joints

2011 ◽  
Vol 264-265 ◽  
pp. 1300-1305 ◽  
Author(s):  
Seyed Ali Asghar Akbari Mousavi ◽  
S.A. Hoseini Hosein Abad
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Weld Metal ◽  
Mechanical Strength ◽  
Base Metal ◽  
Precipitation Hardening ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Operational Parameters ◽  
Before And After

The mechanical and metallurgical properties of the 630 (17-4PH) precipitation hardening stainless steel is greatly influenced by the type of applied heat treatments cycles. In order to achieve the homogenous microstructure in the weld metal and eliminate the HAZ due to producing the weak mechanical strength, and producing similar microstructures and mechanical strength in both weld and base metal, the study was conducted to find an optimum pre and post heat treatments before and after welding. The 2.2mm thick and 48mm tube diameter made of 630 stainless steel were welded under various operational parameters. The samples were subjected to pre weld solution treatment and post weld aging heat treatment. To reveal the microstructures of the welds, the optical and scanning electron microscopy of the welds carried out. The study shows that the direct ageing treatment at 6200C after welding can give rise to the best heat treatment to produce, the uniformity in the grain size, mechanical strength and hardness, between the base metal and the weld metal.

scholarly journals Influence of Nb Content on Sensitization and Pitting Corrosion of Welded AISI 430 Ferritic Stainless Steel

2019 ◽  
Vol 24 ◽  
Author(s):  
Caroline Nazaré Gonçalves ◽  
Gabriel Mendes de Almeida Carvalho ◽  
Jordânio Samuel Siqueira ◽  
Reny Ângela Renzetti
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Ferritic Stainless Steel ◽  
Pitting Corrosion ◽  
Heat Affected Zone ◽  
Electrochemical Techniques ◽  
Welding Process ◽  
Pitting Potential ◽  
Degree Of Sensitization ◽  
Aisi 430

Abstract In this work, the effect of Nb addition on sensitization and pitting corrosion of welded AISI 430 ferritic stainless steel subjected to autogenous GTAW was investigated by microstructural characterization and electrochemical techniques. The three distinct regions of welding process, weld metal, heat affected zone and base metal of AISI 430 steel with and without Nb were evaluated. The degree of sensitization was measured by double loop electrochemical potentiodynamic reactivation and pitting corrosion was studied by potentiostatic polarization test. The microstructural analyses reported martensite network in the weld metal and heat affected zone of AISI 430 non stabilized. The electrochemical studies revealed that the highest degree of sensitization and the lowest pitting potential are in the weld metal of AISI 430 without Nb.

Effect of Sensitization Treatment on Corrosion Properties in Austenitic Stainless Steel 304

2016 ◽  
Vol 857 ◽  
pp. 232-236 ◽  
Author(s):  
Chung Seok Kim ◽  
Seung Jae Moon ◽  
Won Sik Kong
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Intergranular Corrosion ◽  
Solution Treatment ◽  
Corrosion Properties ◽  
Before And After ◽  
Degree Of Sensitization ◽  
Electrochemical Potentiokinetic Reactivation ◽  
Materials Failure ◽  
Austenitic Stainless Steel 304

Chromium depletion in AISI304 stainless steel can lead to intergranular corrosion due to temperature conditions and degree of deformation, and consequently to materials failure. The aim of this work is to study the effect of sensitization treatment on the corrosion resistance in AISI304 stainless steel after solution heat treatment at 1,000°C. Sensitization treatments were carried out at 670°C for 1 h, 2h, 5h and 10h in the electrical furnace. The intergranular corrosion resistance of the sensitized specimens was evaluated by double loop electrochemical potentiokinetic reactivation test. The microstructure of the specimens before and after the corrosion tests was observed through optical and scanning electron microscope. Solution treatment shows the dual structure, however, aging for 5 hours depicts the ditch structure. The ratio of current density increased as a function of aging time resulted in increase in the degree of sensitization.

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