Corrosion Resistance Evaluation of a Stainless-Steel Brazed Joint in HCl Solution

2021 ◽  
Vol 1016 ◽  
pp. 997-1002
Author(s):  
Hikaru Nagata ◽  
Masa Ono ◽  
Yasuyuki Miyazawa ◽  
Yuji Hayashi ◽  
Yoshio Bizen

To clarify the effect of the acid solution type on corrosion resistance, the corrosion behavior of stainless steel brazed joints in HCl aqueous solution was evaluated through electrochemical measurements. Anodic polarization curves of a ferritic stainless-steel base metal, Ni-based brazing filler metals, and a brazed joint were recorded. In addition, in situ observations were conducted to observe the corrosion behavior of each structure of the brazed joint. Corrosion potentials of the brazing filler metal were lower than that of the base metal. In situ observations of the brazed joint revealed the order of corrosion in aqueous hydrochloric acid. According to the electrochemical measurements, under an actual corrosive environment, the brazing filler metal can function as an anode and selectively corrode. In addition, the anodic polarization curve of the brazed joint showed values between those of the polarization curves of the brazing filler metal and the base metal, indicating that the corrosion resistance could be electrochemically evaluated in HCl aqueous solution.

2021 ◽  
Vol 1016 ◽  
pp. 522-527
Author(s):  
Anna Hashimoto ◽  
Shu Bin Liu ◽  
Ikuo Shohji ◽  
Tatsuya Kobayashi ◽  
Junichiro Hirohashi ◽  
...  

Electrodeposited Ni-11 mass%P alloy plating film was fabricated on the surface of stainless steel SUS304 to conduct brazing of SUS304 plates for a heat exchanger. Brazing of SUS304 plates with electrodeposited Ni-11P layers was carried out using a hydrogen reducing furnace. The microstructure and joint strength of the brazed joint were also investigated. From the result of the microstructural observation of the cross section of the joint, it was found that the brazing filler metal is homogeneously distributed without defects such as voids between the SUS304 plates. The results of electrochemical measurements showed that the P-concentrated phase in the Ni-11P alloy is preferentially dissolved in NaCl aqueous solution.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanbo Zheng ◽  
Cheng Zhang ◽  
Xiao Yong Wang ◽  
Jie Gu

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.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1114-1119
Author(s):  
Sung Yul Lee ◽  
Kyung Man Moon ◽  
Jong Pil Won ◽  
Jae Hyun Jeong ◽  
Tae Sil Baek

Recently, wear and corrosion of the engine parts surrounded with combustion chamber is more serious compared to the other parts of the engine due to using of heavy oil of low quality. Therefore, an optimum repair welding for these parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal was welded with GTAW method in the forged steel which would be generally used with piston crown material. In this case, the mechanical and corrosion properties between weld metal zone (WM) welded to the groove which were artificially made in the base metal and deposited metal zone (DM) only welded by Inconel 625 filler metal on the surface of the base metal were investigated using electrochemical methods, such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% H2SO4 solution. The deposited metal zone exhibited a better corrosion resistance compared to the weld metal zone, furthermore, its corrosion potential was a nobler value rather than that of the weld metal zone. However, the hardness indicated more or less higher value in the weld metal zone. The corrosive products after measurement of anodic polarization curves was hardly observed both in the weld and deposited zones, while, the morphologies of the corroded surfaces exhibited general and pitting corrosion in the weld and deposited metal zones respectively. The fine pearlite microstructure was a little observed in the weld metal zone, moreover, the microstructure of ferrite with elliptical pattern was significantly increased in the deposited metal zone. As a result, it is considered that the amount of Cr, Mo and Ni having a high corrosion resistance diffuse and migrate from the weld metal zone to the base metal zone, thus, the deposited metal zone indicated a better corrosion resistance than the weld metal zone because the amount of Cr, Mo and Ni were much involved in deposited metal zone compared to the weld metal zone.


Author(s):  
Changqing Ye ◽  
Weiguo Zhai ◽  
Guangyao Lu ◽  
Qingsong Liu ◽  
Liang Ni ◽  
...  

In this paper, shielded metal arc welding on the dissimilar joint between 2205 duplex stainless steel and composite bimetallic plates (304 L stainless steel/10CrNi3MoV steel) with a filler metal E2209 was performed. Furthermore, the microstructure, phase, mechanical properties and intergranular corrosion resistance of the joints were investigated and element distributions of the interfaces were characterized. The results show that austenite transformed to ferrite under the influence of welding thermal cycle, and then a large amount of ferrite appeared in heat affected zone (HAZ) of 2205 duplex stainless steel. Coarse bainite grains were formed in HAZ of the 10CrNi3MoV steel near the fusion line with high temperature welding thermal cycle. Fine granular bainite was also generated in HAZ of 10CrNi3MoV steel due to the relatively short exposure time to the active temperature of grain growth. Local peak temperature near the base 10CrNi3MoV steel was still high enough to recrystallize the 10CrNi3MoV steel to form partial-recrystallization HAZ due to phase change. The filler metal was compatible with the three kinds of base materials. The thickness of the elemental diffusion interfaces layers was about 100 µm. The maximum microhardness value was obtained in the HAZ of 2205 duplex stainless steel (287 ± 14 HV), and the minimum one appeared in HAZ of SS304L (213 ± 5 HV). The maximum tensile strength of the welded joint was about 670 ± 6 MPa, and the tensile specimens fractured in ductile at matrix of the composite bimetallic plates. The impact energy of the weld metal and HAZ of the 10CrNi3MoV steel tested at –20 °C were 274 ± 6 J and 308 ± 5 J, respectively. Moreover, the intergranular corrosion resistance of the weldment including 304 L stainless steel, weld metal, HAZs and 2205 duplex stainless steel was in good agreement with the functional design requirements of materials corrosion resistance.


CORROSION ◽  
10.5006/3759 ◽  
2021 ◽  
Author(s):  
Yanli Wang ◽  
Ping Wang ◽  
Changxuan Wang ◽  
Shenghua Zhang

A Cr2O3 diffusion barrier was in-situ formed between Ni coating and 316L through electroplating a Ni(NiO) transition layer firstly and then annealing at 900 °C for 8 h in Ar. The obtained Cr2O3 is dense, continuously grown and well-bonded with 316L. The diffusion and corrosion resistance of Ni coating with and without Cr2O3 diffusion barrier were investigated. No visible outer diffusion of elements was found during the heat treatment at 750 °C for 150 h and the Ni coating with a Cr2O3 diffusion barrier can provide a good protection for 316L in molten (Li,Na,K)F.


Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1042
Author(s):  
Panneer Selvam Kevin ◽  
Abhishek Tiwari ◽  
Saravanan Seman ◽  
Syed Ali Beer Mohamed ◽  
Rengaswamy Jayaganthan

Cr3C2–NiCr coatings have been used extensively to combat the erosion corrosion of hydro power turbine blades made of stainless steel. Cr3C2–NiCr coatings are also used in aqueous corrosive environments due to the high corrosion resistance rendered by the NiCr binder. In this investigation, both erosion and corrosion environments are introduced to cermet coating to study corrosion behavior using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The cermet coatings are useful for reducing the risk of deterioration of mechanical properties of hydro power turbines due to the continuous exposure to the erosive and corrosive action of the corrosive environment containing silt. It was observed that Cr3C2–NiCr coating offered a reasonable improvement in corrosion resistance when compared to bare substrate. The corrosion behavior of the coating was studied in a 150 mL solution of 0.1 M NaCl with 2 gms of quartz particles (0.2–0.8 mm) at various rotation speeds (3000, 4500, 6000 rpm) of the solution over a 1 h immersion using potentiodynamic polarization and EIS studies in a specifically designed experimental set-up for erosion corrosion. When compared to the bare stainless steel samples at 3000 rpm and 6000 rpm, the coating showed the highest improvement at 6.57 times and the least improvement at 3.79 times, respectively.


2020 ◽  
Vol 67 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Chuanbo Zheng ◽  
Jiayan Huang ◽  
Gua Yi

Purpose This paper aims to study the effect of current density of hydrogen charging on the semiconductor properties and pitting initiation of 2205 duplex stainless steel (DSS) passivation film. Design/methodology/approach In this work, the 2205 DSS is pre-hydrogenated and passivated. Then, the passivation film is tested by electrochemical impedance method, Mott–Schottky curve method and dynamic potential scanning method. The influences of hydrogen on the properties of the passivation film and the corrosion behavior of the matrix were studied by analyzing the curves obtained in the electrochemical test. The surface of the passivation film after pre-hydrogenation and anodic polarization was observed by using the ultra-depth three-dimensional microscopy and the scanning electron microscope. The integrity, density and corrosion morphology of the passivation film were studied and discussed. Findings With the increase of the hydrogen current density, the growth of the passivation film is hindered, the concentrations of donor and acceptor in the film are increased, the conductivity of the passivation film increases. In the anodic polarization, the dimensional passive current density increases with the increase of the hydrogen current density, and the pitting potential is reversed, the more likely the sample is pitting. In general, hydrogen hinders the formation of the passive film on duplex stainless steel, which increases the concentration of point defects in the passive film. Finally, the passive film is easy to crack and pitting. Originality/value The performance of passive film is an important condition to influence the corrosion behavior of stainless steel. However, little research has been done on the effects of hydrogen on the electrochemistry and pitting sensitivity of 2205 DSS passivation films. The effect of hydrogen on semiconductor properties and pitting initiation of 2205 DSS passivation film is needed to be investigated.


2017 ◽  
Vol 728 ◽  
pp. 60-65
Author(s):  
Thanaporn Thonondaeng ◽  
Ghit Laungsopapun ◽  
Kittichai Fakpan ◽  
Krittee Eidhed

Single pass overlay welding of the ERNiCu-7 filler metal on the commercial pure titanium grade 2 and the 304 stainless steel using the gas tungsten arc welding (GTAW) process was studied. The ERNiCu-7 filler metal was overlay welded on the base metals with varying welding currents; it was 30A, 40A and 50A for the CP-Ti base metal and 50A, 60A and 70A for the 304SS base metal. The experimental results showed that the overlay CP-Ti welded-specimen, increasing of welding current increased bead width and decreased depth of penetration of weldment. While for the 304SS welded-specimen, increasing of welding current increased both bead width and depth of penetration. Suitable heat inputs to achieve good geometry of weldment for overlay welding were 348J/mm for CP-Ti welded-specimen and 558J/mm for 304SS welded-specimen.


2012 ◽  
Vol 706-709 ◽  
pp. 2008-2013
Author(s):  
Satoshi Sunada ◽  
Norio Nunomura ◽  
Kazuhiko Majima

In this experiment two kinds of 410L stainless steel, i.e., the first one is prepared by the I/M process and the second one is prepared by MIM process were used, and their corrosion behavior under stress in deionized water and the aqueous solution of 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33) has been investigated by Electrochemical Impedance Spectroscopy (hereafter shortened as EIS) under Slow Strain Rate Tensile (hereafter shortened as SSRT) test. The charge transfer resistance (Rct) of the I/M specimen is larger than that of the MIM specimen irrespective of under stress or non-stress, which means that the I/M specimen has the better corrosion resistance than the MIM specimen in the 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33) solution. It was also confirmed from the fracture surface observation that hydrogen embrittlement occurred on the MIM specimen in the aqueous solution of 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33). This result would be confirmed to be due to the existing impurities and defects in the MIM specimen.


2012 ◽  
Vol 531 ◽  
pp. 47-50
Author(s):  
Xiao Liu ◽  
Jian She Li

The anodic polarization curves of 430 ferrite stainless steels with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of RE on pitting corrosion resistance of 430 ferrite stainless steels has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped RE2O2S and RES after adding RE to 430 ferrite stainless steesl. RE makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped RE inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 430 ferrite stainless steels.


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