scholarly journals Effect of Heat Treatment on Microstructure and Properties of Clad Plates 316L/Q370qE

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1556 ◽  
Author(s):  
Zimeng Wang ◽  
Shumei Kang ◽  
Meiling Xu ◽  
Yanqiang Cheng ◽  
Ming Dong

Mechanical properties of Q370qE carbon steel can be improved by cladding it with 316L stainless steel. After rolling these materials together, microstructure, hardness, shear strength, and corrosion properties of the cladded metals were evaluated. Hardness and shear tests were performed according to appropriate standards to evaluate the bonds. The results show that the remarkable diffusion of Ni and Cr formed a hard transition zone. The width of this diffusion zone increases with increasing temperature. The shear strength of the clad interface reached a minimum of 385 MPa. In addition, the surfaces of samples were examined by neutral salt spray (NSS) tests and potentiodynamic polarization tests to examine corrosion behavior. The 316L side primarily exhibited pitting corrosion, while the Q370qE side was dominated by uniform corrosion.

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 930
Author(s):  
Juan Jesús Alba-Galvín ◽  
Leandro González-Rovira ◽  
Francisco Javier Botana ◽  
Maria Lekka ◽  
Francesco Andreatta ◽  
...  

The selection of appropriate surface pretreatments is one of the pending issues for the industrial application of cerium-based chemical conversion coatings (CeCC) as an alternative for toxic chromate conversion coating (CrCC). A two-step surface pretreatment based on commercial products has been successfully used here to obtain CeCC on AA2024-T3 and AA7075-T6. Specimens processed for 1 to 15 min in solutions containing CeCl3 and H2O2 have been studied by scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), glow discharge optical emission spectroscopy (GDOES), potentiodynamic linear polarization (LP), electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. SEM-EDX showed that CeCC was firstly observed as deposits, followed by a general coverage of the surface with the formation of cracks where the coating was getting thicker. GDOES confirmed an increase of the CeCC thickness as the deposition proceed, the formation of CeCC over 7075 being faster than over 2024. There was a Ce-rich layer in both alloys and an aluminum oxide/hydroxide layer on 7075 between the upper Ce-rich layer and the aluminum matrix. According to LP and EIS, CeCC in all samples offered cathodic protection and comparable degradation in chloride-containing media. Finally, the NSS test corroborated the anti-corrosion properties of the CeCC obtained after the commercial pretreatments employed.


Author(s):  
Feng Yu ◽  
Yongchen Song ◽  
Weiguo Liu ◽  
Yanghui Li ◽  
Jiafei Zhao

The production of methane from hydrate reservoir may induce deformation of the hydrate-bearing strata. The research on mechanical properties of methane hydrate and establishing an efficient methane exploitation technology appear very important. In this paper, a low-temperature high-pressure triaxial test system including pressure crystal device (sample preparation system) was developed. A series of triaxial shear tests were carried out on artificial methane hydrate samples. The mechanical behavior was analyzed. The preliminary results show that the shear strength of methane hydrate increases with the increase of confining pressure and strain rate. While it increases with the decrease of temperature. Moreover, the secant modulus increases with the enhancement of strain rate and the decrease of confining pressure.


2013 ◽  
Vol 745-746 ◽  
pp. 33-38 ◽  
Author(s):  
Shi Jie Zhu ◽  
Li Guo Wang ◽  
Jin Jin ◽  
Jing Wang ◽  
Yu Feng Sun ◽  
...  

In order to improve the mechanical properties and processing performance of the Mg alloys, and to prevent magnesium alloy from non-uniform corrosion and too fast degradation in the degradation process, the biological medical Mg-Zn-Y-Nd alloy was modified by the friction stir processing (FSP) technique in this paper. The microstructural evolution and phase constitute of the stir zone of Mg-Zn-Y-Nd alloy were investigated, the microhardness and the corrosion properties of the alloy after FSP process was studied. The results showed that the FSP parameters had significant influence on the stir zone and thermo-mechanically affected zone. The stir zone experienced severe plastic deformation and complete dynamic recrystallization after FSP. The stir zone consists of fine equiaxed recystallized grains, and thermo-mechanically affected zone (TMAZ) has deformed grain structure. The second phase distributed along grain boundaries in as-cast state was broken during the FSP and transformed into fine, uniform and dispersed particles in the grains. After FSP, the size of grains was reduced from 50μm (as-cast alloy) to 1-2μm. However, the second phase constitution didnt change. The alloy obtained good comprehensive mechanical properties after FSP. The microhardness of alloy after FSP increased from 39HV (as-cast alloy) to 64HV(FSPed alloy). The results of electrochemical tests in simulated body fluid showed that the corrosion potential of FSP alloy increased and corrosion current density decreased, which confirmed the uniform corrosion of FSPed alloy.


2016 ◽  
Vol 63 (2) ◽  
pp. 82-88 ◽  
Author(s):  
Shengsong Ge ◽  
Menglong Li ◽  
Qian Shao ◽  
Ke Liu ◽  
Junxiang Wang ◽  
...  

Purpose – This paper aims to clarify the effect of metal ions added in the γ-glycidoxypropyltrimethoxysilane (γ-GPS) solutions on the anti-corrosion properties of the γ-GPS coatings on cold-rolled iron (CRI). Design/methodology/approach – The transformations of functional groups involved in reactions during the coating process were characterized by Fourier transformed infrared spectroscopy (FTIR), and the thickness of the γ-GPS coatings on the CRI substrates was measured using high-powered microscopy. The anti-corrosion properties of γ-GPS-treated samples were evaluated by neutral salt spray tests, polarization curves and electrochemical impedance spectroscopy measurements. Findings – The results show that Zn2+ and Mg2+ in the γ-GPS solutions promote the formation of Si-O-Si and Si-O-Fe bonds and improve the anti-corrosion properties of the γ-GPS coatings on CRI. However, Al3+ and Na+ in the γ-GPS solutions do not play this role. Originality/value – Although there have been previous research studies on the γ-GPS coatings on CRI, this paper is the first to study the effect of metal ions added in the silane solutions on the anti-corrosion properties of the γ-GPS coatings, and it has been confirmed that the anti-corrosion properties changed when Zn2+ (or Mg2+) is present.


Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1357 ◽  
Author(s):  
Jaromír Wasserbauer ◽  
Martin Buchtík ◽  
Jakub Tkacz ◽  
Stanislava Fintová ◽  
Jozef Minda ◽  
...  

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.


2013 ◽  
Vol 807-809 ◽  
pp. 1140-1146 ◽  
Author(s):  
Yi Xuan Chen ◽  
Xiu Li Sun ◽  
Zhi Hua Li

The objective of this work is to investigate the stimulation effect of the addition of alkali on the fly ash and slag for stabilizing dredged silt. Based on the test results, a viable alternative for the final disposal of dredged silt as subgrade construction materials were proposed. For this purpose, several mixtures of dredged silt-fly ash-slag and alkali were prepared and stabilized/solidified. In this system, fly ash and slag were used as hardening agents (solidified materials) of dredged silt and alkali was used as activator of fly ash and slag. The shear strength of the mixture was tested by several direct shear tests. Furthermore, X-Ray Diffraction (XRD) analysis was used to determine the hydration products of the system. The specimens were tested in order to determine the shear strength changes versus hydration time and the alkali content. It is indicated that mechanical properties of solidified silt are improved significantly by addition of fly ash and slag stimulated by alkali.


2015 ◽  
Vol 227 ◽  
pp. 147-150
Author(s):  
Agnieszka Nagrabia ◽  
Maciej Sowa ◽  
Wojciech Simka ◽  
Artur Maciej

Zn-Ni and Zn-Co monolayer and Zn-Ni/Zn-Co multilayer (from 2 to 128 layers) alloy coatings were formed on steel substrate by electrodeposition from acidic Zn-Ni bath and neutral Zn-Co bath. Samples were tested in salt chamber for corrosion resistance in neutral salt spray. Open circuit potential measurement and gravimetric study of corrosion were carried for samples immersed in the 5% NaCl solution.It was found that coatings of Zn-Ni surface layer occurred higher corrosion resistance then the coatings of Zn-Co surface layer. Sixteen-layer coating with Zn-Ni surface layer proved to be most effective in protecting the steel substrate. Zn-Ni monolayer showed the lowest corrosion potential, which affects the corrosion properties. Sample weight changes during exposure to a corrosive environment are related to digestion of the coating and the formation of corrosion products.


2014 ◽  
Vol 618 ◽  
pp. 109-113
Author(s):  
Wei Jiang ◽  
Qing Jun Chen ◽  
Jun Shen ◽  
Fa Bi Zhang ◽  
Xian Liang Zhou ◽  
...  

For the bulk amorphous Fe24+xCo24-xCr15Mo14C15B6Y2(X=0, 2, 4, 6 and 17) alloy, the corresponding corrosion properties associated with glass forming ability (GFA) have been carried out. Neutral salt spray corrosion test results show that the Fe28Co20Cr15Mo14C15B6Y2 alloy has the minimum corrosion rate, followed by Fe26Co22Cr15Mo14C15B6Y2, Fe24Co24Cr15Mo14C15B6Y2, Fe30Co18Cr15Mo14C15B6Y2, Fe41Co7Cr15Mo14C15B6Y2 and Ti6Al4V alloys. Specifically, the Fe28Co20Cr15Mo14C15B6Y2 alloy with the highest GFA also has the best corrosion resistance. With the increasing of Co addition, the corrosion resistance of the FeCo-based bulk metallic glasses is first increases and then decreases, which has the same trend of GFA with the change of Co elements. Furthermore, corrosion morphology are different for FeCo-based BMGs with different Co content.


2013 ◽  
Vol 456 ◽  
pp. 438-441 ◽  
Author(s):  
Tian Yang ◽  
Cheng Zhang Peng ◽  
Lang Xiang ◽  
Huo Cao

The electroplated Ni-Co-Cr coatings were prepared on surface of a low carbon steel. The microstructure of the deposits were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD), the corrosion resistance of the deposits was evaluated using neutral salt-spray test and polarization measurement. The results show that the deposits are a Co and Cr solid solution in Ni with a grain size of 6.9~10.6nm, were nearly free of corrosion after neutral salt-spray tested 100 hours. With chromium content increasing, the coatings exhibited higher corrosion potential and lower corrosion current, which revealed excellent corrosion resistance.


2013 ◽  
Vol 745-746 ◽  
pp. 28-32 ◽  
Author(s):  
Shi Jie Zhu ◽  
Qiong Wu ◽  
Li Guo Wang ◽  
Qian Liu ◽  
Gao Chao Yue ◽  
...  

Magnesium alloys are promising candidate materials for cardiovascular stents due to their good biocompatibility and degradation property in human body. However, in vivo tests also show that improvement in mechanical property and corrosion resistance is necessary for wide application. In this study, hot extrusion and cyclic extrusion compression (CEC) were used on Mg-Zn-Y-Nd alloy, the effects of hot extrusion and CEC process on the microstructures, mechanical properties and corrosion properties of alloy were studied. The results showed that the microstructures of CEC treated Mg-Zn-Y-Nd alloy became finer and more homogenous, some nanoparticles which came from the cluster phase uniformly precipitated inside grains, alloy had good mechanical properties and corrosion resistance. The immersion test results in SBF solution at 37 for 24h showed that the alloy after CEC treatment is uniform corrosion.


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