Effect of Sn Addition on Corrosion Properties of As-Cast and Hot-Rolled AZ31 Magnesium Alloys

2017 ◽  
Vol 750 ◽  
pp. 124-128
Author(s):  
Yunus Turen ◽  
Didem Güzel ◽  
Huseyin Zengin ◽  
Yavuz Sun ◽  
Hayrettin Ahlatci

In this study, the effect of Sn addition on corrosion resistance of as-cast and hot rolled AZ31 magnesium alloy was investigated. Sn additions were made by 0.2 wt%, 0.5 wt% and 1 wt%. An electric resistance furnace was used to produce alloys. Hot rolling process was performed at 350 °C by 40% thickness reduction at one rolling pass. Microstructure characterizations were performed by optical (OM) and scanning electron microscope (SEM). Immersion tests and electrochemical analyses were performed to investigate the corrosion resistance of the alloys. A 3.5% NaCl working solution at room temperature was used in both corrosion tests. The results showed that Sn addition decreased the primary dentrite size and restricted the growth of secondary dentritic arm. The as-cast structures transformed to dynamically recrystallized grain structures after hot-rolling process in all the alloys. Corrosion resistance of AZ31 magnesium alloy tended to decrease with Sn addition. This decrease was more clear in homogenized and hot-rolled states while there were some flactuations in as-cast states.

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Ming Chen ◽  
Xiaodong Hu ◽  
Hongyang Zhao ◽  
Dongying Ju

A large reduction rolling process was used to obtain complete dynamic recrystallization (DRX) microstructures with fine recrystallization grains. Based on the hyperbolic sinusoidal equation that included an Arrhenius term, a constitutive model of flow stress was established for the unidirectional solidification sheet of AZ31 magnesium alloy. Furthermore, discretized by the cellular automata (CA) method, a real-time nucleation equation coupled flow stress was developed for the numerical simulation of the microstructural evolution during DRX. The stress and strain results of finite element analysis were inducted to CA simulation to bridge the macroscopic rolling process analysis with the microscopic DRX activities. Considering that the nucleation of recrystallization may occur at the grain and R-grain boundary, the DRX processes under different deformation conditions were simulated. The evolution of microstructure, percentages of DRX, and sizes of recrystallization grains were discussed in detail. Results of DRX simulation were compared with those from electron backscatter diffraction analysis, and the simulated microstructure was in good agreement with the actual pattern obtained using experiment analysis. The simulation technique provides a flexible way for predicting the morphological variations of DRX microstructure accompanied with plastic deformation on a hot-rolled sheet.


2011 ◽  
Vol 239-242 ◽  
pp. 2233-2239
Author(s):  
Zhi Qian Chen ◽  
Wen Bin Yu ◽  
Mei Tao Ouyang

The formulation design and fundamental experiments of O/W type emulsions as lubricant and coolant in the hot rolling process of magnesium alloy were conducted in this work. The main components of emulsion were determined by the comparision of some candidates of base oil, polar oil additive and emulsifier in microstructure and properties, respectively. It is found that the conservation stability of emulsions is mainly dominated by the emulsifier concentration and type. The results showed that the suitable stability and microstructure was obtained by using compound emulsifier of nonionic and anionic surfactants. The feasible contents of both emulsifier and polar agents are about 10 percent, respectively.


CORROSION ◽  
10.5006/2749 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 958-970 ◽  
Author(s):  
Majid Shahsanaei ◽  
Sadegh Pour-Ali ◽  
Ali-Reza Kiani-Rashid ◽  
Sannakaisa Virtanen

A series of hot rolling processes with different reduction percentages (10%, 30%, and 50%) were applied to a high-carbon high-chromium tool steel (2HCTS). Microstructural evolutions, wear behavior, high-temperature oxidation, and aqueous corrosion properties were investigated. The results revealed the breakage and dissolution of primary carbides and a uniform carbide distribution after the hot rolling process. It was proposed that the presence of higher amounts of dissolved chromium in the hot rolled samples leads to the formation of Cr-rich oxides with more protection and less porosity at high temperatures, as well as an improved corrosion behavior in 3.5 wt% NaCl solution. This improvement in the corrosion behavior is not at the expense of the degradation of wear resistance. Probable mechanisms for carbides dissolution are also discussed.


2020 ◽  
Vol 989 ◽  
pp. 699-704
Author(s):  
Nikita S. Deryabin ◽  
Sergey M. Chernyshev ◽  
Sergey N. Veselkov

Under the current conditions, the consumption of special purpose alloys or steels is growing. This is due to the development of the import substitution program. It should be noted, that such materials possess specific deformation behavior, which requires providing particular conditions of a hot rolling process. One of the characteristics of the deformation behavior is the narrow thermal plastic range. Therefore, it is necessary to conduct a hot rolling in several stages, which include interchange of heating and rolling processes. For the purpose to resolve the issue, the experience of the multilayer hot rolling of plates has been investigated where all advantages of this way of a hot rolling process were used. Based on the method of the multilayer hot rolling, the pack rolling has been developed which gives the possibility of production of hot-rolled plates from special purpose alloys or steels.


2017 ◽  
Vol 750 ◽  
pp. 113-117
Author(s):  
Yavuz Sun ◽  
Nazif Ugur Aydın ◽  
Yunus Turen ◽  
Hayrettin Ahlatci ◽  
Huseyin Zengin

This study investigates the effect of Ti addition (0, 0.2, 0.5, 1wt%) on corrosion resistance of as-cast and hot rolled AM60 magnesium alloy. Corrosion behaviors were investigated by immersion tests and electrochemical analysis. The results showed that Ti addition altered the microstructure of as-cast AM60 magnesium alloy by decreasing the amount of β-Mg17Al12 eutectic phase. Homogenization treatment resulted in the dissolution of the most of the β-Mg17Al12 phases. Homogenized samples exhibited the lowest corrosion rate in immersion test while the best corrosion resistance was found for hot-rolled samples in electrochemical test. In hot-rolled state, Ti addition led to a slight change in the corrosion resistance of AM60 magnesium alloy.


2011 ◽  
Vol 399-401 ◽  
pp. 264-267
Author(s):  
Hai Yan Wang ◽  
Hui Ping Ren ◽  
Le Han ◽  
Zi Li Jin ◽  
Hao Sun

Microstructure of X80 pipeline steel with different hot rolling process was compared using Optical microscopy (OM), Bulk X-ray texture and micro orientation analysis was carried out by Orientation distribution function (ODF) and Electron back-scattered diffraction (EBSD), to analyze the various texture components of the pipeline steels under two different rolling processes. The results show that the final microstructures under the two schedules both present typical acicular ferrite characteristic. On the other side, the corresponding textures were found mainly comprised of two fibers in the rolling and normal direction in hot rolled X80 steel plate, there were obvious {112} , {110} , and {111} fiber, which seemed to be related with the mechanical properties anisotropy. Therefore, the influences of the microstructure and texture on the anisotropy were also discussed in this paper.


2011 ◽  
Vol 291-294 ◽  
pp. 137-140
Author(s):  
Yao Min Zhu ◽  
Qiu Ran Gao ◽  
Feng Zhang Ren ◽  
Shi Jie Fang

The effects of the hot-rolling process on microstructures and strength were investigated for two kinds of magnesium alloy Mg-Zn-Y and Mg-Zn-Y-Nd. In comparison with the as-cast alloys, the tensile strength of Mg-Zn-Y and Mg-Zn-Y-Nd both increases 45%, whereas their elongation decreases 73%, 60% via hot-rolling process, respectively. The results show that the dynamic recrystallization process and the pining effect of I-phase during hot rolling contribute to the fine-grained structure formation. The hot-rolling process has refined the grain size greatly.


2012 ◽  
Vol 735 ◽  
pp. 289-294 ◽  
Author(s):  
Toshiaki Manaka ◽  
Goroh Itoh ◽  
Nguyen The Loc ◽  
Yoshinobu Motohashi ◽  
Takaaki Sakuma

The Zn-22Al alloy with fine-equi-axed has been well known as a typical superplastic metallic material [1]. In the present study, The Zn-22Al alloy ingot of 20mm thickness was homogenized, either air-cooled or water-quenched, and then hot-rolled to a thickness of 2mm. Microstractural observation, showed that in the air-cooled specimens lammellar microstructure was formed after homogenization, and become fragmented to fine-grained microstructure as the hot rolling process proceeded. In the water-quenched specimens, equi-axed fine-grained microstructure with grain size under 2.1μm was attained and maintained throughout the hot rolling process.


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