Research on Mechanical and Corrosion Properties of Ti-Microalloyed Biomedical Cobalt-Based Alloy

2016 ◽  
Vol 852 ◽  
pp. 1168-1174
Author(s):  
Ya Ting Cao ◽  
Feng Wang ◽  
Qing Xuan Ran ◽  
Yu Lai Xu ◽  
Jun Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Phase Transformation ◽  
Aging Treatment ◽  
Physiological Saline ◽  
Corrosion Properties ◽  
Solution Treated ◽  
Cast Specimen ◽  
Mechanical And Corrosion Properties ◽  
Stable Passive

0.15 wt. % Ti-microalloyed Co-28.5Cr-5.9Mo-0.27C alloy has been developed by examining the effect of solution and aging treatment on microstructure, mechanical and corrosion properties. The results showed that elongation of the cast specimen were lower than 8%, while reached 18% after solution-treated at 1220 °C for 4 h. Phase transformation from austenite to martensite was observed after aging at 800°C and the amount of transformed martensite increased with aging time. Polarization tests of the samples after solution and aging treatment were carried out in physiological saline at 37 °C, which showed a stable passive film formed on the surface and no apparent pitting phenomenon occurred on the specimens, which indicated that heat treatment has not significant influence on the corrosion resistance of Co-Cr-Mo-0.27C-0.15Ti alloy.

Effect of heat treatment on microstructure and corrosion resistance of extruded ZK80 Mg alloy

2019 ◽  
Vol 9 (9) ◽  
pp. 1092-1099
Author(s):  
Fenghong Cao ◽  
Chang Chen ◽  
Zhenyu Wang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Aging Time ◽  
Room Temperature ◽  
Aging Treatment ◽  
Corrosion Process ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Corrosion Properties

The corrosion characteristics and corrosion mechanism of the extruded ZK80 alloy with different states soaking in 3.5% NaCl solution at room temperature were analyzed via OM, SEM, EDS, XRD and static weightlessness method and other experimental analysis methods. The results show that when the aging temperature is constant, and the corrosion rate decreases with the lengthen of aging time, while when the corrosion time is constant, the corrosion rate increases with the increase in aging time. Appropriate aging treatment not only refines the grain of the alloy, but also precipitates the Mg–Zn phase which can effectively prevent the corrosion process and improve the anti-corrosion properties of the alloy. The main corrosion characteristics of the alloy are filamentary corrosion and pitting corrosion.

scholarly journals Stress-corrosion resistance of the EN AW-AlZn5Mg1,5CuZr alloy in different heat treatment states

2013 ◽  
Vol 20 (4) ◽  
pp. 39-44
Author(s):  
Lesław Kyzioł
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Stress Corrosion ◽  
Alloy System ◽  
Mg Alloys ◽  
Corrosion Properties ◽  
Chemical Constitution ◽  
Stress Corrosion Resistance ◽  
Mechanical And Corrosion Properties

ABSTRACT The effect of heat treatment of the plastically worked 7000 series Al-Zn-Mg aluminium alloy system on its stress-corrosion resistance is examined. For the same chemical constitution, the effect of heat treatment on mechanical and corrosion properties of Al-Zn-Mg alloys systems is remarkable. It was proved that a parameter having significant effect on corrosion properties of the alloy is the rate of alloy cooling after heat treatment. This conclusion is confirmed by observation of structural forms which fully reflect mechanical and corrosion properties of the alloy.

scholarly journals Influences of Heat Treatment on the Thermal Diffusivity and Corrosion Characterization of Al-Mg-Si alloy

2021 ◽  
Vol 59 (8) ◽  
pp. 582-588
Author(s):  
Yu-Mi Kim ◽  
Se-Weon Choi ◽  
Young-Chan Kim ◽  
Chang-Seog Kang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Thermal Diffusivity ◽  
Corrosion Rate ◽  
Aging Treatment ◽  
Solute Concentration ◽  
Scanning Calorimetry ◽  
Mg2si Phase ◽  
Solution Treated ◽  
Treated Sample

The effect of the heat treatment on the Mg2Si phase in Al-Mg-Si alloy was investigated by a laser flash apparatus (LFA), Differential scanning calorimetry (DSC) and corrosion test. The alloy samples were solution treated at 590 oC for a half hour followed by warm water quenching, and then aged in air at 180, 200 and 240 oC for 5 hours. The results showed that the corrosion resistance of the solid solution treated sample was more improved than the as cast sample. Aging treatment also helped increase corrosion resistance at room temperature. It is thought that the fine Mg2Si precipitation phase on the grain had a more positive effect on improving corrosion resistance than crystallization of the Mg2Si phase on the grain boundaries. Corrosion rate also decreased with increasing aging treatment. The corrosion rate of AT240 was reduced to 1.16 MPY compared with the AT180 test piece, which had a corrosion rate of 3.79 MRY. The solution treated sample also showed lower thermal diffusivity than the aged samples. The thermal diffusivity increased as the solute concentration of Mg and Si in the a-Al matrix rapidly decreased during aging treatment. On the other hand, the thermal diffusivity of the aged samples, in which precipitation was completed by the aging process, decreased as the temperature rose. The thermal conductivities of all samples were similar near 250 oC when the β'' phase and β' precipitation was completed.

On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

The structure and properties of sheets from the new alloy V-1381 of the Al – Mg – Si system

2021 ◽  
Vol 5 ◽  
pp. 18-27
Author(s):  
A. A. Selivanov ◽  
◽  
K. V. Antipov ◽  
Yu. S. Oglodkova ◽  
A. S. Rudchenko ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Arc Welding ◽  
Structure And Properties ◽  
Strengthening Phase ◽  
Critical Rate ◽  
Corrosion Properties ◽  
Β Phase ◽  
Mechanical And Corrosion Properties ◽  
20 Nm ◽  
6Xxx Series

The results of the development of a new alloy of the Al – Mg – Si system of the 6xxx series, which received the V-1381 grade, are presented. The influence of the composition and modes of heat treatment on the mechanical and corrosion properties of sheets with a thickness of 1,0 and 3,0 mm, manufactured under the conditions of FSUE “VIAM”, was investigated. Average level of sheet properties: UTS = 410 MPa, YTS = 360 MPa, El = 11.5 %; fatigue crack growth (dl/dN) = 0,59 mm/kcycle at ΔK = 18,6 MPa·m1/2, intergranular corrosion ≤ 0,15 mm, exfoliation corrosion 4 points. It was found that the structure of the sheets is recrystallized, the main strengthening phase is the coherent matrix β’(Mg2Si)-phase evenly distributed in the volume of grains with a high density. There is also a heterogeneous origin of β′-phase on dislocations and dispersoids. At grain boundaries there are zones free from emissions with a width of 15 – 20 nm. Dispersoids of various morphologies are observed in the tested samples. Temperature and heat values of phase transformations in ingots and sheets are determined and established liquidus and solidus points. The sheet weldability was evaluated by automatic argon-arc welding and the critical rate of deformation of the weld metal during crystallization was determined, at which no cracks were formed in it. Laser welding mode has been developed to ensure optimal formation of geometric parameters of the weld.

Effect of homogenization temperature and soaking time on the microstructure and corrosion properties of a twin roll casted AA3003

CORROSION ◽  
10.5006/3813 ◽  
2021 ◽  
Author(s):  
Donovan Verkens ◽  
Reynier Revilla ◽  
Mert Günyüz ◽  
Cemil Işıksaçan ◽  
Herman Terryn ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Exchangers ◽  
Corrosion Behaviour ◽  
Life Time ◽  
Homogenization Temperature ◽  
Corrosion Properties ◽  
Cross Sectional ◽  
The Impact ◽  
Twin Roll

The AA3003 alloy is widely used as fin material in heat exchangers. The life time of these heat exchangers is mostly determined by their corrosion properties. Twin roll casting (TRC) of AA3003 material is known to often result in the formation of a macrosegregation area of alloying elements towards the centre plane of the casted strip (centre line segregation = CLS). Considering the potential exposure of cross-sectional areas of TRC material in the heat exchanger fin application, and the relatively high corrosion susceptibility of the CLS, the study of this region is of key importance to understand the microstructural effects on the resulting corrosion mechanisms and kinetics for these materials. Typically the alloys are homogenized to bring the microstructures closer to an equilibrium state, but the impact of this heat treatment on the corrosion properties is insufficiently studied. Therefore, this study investigates the effect of different homogenization procedures on the corrosion properties of the CLS and the interaction of the intermetallic particles with the surrounding aluminium matrix. This work shows that the pitting corrosion resistance is greatly dependent on the homogenization temperature, with better corrosion resistance obtained with higher temperature, especially near the CLS. This difference in corrosion behaviour is completely attributed to a difference in microstructure and not to an oxide layer effect. Furthermore, it is observed that not only temperature will have a large influence on the corrosion resistance, but duration of the heat treatment as well.

scholarly journals Comparison of Corrosion Resistance in Physiological Saline Solution of Two Austenitic Stainless Steels – 316LV and REX734

2017 ◽  
Vol 11 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Eliza Romańczuk ◽  
Zbigniew Oksiuta
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Saline Solution ◽  
Austenitic Stainless Steels ◽  
Physiological Saline ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Physiological Saline Solution ◽  
Superior Corrosion Resistance ◽  
Lower Nickel

AbstractIn this work two austenitic stainless steels, REX734 and 316LV were tested in terms of their microstructure and corrosion properties. The REX734 is a newer generation stainless steel, with modified chemical composition, in comparison to the 316LV grade. Potentiodynamic study of corrosion resistance was conducted in physiological saline solution (0.9% NaCl solution). In spite of the similarities of microstructure, grain size and phase structure in both materials, the corrosion tests revealed that the REX734, with lower nickel and higher nitrogen content, had better corrosion resistance than 316LV. Repassivation potential in the REX734 was almost six times higher than for the 316LV steel. Superior corrosion resistance of the REX734 steel was also confirmed by surface observations of both materials, since bigger and more densely distributed pits were detected in 316LV alloy.

The Characteristics of Weld Metal Zone Welded with Various Filler Metals

2013 ◽  
Vol 690-693 ◽  
pp. 2673-2677
Author(s):  
Kyung Man Moon ◽  
Mun Jin Nam ◽  
Yeon Chang Lee ◽  
Yun Hae Kim ◽  
Jae Hyun Jeong
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Post Weld Heat Treatment ◽  
Fuel Oil ◽  
Corrosion Properties ◽  
Repair Welding ◽  
Piston Crown ◽  
Filler Metals ◽  
Weld Heat

Recently, the fuel oil of diesel engines of marine ships is being changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the wear and corrosion in all parts of the engine, such as cylinder liner, piston crown, and spindle and seat ring of exhaust valves has predominantly increased. Thus, the repair welding of the piston crown is a unique method to prolong its life in a economical point of view. In this case, filler metals with a high corrosion and wear resistance are mainly being used for repair welding. However, the piston crown on the ships job site is often actually being welded with mild filler metals. Therefore, in this study, mild filler metals, such as E4301, E431316, and E4316, were welded to the SS401 steel as the base metal, and the corrosion properties of their weld metals with and without post weld heat treatment were investigated with some electrochemical methods in 0.1% H2SO4 solution. The weld metal welded with E4301 filler metal exhibited the best corrosion resistance among the filler metals in the case of no heat treatment, however, its resistance was considerably decreased due to the post weld heat treatment (annealing:625°C, 2hr). In particular, the weld metal of E4316 exhibited relatively a good corrosion resistance by the post weld heat treatment.

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