Effect of Solution Heat Treatment on Corrosion Kinetics Of Zirconium in 20 Percent Hydrochloric Acid At High Temperature and Pressure

CORROSION ◽  
1963 ◽  
Vol 19 (5) ◽  
pp. 169t-179t ◽  
Author(s):  
WILLIAM E. KUHN
Keyword(s):  
Heat Treatment ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Water Quenching ◽  
Precipitate Phase ◽  
Corrosion Rates ◽  
Corrosion Kinetics ◽  
Kinetics Of

Abstract An investigation has been made of the influence of amount and distribution of precipitate phase on the corrosion kinetics of “low purity” zirconium in 20 percent hydrochloric acid at 200 C. It was found that minimum corrosion rates, coincident with minimum values of activation energy and frequency factor in the Arrhenius relationship, were obtained by solution heat treatment at 700 C followed by water quenching. Such heat treatment gave a corrosion rate equivalent to that of alpha annealed iodide zirconium. A maximum corrosion rate was obtained by a beta solution treatment at 890 C followed by water quenching, whereas beta solution treatment at 1000 C gave sharply reduced corrosion rates. Nature of distribution of the precipitate phase profoundly influenced corrosion rate. A discontinuous pattern of intergranular and transgranular globular particles was substantially less deleterious than the same amount of impurity phase finely disseminated throughout the microstructure. The results of the investigation are discussed in terms of the possible roles of chlorine and hydroxyl ions in the corrosion mechanism. Relative effects on corrosion kinetics of statistical distributions of active sites (each characteristic of lattice configurations produced by lattice defects, solute atoms and precipitation phenomena) are also considered.

scholarly journals Evaluation of AA6061-T6 behavior subjected to Cyclic Solution Treatment

2020 ◽  
Vol 23 (4) ◽  
pp. 383-387
Author(s):  
Najmuldeen Yousif Mahmood ◽  
Ahmed Ameed Zainulabdeen ◽  
Jabbar Hussein Mohmmed ◽  
Hasanain Abd Oun
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Tensile Test ◽  
Aging Time ◽  
Vickers Hardness ◽  
Solution Heat Treatment ◽  
Treatment Process ◽  
Solution Treatment ◽  
Heat Treatment Process ◽  
Precipitate Phase

The effects of the repeated solution heat treatment on hardness, tensile strength and microstructure of aluminum were studied. For this purpose, an alloy of AA6061-T6 was undergo to cyclic solution heat treatment process which is composed of repeated period (10 min) held at 520 °C for 1, 4, 8 and 12 cycles. The hardness was tested for five aging times (as quenching, one week, three weeks, one month and five months) to all cycles (1, 4, 8 and 12) firstly and it is found that the hardness of five months as aging time for all cycles has the best results (90Hv) as compared with others (as quenching, one week, three weeks, and one month), so it was adopted for all cycles to implement the tensile test and the microstructure. Hardness results were improved to Vickers hardness of (90Hv) with increasing of cycles up to 8 cycles then decreasing after that to (45Hv). Tensile results were showed an increment (34%) also for the same group of 8 cycles compared with (17%) and (9%) for 4 and 12 cycles, respectively. Microstructure is revealed that whenever cycles are increased, the precipitate phase in alloy is increased also, thus, it is improved the hardness and tensile strength.

scholarly journals Effect of Post Weld Heat Treatment on the Microstructure and Electrochemical Characteristics of Dissimilar Material Welded by Butter Method

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4512
Author(s):  
Umer Masood Chaudry ◽  
Hafiz Waqar Ahmad ◽  
Muhammad Rehan Tariq ◽  
Ameeq Farooq ◽  
Muhammad Kashif Khan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Parameters ◽  
Post Weld Heat Treatment ◽  
Dissimilar Material ◽  
Electrochemical Characteristics ◽  
Corrosion Kinetics ◽  
Before And After ◽  
C 50 ◽  
Kinetics Of ◽  
Weld Heat

In the present study, the effect of post weld heat treatment (PWHT) on the microstructure and corrosion kinetics of butter welded Nickel Alloy 617 and 12Cr steel was investigated. Buttering was carried out on the 12Cr side with the Thyssen 617 filler metal. Furthermore, post weld heat treatment (PWHT) was conducted at 730 °C with a holding time of 4 h followed by furnace cooling. Optical Microscopy (OM) was conducted to study the microstructural evolution in dissimilar material welding as a result of PWHT. Moreover, Scanning Electron Microscopy with energy dispersive spectroscopy (SEM-EDS) was employed to determine the elemental concentrations in all important regions of the butter weld before and after the PWHT. In addition, the effect of PWHT on the corrosion kinetics of the butter weld was also investigated by potentiodynamic polarization measurements in 5 wt.% NaCl + 0.5 wt.% CH3COOH electrolyte at room temperature, 30 °C, 50 °C and 70 °C. The corrosion activation parameters were also determined for both the samples by using Arrhenius plots. The results revealed the higher susceptibility of corrosion of the butter weld after PWHT, which was attributed to the reduced Cr content in the heat affected zone of the 12Cr region due to the sensitization effect of the heat treatment, resulting in higher corrosion rates.

Study on Microstructures and Mechanical Properties of Die Casting Mg-xGd-3Y-0.5Zr Alloys

2013 ◽  
Vol 690-693 ◽  
pp. 44-48
Author(s):  
Feng Wang ◽  
Zhi Wang ◽  
Zheng Liu ◽  
Ping Li Mao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Solution Heat Treatment ◽  
Die Casting ◽  
Solution Treatment ◽  
Small Variation ◽  
Strength Increase ◽  
Microstructures And Mechanical Properties ◽  
Zr Alloys

In this paper, developed a non-aluminum die casting magnesium alloys were studied based on Mg-xGd-Y-Zr（x=6, 8, 12 wt.%）alloys in cold chamber press. The microstructures and mechanical properties of die casting GWK alloys have been investigated using OM, SEM, XRD, EDS and mechanical property test. The experimental results show that with increasing Gd content of Mg-xGd-Y-Zr alloys, the tensile strength increase, but elongation decrease. In particular, die casting GWK alloys after short-term and low-temperature solid solution treatment (T4) have a small variation in grain size and more uniform microstructures, and the second phases distribute at the grain boundaries in form of discontinuous rod shape or granule shape, which result in an obvious improvement in tensile mechanical properties of alloys. The Mg-12Gd-3Y-0.5Zr die casting alloy exhibit maximum tensile strength after solution heat treatment, and the value is 269MPa at room temperature. The effect of solution heat treatment on die casting Mg-xGd-Y-Zr alloys was also discussed.

Effect of the Two-Step Solution Heat Treatment on the Microstructure of Semisolid Cast 7075 Aluminum Alloy

2012 ◽  
Vol 488-489 ◽  
pp. 243-247 ◽  
Author(s):  
Saowalak Kongiang ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin ◽  
Sirikul Wisutmethangoon
Keyword(s):  
Heat Treatment ◽  
Treatment Condition ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Heat Treatment Condition ◽  
Single Step ◽  
Eutectic Phase ◽  
Solution Treated ◽  
The Matrix ◽  
Black Particle

Effect of the two-step solution heat treatment on the microstructure of semisolid cast 7075 aluminium alloy has been studied. The microstructure of the as-cast specimens mainly consisted of matrix-α (Al) and grain boundary (GB)-eutectic phase (α-Al + Mg(Zn,Cu,Al)2). After solution treating, coarse black particles were found to form in the single-step solution treated specimens at the condition of 450 °C for 8 h and 480 °C for 1 h, respectively. Two-step solution heat treatment resulted in the reduction of coarse black particle formation while maintaining the same amount of eutectic MgZn2phase dissolution as the high temperature single-step solution treatment. Therefore, the two-step solution heat treatment enables alloying elements dissolved into the matrix without overheating and hence decreases coarse black particles. The optimum two-step solution heat treatment condition derived from this study was 400 °C for 8 h + 450 °C for 4 h.

Optimisation of the Solution Heat Treatment of Rheo-Processed Al-Cu-Mg-(Ag) Alloys A206 and A201

2009 ◽  
Vol 618-619 ◽  
pp. 353-356 ◽  
Author(s):  
E.P. Masuku ◽  
Heinrich Möller ◽  
R.D. Knutsen ◽  
L. Ivanchev ◽  
Gonasagren Govender
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Dsc Analysis ◽  
Optimum Solution ◽  
Hardness Values

The traditional solution treatment cycles that are currently applied to rheo-processed A201 are mostly those that are used for conventional castings. These solution treatments are not necessarily the optimum solution treatments for rheo-processing. As a result, DSC analysis was done to optimize this heat treatment. The new solution treatment, which consists of higher temperatures and shorter times (515°C/5h, followed by 570°C/10h), resulted in slightly higher hardness values for both alloy A206 and A201.

Solution Heat Treatment of 7075 Aluminum Alloy Affected on Anodic Oxide Layer

2016 ◽  
Vol 867 ◽  
pp. 19-23 ◽  
Author(s):  
Itsaree Iewkitthayakorn ◽  
Somjai Janudom ◽  
Narissara Mahathaninwong
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Solution Treatment ◽  
Secondary Phase ◽  
Anodic Oxide ◽  
Al Alloy ◽  
Heat Treated

This research focused on the effect of solution heat treated microstructures on anodic oxide formations of casting 7075 Al alloy. The casting specimens were solution heat treated at 450°C for various holding. The results showed that the quality of anodic oxide film on the specimen with 4h solution heat treatment time was higher than that of at other conditions. Because its microstructures obtained the lowest amounts of secondary phase particles leading to improve the quality of oxide film and also reduce defects in oxide film. On the other hand, coarse black particles of Mg2Si formed increasingly in microstructures of specimens after solution treatment at prolong holding time of 8h and 16h resulted in discontinues oxide films forming on them.

scholarly journals Selection of optimal solution heat treatment of the casting cylinder heads

2018 ◽  
Vol 157 ◽  
pp. 02053 ◽  
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Denisa Závodská
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Crack Nucleation ◽  
Particle Density ◽  
Solution Treatment ◽  
Optimal Solution ◽  
Solution Temperature ◽  
Selection Of

The effect of solution treatment on mechanical properties (UTS, elongation, Brinell hardness) and microstructure (Si-morphology and Si-size) of an aluminium alloy (A356) used for casting cylinder heads was studied. The tests were carried out with specimens machined from the bulkheads of V8 engine blocks cast by the low pressure process. The samples were tested in as-cast and T6 heat treating conditions (solution heat treatment at 530°C with different time - 2, 3, 4, 5, 6, 7 hours, quenching in water at 20°C and precipitation hardened for 4 hour at 160°C). The results show that used heat treatment improves mechanical properties of the cylinder head casts. Tensile strength and hardness of specimens increase with solution treatment time. The hardness is a reflection of solution strengthening and silicon particle distribution in matrix. Solution temperature 530°C and 5 hours solution time is appropriate to obtain better morphology and distribution of Si particles in microstructure. Prolonged solution treatment (more than 5 hours) leads to a coarsening of the Si particles, while the numerical Si density decreases. As the particle density decreases, a fewer number of sites are available for crack nucleation, and hence, the fracture properties are improved. The data obtained from this study will be used to improve process control, and to help the selection of heat treatment of the casting for future products.

scholarly journals The Effect of Cyclic Solution Heat Treatment on the Martensitic Phase Transformation and Grain Refinement of Co-Cr-Mo Dental Alloy

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 861 ◽  
Author(s):  
Shahab Zangeneh ◽  
Hamid Reza Lashgari ◽  
Shaimaa Alsaadi ◽  
Sara Mohamad-Moradi ◽  
Morteza Saghafi
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Grain Refinement ◽  
Solution Heat Treatment ◽  
Thermal Stresses ◽  
Solution Treatment ◽  
Martensite Phase ◽  
Cyclic Heat Treatment ◽  
Uniform Dispersion ◽  
Ε Martensite

The present study was undertaken to investigate the effect of continuous and discontinuous (cyclic) solution heat treatment on the athermal and isothermal ε martensite phase transformation in Co-28Cr-6Mo-0.3C implant alloy. The results showed that the cyclic solution heat treatment induced more of the athermal ε martensite phase in the alloy than that of the continues one. In addition, the cyclic heat treatment contributes to the development of more isothermal martensite phase during isothermal aging at 850 °C and, moreover, grain refinement in the area beneath the sample surface. The severity of grain refinement was highly significant adjacent to the surface and decreased by increasing the distance from the sample free surface. This novel grain refinement in high-carbon Co-Cr-Mo alloy was attributed to the generation of larger quenching thermal stresses introduced beneath the surface during cyclic solution treatment. The repetitive heating/cooling cycle modifies the surface properties, refines the grain size and leads to uniform dispersion of the secondary carbides. The corrosion resistance of the cyclically solution heat-treated samples was superior as compared to the as-cast one.

The Effect of Solution Time on the Microstructure of A356.2 Aluminum Alloy Provided by Rheocasting and Squeeze Casting

2022 ◽  
Vol 327 ◽  
pp. 189-196
Author(s):  
Le Cheng ◽  
Hong Xing Lu ◽  
Min Luo ◽  
Xing Gang Li ◽  
Wan Peng Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Production Efficiency ◽  
Treatment Process ◽  
Squeeze Casting ◽  
Solution Process ◽  
Solution Treatment ◽  
Solution Time ◽  
Conventional Solution ◽  
Short Time

The evolution of the microstructure of A356.2 alloys prepared by the rheocasting and squeeze casting during solution heat treatment was investigated. In contrast with the conventional solution heat treatment process (3 hours at 540oC), a short time solution treatment process (less than 1 hour at 540oC) is applied in this paper. The results show that the rheocastings require a shorter solution time than the squeeze-castings to obtain spheroidized Si particles. After solution for 10 min, the X-ray diffraction inspection results show that the Mg2Si phase completely is dissolved in both rheocastings and squeeze-castings. However, a small amount of Mg2Si is found at the edge of the Si particle by scanning electron microscope observation. After solution for more than 20 min, the Mg2Si phase is completely dissolved. Fe-rich phases, including AlSiFeMg and AlFeSi, exist throughout the solution process. The developed T6 heat treatment with a short solution time can effectively improve production efficiency and decrease process cost for the rheocasting process. Key words: A356.2 alloy, microstructure, short solution time, rheocasting, squeeze casting

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