scholarly journals The Effect of Heat Treatment on the Tribological Properties and Room Temperature Corrosion Behavior of Fe–Cr–Al-Based OPH Alloy

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5465
Author(s):  
Omid Khalaj ◽  
Ehsan Saebnoori ◽  
Hana Jirková ◽  
Ondřej Chocholatý ◽  
Ludmila Kučerová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Room Temperature ◽  
Wear Testing ◽  
Microstructural Properties ◽  
Initial State ◽  
Corrosion Properties ◽  
Fine Microstructure ◽  
Negative Effect

The microstructure, mechanical, tribological, and corrosion properties of Fe–Cr–Al–Y-based oxide-precipitation-hardened (OPH) alloy at room temperature are presented. Two OPH alloys with a composition of 0.72Fe–0.15Cr–0.06Al–0.03Mo–0.01Ta–0.02Y2O3 and 0.03Y2O3 (wt.%) were prepared by mechanical alloying with different milling times. After consolidation by hot rolling, the alloys presented a very fine microstructure with a grain size of approximately 180 nm. Such a structure is relatively brittle, and its mechanical properties are enhanced by heat treatment. Annealing was performed at three temperatures (1000 °C, 1100 °C, and 1200 °C), with a holding time from 1 to 20 h. Tensile testing, wear testing, and corrosion testing were performed to evaluate the effect of heat treatment on the behavior and microstructural properties. The grain size increased almost 10 times by heat treatment, which influenced the mechanical properties. The ultimate tensile strength increased up to 300% more compared to the initial state. On the other hand, heat treatment has a negative effect on corrosion and wear resistance.

Grain Size Dependence of Tensile Properties in Cu-Sn Thin Foils (Experimental Study)

2015 ◽  
Vol 736 ◽  
pp. 19-23
Author(s):  
Taek Kyun Jung ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Study ◽  
Grain Size ◽  
Yield Strength ◽  
Room Temperature ◽  
Size Dependence ◽  
Yield Drop ◽  
Thin Foils ◽  
Vacuum Atmosphere

This study was carried out to investigate the effects of grain size on mechanical properties in Cu-Sn foil with a thickness of 30 um. The grain size was varied from approximately 7 um to 50 um using heat treatment at 773 K for 2 h to 24 h in a vacuum atmosphere. Tensile test was carried out at room temperature with strain rate of 1mm/min. Typical yield drop phenomenon was observed. Mechanical properties were found to be strongly affected by microstructural features including grain size. The yield strength and tensile strength gradually decreased with increasing the grain size. The strain to fracture also decreased by grain growth. These results could be explained by not only the grain size dependence of yield strength but also the ratio of thickness to grain size dependence of yield strength.

Effect of Twice Stablizing Heat Treatment on the Properties of 347H Stainless Steel

2021 ◽  
Vol 904 ◽  
pp. 82-87
Author(s):  
Zhi Juan Zhao ◽  
Xue Tao Zhang ◽  
Qiang Dai ◽  
Yan Rong ◽  
Jing Miao Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Room Temperature ◽  
Corrosion Properties ◽  
Double Ring ◽  
Microstructure Observation ◽  
Sensitization Process ◽  
Sensitization Behavior ◽  
Test Impact

In this study, the mechanical properties and intergranular corrosion properties of 347H austenitic stainless steel were studied by tensile test, impact test, double-ring electrochemical potentiodynamic reactivation test (DL-EPR) and microstructure observation in three states of solution, primary and twice stabilized state. Results showed that the key mechanical properties of 347H stainless steel under three different conditions had little change, and the mechanical properties at room temperature were not affected by the stabilizing heat treatment. After 12h of sensitization, the solution material showed obvious sensitization behavior, and the Ir/Ia index exceeded 0.3, indicating that the material entered the range of complete sensitization. Both primary and twice stabilizing heat treatment can significantly reduce the occurrence time of sensitization and prevent the sensitization process. However, the stabilizing heat treatment cannot completely prevent the material sensitization, and it must be combined with other methods .

The Study of Type Twin Annealing in High Mn Steel

2011 ◽  
Vol 148-149 ◽  
pp. 1085-1088
Author(s):  
Gholam Reza Razavi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Room Temperature ◽  
Twip Steel ◽  
Manganese Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
Twip Steels ◽  
Mn Steel

TWIP steels are high manganese steel (Mn: 17% - 35%) which are used for shaping car bodies. The structure of this kind of steels remains austenite even in room temperature. Due to low SFE (Stacking Fault Energy) twinning of grains is governing reformation mechanism in this kind of steels which strengthen TWIP steel. Regarding heat treatment influences on mechanical properties of TWIP steels, in this paper we discuss twinning phenomenon resulting from this kind of treatment. For this, following casting and hot rolling processes, we anneal the steel at 1100°C and different time cycles and study its microstructure using light microscope. The results showed that with decreasing grain size the number of twin annealing added And four types of annealing twin in the microstructure, in the end they all become one twin and then turn into grain.

Characterization of Co-Cr-Mo Alloys Used in HIP Implant Articulating Surfaces

1996 ◽  
Vol 441 ◽  
Author(s):  
R. Varano ◽  
J. D. Bobyn ◽  
S. Yue
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Boundary ◽  
Room Temperature ◽  
Volume Fraction ◽  
Face Centered Cubic ◽  
Hip Implant ◽  
Fine Microstructure ◽  
Face Centered

AbstractThe microstructure, crystallography and mechanical properties of a wrought (ASTM F-1537) Co-Cr- Mo hip implant alloy were studied in this work. The effects of carbon content, heat treatment and room temperature compression on the above characteristics were also analyzed. Metallography of the asreceived material revealed the presence of ‘twins’ in a relatively fine microstructure with some randomly distributed grain boundary carbides. Heat treatment of the specimens produced a coarser microstructure, more uniformly distributed grain boundary carbides and annealing twins. Neutron diffraction of the specimens, which were deformed at room temperature, exhibited an increase in the volume fraction of the more stable Co-hexagonal closed-packed (HCP) crystal structure, due to a strain-induced transformation (SIT) from the metastable Co-face-centered cubic (FCC) crystal structure. It was also seen that the higher C specimens, as well as the heat treated specimens, possessed a lower volume fraction of the HCP phase. It was found, through shear punch testing, that the deformed specimens exhibited higher mechanical properties without any significant losses to the ductility of the material.

scholarly journals The Effect of Pre-Annealing on the Evolution of the Microstructure and Mechanical Behavior of Aluminum Processed by a Novel SPD Method

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2361 ◽  
Author(s):  
Alexander P. Zhilyaev ◽  
Mario J. Torres ◽  
Homero D. Cadena ◽  
Sandra L. Rodriguez ◽  
Jessica Calvo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
High Temperature ◽  
Room Temperature ◽  
Pure Aluminum ◽  
Continuous Process ◽  
Tensile Tests ◽  
New Method ◽  
Slow Cooling

A novel continuous process of severe plastic deformation (SPD) named continuous close die forging (CCDF) is presented. The CCDF process combines all favorite advances of multidirectional forging and other SPD methods, and it can be easily scaled up for industrial use. Keeping constant both the cross section and the length of the sample, the new method promotes a refinement of the microstructure. The grain refinement and mechanical properties of commercially pure aluminum (AA1050) were studied as a function of the number of CCDF repetitive passes and the previous conditioning heat treatment. In particular, two different pre-annealing treatments were applied. The first one consisted of a reheating to 623 K (350 °C) for 1 h aimed at eliminating the effect of the deformation applied during the bar extrusion. The second pre-annealing consisted on a reheating to 903 K (630 °C) for 48 h plus cooling down to 573 K (300 °C) at 66 K/h. At this latter temperature, the material remained for 3 h prior to a final cooling to room temperature within the furnace, i.e., slow cooling rate. This treatment aimed at increasing the elongation and formability of the material. No visible cracking was detected in the workpiece of AA1050 processed up to 16 passes at room temperature after the first conditioning heat treatment, and 24 passes were able to be applied when the material was subjected to the second heat treatment. After processing through 16 passes for the low temperature pre-annealed samples, the microstructure was refined down to a mean grain size of 0.82 µm and the grain size was further reduced to 0.72 µm after 24 passes, applied after the high temperature heat treatment. Tensile tests showed the best mechanical properties after the high temperature pre-annealing and 24 passes of the novel CCDF method. A yield strength and ultimate tensile strength of 180 and 226 MPa, respectively, were obtained. Elongation to fracture was 18%. The microstructure and grain boundary nature are discussed in relation to the mechanical properties attained by the current ultrafine-grained (UFG) AA1050 processed by this new method.

scholarly journals Grain Size Evolution and Mechanical Properties of Nb, V–Nb, and Ti–Nb Boron Type S1100QL Steels

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 492
Author(s):  
Jan Foder ◽  
Jaka Burja ◽  
Grega Klančnik
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Hot Forging ◽  
Size Control ◽  
High Strength ◽  
Fatigue Properties ◽  
Titanium Addition ◽  
Austenite Grain Size ◽  
Size Evolution

Titanium additions are often used for boron factor and primary austenite grain size control in boron high- and ultra-high-strength alloys. Due to the risk of formation of coarse TiN during solidification the addition of titanium is limited in respect to nitrogen. The risk of coarse nitrides working as non-metallic inclusions formed in the last solidification front can degrade fatigue properties and weldability of the final product. In the presented study three microalloying systems with minor additions were tested, two without any titanium addition, to evaluate grain size evolution and mechanical properties with pre-defined as-cast, hot forging, hot rolling, and off-line heat-treatment strategy to meet demands for S1100QL steel. Microstructure evolution from hot-forged to final martensitic microstructure was observed, continuous cooling transformation diagrams of non-deformed austenite were constructed for off-line heat treatment, and the mechanical properties of Nb and V–Nb were compared to Ti–Nb microalloying system with a limited titanium addition. Using the parameters in the laboratory environment all three micro-alloying systems can provide needed mechanical properties, especially the Ti–Nb system can be successfully replaced with V–Nb having the highest response in tensile properties and still obtaining satisfying toughness of 27 J at –40 °C using Charpy V-notch samples.

scholarly journals Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Testing Machine ◽  
Dendritic Structure ◽  
Grain Refiner ◽  
Corrosion Properties ◽  
Average Grain Size ◽  
Structural Applications ◽  
Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Selective Laser Melted TiAl6V4 Alloy

2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Base Alloy ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Treatment Procedures

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.

Effect of Post Weld Heat Treatment on Fusion and Heat Affected Zone Microstructure and Mechanical Properties of Inconel X-750 Welds

2011 ◽  
Vol 214 ◽  
pp. 108-112 ◽  
Author(s):  
Prachya Peasura ◽  
Bovornchok Poopat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Grain Boundary ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Aging Temperature ◽  
Post Weld Heat Treatment ◽  
High Aging Temperature ◽  
Zone Microstructure

The Inconel X-750 indicates good hot corrosion resistance, high stability and strength at high temperatures and for this reason the alloy is used in manufacturing of gas turbine hot components. The objective of this research was study the effect of post weld heat treatment (PWHT) on fusion zone and heat affected zone microstructure and mechanical properties of Inconel X-750 weld. After welding, samples were solutionized at 1500 0C. Various aging temperature and times were studied. The results show that aging temperature and time during PWHT can greatly affect microstructure and hardness in fusion zone and heat affected zone. As high aging temperature was used, the grain size also increased and M23C6 at the grain boundary decreased. This can result in decreased of hardness. Moreover excessive aging temperature can result in increasing MC carbide intensity in parent phase (austenite). It can also be observed that M23C6 at the grain boundary decreased due to high aging temperature. This resulted in decreasing of hardness of weld metal and heat affected zone. Experimental results showed that the aging temperature 705 0C aging time of 24 hours provided smaller grain size, suitable size and intensity of MC carbide resulting in higher hardness both in weld metal and HAZ.

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