Deformation Behaviors of Non-Metallic Inclusion in FGH96 Superalloy during Different Plastic Processes

2012 ◽  
Vol 538-541 ◽  
pp. 1187-1191
Author(s):  
Min Cong Zhang ◽  
Chen Yi Liu ◽  
Shu Yun Wang

The non-metallic inclusions in FGH96 superalloy during different plastic processes were studied. The results show that SiO2 react with aluminum and titanium in FGH96 superalloy and the reaction zone is formed in the interface between SiO2 and alloy, whereas Al2O3 react with no elements in FGH96 superalloy and the transition zone between them is mechanical combination during the plastic processes. In addition the sizes of non-metallic inclusions increase in the direction perpendicular to deformation during isothermal forging process. The non-metallic inclusions are pulled into a discontinuous line in extrusion direction and areas of non-metallic inclusions in each direction are constricted during extrusion process. The non-metallic inclusions of FGH96 superalloy is conditioned by the state of the as-extrusion inclusions during extrusion+isothermal forging process. In summary, extrusion process with large extrusion ratio can break the non-metallic inclusions in FGH96 alloy effectively and improve forging quality.

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 207
Author(s):  
Chul Jin

A process comprising a hot extrusion process and a warm forging process was designed to form an umbrella-shaped aluminum structural component with a high degree of difficulty for the plastic forming method. A circular cylindrical part was extruded with a hot extrusion process, and then an embossing part was produced with a warm forging process. The formability and the maximum load required for forming were then determined using a forming analysis program. The hot extrusion process was executed at 450 °C under the extrusion speed at 6 mm/s, while the warm forging process was executed at 260 °C under the forging speed at 150 mm/s. The simulation results showed that the load required for hot extrusion was 1019 ton, while the load required for the warm forging was 534 ton. The umbrella-shaped part was manufactured by using a 1600 ton capacity press. The graphite lubricant was coated on the mold as well as the material. A forming experiment was performed under the same condition with the simulation condition. The portion where extrusion was done became elliptical with the α-Al phase elongated towards extrusion direction. Whereas, the α-Al phase became circular in the forged portion. The tensile strength value was found as 345 MPa, while elongation rate was 12%. Meanwhile, Vickers hardness value at the extruded portion was 105 HV, and it was 110 HV at the forged portion.


2013 ◽  
Vol 747-748 ◽  
pp. 526-534 ◽  
Author(s):  
Xiao Feng Wang ◽  
Xiao Ming Zhou ◽  
Jie Yang ◽  
Jin Wen Zou ◽  
Wu Xiang Wang

According to the defects of powder metallurgy superalloy, especially the influence and damage of inclusions on properties of disk, the deviation between nondestructive testing and metallographic testing of inclusions in FGH96 alloy isothermal forging disk was investigated. Meanwhile, the types and deformation mechanism of inclusions were studied. The results showed that the buried depth tested by metallographic detection was less 67-180μm than nondestructive testing. The size of inclusions with metallographic detection was less about 18-50μm than nondestructive testing. The major types of inclusions in practical disk were Al2O3 and Al2O3-SiO2, the inclusions run through several grains, no matter Al2O3 or Al2O3-SiO2. The Al2O3 inclusion and matrix was purely mechanical bonding, but the Al2O3-SiO2 had reaction zone. There was remarkable effect of extrusion process on crushing and dispersing Al2O3 inclusion, but which was unremarkable for Al2O3-SiO2.


2007 ◽  
Vol 26-28 ◽  
pp. 367-371
Author(s):  
Hong Zhen Guo ◽  
Zhang Long Zhao ◽  
Bin Wang ◽  
Ze Kun Yao ◽  
Ying Ying Liu

In this paper the effect of isothermal forging process parameters on the microstructure and the mechanical properties of TA15 titanium alloy was researched. The results of the tests indicate that, in the range of temperature of 850 °C~980 °C and deformation degree of 20%~60%, with the increase of temperature or deformation, as the reinforcement of deformation recrystallization, the primary α-phase tends to the spherical shape and secondary α-phase transforms from the acicular shape to fine and spherical shape with disperse distribution, which enhance the tensile properties at room and high temperature. With the increment of forging times, the spheroidization of primary α-phase aggrandizes and secondary α-phase transforms from spherical and acicular shape to wide strip shape, which decrease the tensile properties at room and high temperature. The preferable isothermal forging process parameters are temperature of 980 °C, deformation degree of 60%, and few forging times.


2013 ◽  
Vol 347-350 ◽  
pp. 1171-1175 ◽  
Author(s):  
Bin Wang ◽  
Hong Mei Hu ◽  
Cui Zhou

The transverse properties were inferior to the longitudinal properties for the existence of banded structure in 20G steel. In order to eliminate the banded structure and improve the transverse performance of 20G steel, different heat treatment processes were adopted. The results showed that conventional normalizing could reduce the banded structure and refine the grain sizes. When 20G was heated with 10°C/min heating rated and then held at 920°C for 2h, the banded structure in the steel was almost eliminated and the microstructure was homogeneous with fine grain size, the strength increased by 14%. The non-metallic inclusion and carbide in the microstructure leaded to stress concentration and separation with the base metal. To some extent, heat treatment can improve the distribution and form of non-metallic inclusions.


Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Yushi Qi ◽  
Heng Wang ◽  
Lili Chen ◽  
Hongming Zhang ◽  
Gang Chen ◽  
...  

A ZK61-Y magnesium (Mg) alloy wheel hub was prepared via liquid forging—isothermal forging process. The effects of Y-element contents on the microstructure and mechanical properties of liquid forging blanks were investigated. The formation order of the second phase was I-phase (Mg3Zn6Y) → W-phase (Mg3Zn3Y2) → Z-phase (Mg12ZnY) with the increase of the Y-element content. Meanwhile, the I-phase and Z-phase formed in the liquid forging process were beneficial to the grain refinement. The numerical simulation of the isothermal forging process was carried out to analyze the effects of forming temperature on the temperature and stress field in the forming parts using the software Deform-3D. Isothermal forging experiments and post heat treatments were conducted. The influence of isothermal forging temperature, heat treatment temperature and preservation time on the microstructure and mechanical properties of the forming parts were also studied. The dynamic recrystallization (DRX), second-phase hardening, and work hardening account for the improvement of properties after the isothermal forging process. The forming part forged at 380 °C displayed the outstanding properties. The elongation, yield strength, and ultimate tensile strength were 18.5%, 150 MPa and 315 MPa, respectively. The samples displayed an increased elongation and decreased strength after heat treatments. The 520 °C—1 h sample possessed the best mechanical properties, the elongation was 25.5%, the yield stress was 125 MPa and the ultimate tensile strength was 282 MPa. This can be ascribed to the recrystallization and the elimination of working hardening. Meanwhile, the second phase transformation (I-phase → W-phase → Mg2Y + MgZn2), dissolution, and decomposition can be observed, as well.


2012 ◽  
Vol 184-185 ◽  
pp. 1255-1258
Author(s):  
Zhuang Li ◽  
Di Wu ◽  
Wei Lv

The important factors that affect the formability of the cold forging steel are its surface quality and internal defects. The cracking phenomenon was taken place during cold forging of ML25Mn steel. In this study, microstructural analyses were made on around the cracked regions of the steel. The reason of cracking, which occurred during cold forging for ML25Mn steel, was investigated based on SEM observation in detail. The results have shown that the crack forming during cold forging process is not related to the chemical composition for ML25Mn steel. Cracking is not resulted from high hardness of the steel rods. There are some non-metallic inclusions in the matrix of ML25Mn steel, and the film-like inclusions are composed of MnS, CaS and complex oxides containing Mg, Al, Mn, Fe, S, Ca and O. The formation of non-metallic inclusions is the result of the deoxidation and the solidification during smelting and casting of steel.


2014 ◽  
Vol 912-914 ◽  
pp. 605-608 ◽  
Author(s):  
Xuan Rong Xin ◽  
Ding Xu ◽  
Cheng Song He ◽  
Xin Cheng Liu

Aimed at the present domestic problems in the forging process of claw pole, such as insufficient corner filling, excessive forming force and short life of dies. On the basis of the analyzing in the claw pole, a new process named the closed hot die forging, direct extrusion process of claw pole is constituted. The numerical simulation using DEFORM-3D and the special mould are used in the forging experiment in order to check the new process. The results show that, new technology has greatly reduced the forming force, thereby reducing the production processes and improving the life of dies for mass production.


2012 ◽  
Vol 509 ◽  
pp. 68-74
Author(s):  
Xiu Li Hou ◽  
Xu Sun ◽  
Li Min Wang ◽  
Zhan Yi Cao

In present work, the Mg−Gd−Nd−Y−Zn alloy sheets were prepared by hot extrusion technique. The microstructure, texture and mechanical properties of the extruded alloy were investigated. After hot extrusion, the alloy reveals a greatly refined microstructure due to the dynamic recrystallization. The coarse eutectic phases were crushed into small particles during extrusion process, which brings a promotion of grain refinement. A weak basal fiber texture was obtained in the as-extruded alloy owing to the influence of RE (rare earth) alloying elements. The as-extruded alloy exhibits mechanical anisotropy that the strengths and elongations in the extrusion direction are both higher than those in the transverse direction. And this behavior does not change with increasing temperature. It results from the weak texture and the distribution of eutectic phase particles in the alloy sheet. Through isothermal aging treatment, significant strengthening is achieved in the peak-aged alloy, and the mechanical anisotropy still exists.


2006 ◽  
Vol 503-504 ◽  
pp. 775-780 ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Tadayoshi Tsukeda ◽  
Ken Saito ◽  
Yoshihito Kawamura

In order to make the effect of processing clear, AM50A magnesium casting alloys were extruded at various extrusion conditions such as extrusion temperature and extrusion ratio. The mechanical properties of AM50A alloy increased with decreasing extrusion temperature. Tensile yield strength and tensile strength of extruded AM50A alloy were 389MPa and 420MPa respectively when the extrusion temperature was 348K. The microstructure of the extruded magnesium alloy showed large grains stretched to the extrusion direction and fine recrystallized grains. Decreased extrusion temperature resulted in improved strength and decreased elongation with increasing of the degree of work hardens and extrusion force. When the extrusion ratio is high, improvement of strength is prevented by rycrystallization and it was observed as crystal orientation by XRD. The elongation of the extrusion increased with the recrystallization of grains. Every magnesium alloy extruded at low temperature has high strength.


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