The Influence of Composition Segregation to the Microstructure and Mechanical Properties of SA508-3 Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1017-1021 ◽  
Author(s):  
Lu Han Hao ◽  
Ming Yue Sun ◽  
Dian Zhong Li

A large scale ingot was dissected to study the segregation law of the elements. The influence of composition segregation to the microstructure and mechanical properties of SA508-3 steel was studied by the comparison of three positions on the ingot. Two precipitated phases were approved to be alloyed cementite and molybdenum carbide (Mo2C). It has demonstrated that the middle and upper parts of the ingot were almost the same in compositions except for a slightly difference in the carbon content. The upper part with more carbon included has relatively more carbide precipitation after the performance heat treatment. The bottom part of the ingot has the lowest carbon and molybdenum content, while the reduction in the amount of precipitated carbide was not observed. On the contrary, fine needle-like Mo2C are extensively distributed in the matrix of the bottom part besides a variety of coarse cementite rods. And the data of Energy Dispersion Spectrum (EDS) mapping has suggested that precipitation of Mo2C tends to bring the segregation of impurities. Many large inclusions were found in the bottom part of the ingot, which were considered to be the main reason for the strength loss of this area.

2019 ◽  
Vol 38 (2019) ◽  
pp. 404-410 ◽  
Author(s):  
Weijuan Li ◽  
Haijian Xu ◽  
Xiaochun Sha ◽  
Jingsong Meng ◽  
Zhaodong Wang

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.


2010 ◽  
Vol 667-669 ◽  
pp. 457-461
Author(s):  
Wei Guo ◽  
Qu Dong Wang ◽  
Man Ping Liu ◽  
Tao Peng ◽  
Xin Tao Liu ◽  
...  

Cyclic channel die compression (CCDC) of AZ31-1.7 wt.% Si alloy was performed up to 5 passes at 623 K in order to investigate the microstructure and mechanical properties of compressed alloys. The results show that multi-pass CCDC is very effective to refine the matrix grain and Mg2Si phases. After the alloy is processed for 5 passes, the mean grain size decreases from 300 μm of as-cast to 8 μm. Both dendritic and Chinese script type Mg2Si phases break into small polygonal pieces and distribute uniformly in the matrix. The tensile strength increases prominently from 118 MPa to 216 MPa, whereas the hardness of alloy deformed 5 passes only increase by 8.4% compared with as-cast state.


2018 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
Jianlong Liu ◽  
Qingjie Wu ◽  
Hong Yan ◽  
Songgen Zhong ◽  
Zhixiang Huang

The effects of rare earth yttrium (Y) additions and the heat treatment process on the microstructure and mechanical properties of as-cast ADC12 aluminum alloy have been investigated. The results showed that the primary Si crystals were significantly refined from long axis to fibrous or granular when the Y content was 0.2 wt%. Compared to the matrix, the mean area and aspect ratio were decreased by 92% and 75%, respectively. Moreover, the Si and Fe-rich phases were spheroidized and refined with a small average size during the solid solution. It was also noted that the copper-rich phases were dissolved into the matrix. Correspondingly, it was found that after metamorphic and heat treatment the ultimate tensile strength (UTS), elongation, and, hardness increased by 81.9%, 69.7%, and 74.8%, respectively, compared to the matrix. The improved mechanical properties can primarily be attributed to the optimization of the microstructure and the refinement of various phases.


2011 ◽  
Vol 239-242 ◽  
pp. 352-355
Author(s):  
Quan An Li ◽  
Qing Zhang ◽  
Chang Qing Li ◽  
Yao Gui Wang

The effects of 2-12 wt.% Y addition on the microstructure and mechanical properties of as-cast Mg-Y binary alloys have been investigated. The results show that proper content of rare earth Y addition can obviously refine the grains and form high melting point Mg24Y5 phases in the matrix, and improve the microstructure and mechanical properties of the alloys. At room temperature, the optimum combination of ultimate tensile strength and elongation, 195MPa and 7.5%, is obtained in Mg-10 wt.% Y alloy.


1994 ◽  
Vol 364 ◽  
Author(s):  
W. M. Yin ◽  
J. T. Guo ◽  
S. H. Wang ◽  
H. Li ◽  
M. H. Tan ◽  
...  

AbstractThe microstructure and mechanical properties of Ni3Al-based composites reinforced with TiC particles have been investigated. The composites, which contained 2, 6, 10 vol.%TiC particulate reinforcement, were fabricated by solidification processing method. The matrix alloy selected for this study was the advanced nickel-aluminide (Ni-16Al-8Cr-1Zr-0.8Mo-0.04B at.%).The optical micrographs revealed that the carbides in the composites distributed uniformly in the martix and appeared as fairly equiaxed particles. SEM observation showed that the interface between TiC and matrix is quite smooth, sharp and free of any phase. The test results indicated that the hardness was increased with increasing volume fraction of TiC particles at ambient temperature, and the composites exhibited higher hardness after 1100°C × 8h heat treatment. The yield strength has been improved due to reinforcement by the TiC particles at ambient and elevated temperature, but their ductility was reduced obviously. From SEM fractography, it could be seen that tensile failure occurred at the matrix / particulate interface.


2021 ◽  
Vol 40 (1) ◽  
pp. 300-309
Author(s):  
Sheng Huang ◽  
Changrong Li ◽  
Zhiying Li ◽  
Zeyun Zeng ◽  
Yongqiang Zhai ◽  
...  

Abstract HRB500E seismic steel bars are mainly used in high-rise buildings near the seismic zone. The influence of different niobium contents (0–0.023%) on the microstructure and mechanical properties of HRB500E seismic reinforcement was studied. Results showed that the grain size of ferrite was between 3.6 and 8.3 μm when only V was added. Meanwhile, as the niobium content increases, the ferrite particles are further refined. After adding niobium, the grain contribution increased by 9%. The addition of niobium significantly refined the grain size of HRB500E seismic reinforcement. The second-phase nano-elliptic precipitate is NbC. The precipitated phase is dispersed on the grain boundary and the matrix, and the dislocation density on the matrix promotes the precipitation of NbC particles along the dislocation line. The second-phase precipitation of niobium can form an effective pinning effect and then refine the pearlite spacing. The microhardness and the tensile strength also significantly improved. The yield strength increased from 509 to 570 MPa.


2019 ◽  
Vol 1156 ◽  
pp. 10-16
Author(s):  
Yu Chih Tzeng ◽  
Chih Ting Wu

This study investigates how the use of Inconel filler metal 625 affects the microstructure and mechanical properties of gas tungsten arc welded joints of an IN-713LC nickel-based superalloy. Due to their difference in composition, obvious weld beads could be found by X-ray detection. In addition, it was found that the γ' strengthening phase was absent and carbide was present between the matrix and the weld bead during gas tungsten arc welding. These carbides are strongly related to the formation of cracking and weld shrinkage during solidification. The absence of the γ' strengthening phase and the presence of weld shrinkage and cracking led to a decrease in the hardness, tensile strength, and elongation of the welded pieces.


CrystEngComm ◽  
2015 ◽  
Vol 17 (48) ◽  
pp. 9318-9322 ◽  
Author(s):  
Wenna Liu ◽  
Junhong Chen ◽  
Kuo-Chih Chou ◽  
Xinmei Hou

The mechanical properties of dumbbell-shaped fiber-reinforced composites are expected to be improved via enhancing the interface adhesion between the matrix and the fibers from the viewpoint of biomimetics.


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