Experimental Study on Transformation Plasticity in Terms of Three-Point Bending System

2014 ◽  
Vol 626 ◽  
pp. 408-413 ◽  
Author(s):  
M. Arif Hamdam ◽  
Shigeru Nagaki ◽  
Kenichi Oshita
Keyword(s):  
Phase Transformation ◽  
Martensite Phase ◽  
The Other ◽  
Maximum Deflection ◽  
Transformation Plasticity ◽  
Three Point Bending ◽  
Bending Stresses ◽  
Simple Support ◽  
Plasticity Coefficient ◽  
Forced Cooling

Three-point bending system with one end simple support and the other end fix support has been proposed to analyze the transformation plasticity (TP) behavior and obtain transformation plasticity coefficient. In this investigation two types of materials SCM440 steel and S45C steel have been studied. The specimens were heated to austenite temperature and the temperature kept constant for several minutes, then cooling and loading processes were performed. Austenite to martensite phase transformation with forced cooling for SCM440 steel and austenite to pearlite phase transformation with natural cooling for S45C steel due to bending stresses have been occurred. The deflections of specimen were measured during loading process. By obtaining the maximum deflection due to transformation plasticity, the transformation plasticity coefficient was determined.

Experimental Study on Nitrogen-Spray Water Quenching for 9SiCr

2012 ◽  
Vol 430-432 ◽  
pp. 365-368
Author(s):  
Bao Dong Shao ◽  
Li Feng Wang ◽  
He Ming Cheng ◽  
Rui Jie Wang ◽  
Jian Yun Li ◽  
...  
Keyword(s):  
Residual Stress ◽  
Experimental Study ◽  
Phase Transformation ◽  
Alloy Steel ◽  
Martensite Phase ◽  
The Other ◽  
Water Quenching ◽  
Cooling Curve ◽  
Quenching Medium ◽  
The One

Alloy steel 9SiCr is quenched by a certain proportion of mixture gas of nitrogen and spray water at atmosphere, and the continual cooling curve during quenching is determined, the rigidity of quenched workpiece is measured and the metallographic map is captured. The results show that it can improve the cooling effect of quenching medium on the one hand; on the other hand, it can decrease the deformation and residual stress of workpieces. The results show that the rigidity of quenched workpiece is about 62 (HRC), which is corresponding with the rigidity after oil quenching. Martensite phase transformation occurs at the end of quenching that can be seen from the metallographic map.

Influence of material parameters on 2D-martensitic transformation based on the phase-field finite-element method

2019 ◽  
Vol 116 (6) ◽  
pp. 614
Author(s):  
Li Chang ◽  
Gao Jingxiang ◽  
Zhang Dacheng ◽  
Chen Zhengwei ◽  
Han Xing
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Phase Field ◽  
Martensite Transformation ◽  
Transformation Process ◽  
Martensite Phase ◽  
Phase Field Method ◽  
Element Method

Obtaining an accurate microscopic representation of the martensitic transformation process is key to realizing the best performance of materials and is of great significance in the field of material design. Due to the martensite phase transformation is rapidly, the current experimental is hard to capture all the information in the Martensite phase transformation process. Combining the phase-field method with the finite-element method, a model of martensitic transformation from a metastable state to a steady state is established. The law of a single martensite nucleus during martensitic transformation is accurately described. By changing the key materials that affect martensite transformation and the phase-field parameters, the effects of the parameters on the single martensitic nucleation process are obtained. This study provides an important theoretical basis for effectively revealing the essence of martensite transformation and can determine effective ways to influence martensite transformation, obtain the optimal parameters and improve the mechanical properties of such materials.

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

Surface Effect in a Metastable β Ti-Nb-Sn Alloy

2021 ◽  
Vol 1035 ◽  
pp. 562-567
Author(s):  
Li Chun Qi ◽  
Wen Xiao Qu ◽  
Yong Qi Zhu ◽  
Qing Liu
Keyword(s):  
Titanium Alloys ◽  
Orientation Relationship ◽  
Surface Effect ◽  
Phase Region ◽  
Martensite Phase ◽  
The Other ◽  
Β Phase ◽  
Ω Phase

The phase compositions of surface and interior in Ti-32Nb-4Sn metastable b alloy were investigated. It was found that this alloy exhibits surface effect significantly different from the effects reported in Ti-10V-2Fe-3Al, Ti-22Nb-9Zr and the other titanium alloys. The surface of Ti-32Nb-4Sn specimen quenched from single b phase region was characterized by dominant b phase and a few of α″ and ω phase. While in the interior of the alloy, a large amount of α² martensite phase was observed in addition to b phase The orientation relationship between the α″ martensite and β phase is (110)β∥(002)α″, (020)β∥(022)α″ and [001]β∥[100]α″.

Diffraction Analysis at the Meso and Micro Scale During the Mechanically Induced Martensite Phase Transformation

ICOMAT ◽  
2013 ◽  
pp. 255-262
Author(s):  
B. Malard ◽  
G. Geandier ◽  
J. Wright ◽  
T. Buslaps ◽  
S. Berveiller ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Diffraction Analysis ◽  
Martensite Phase ◽  
Micro Scale

scholarly journals The Effect of Drawing Deformation Rate Induced Inhomogeneous Local Distortion on Phase Transformation of 304H Stainless Wire

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1304
Author(s):  
Qinhua Xu ◽  
Zhixian Peng ◽  
Jianxin Zhu ◽  
Mingyang Li ◽  
Yong Zong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Heat Generation ◽  
Martensite Transformation ◽  
Local Strain ◽  
Cold Drawing ◽  
Element Distribution ◽  
Martensite Phase ◽  
Single Strain ◽  
Area Reduction

The micro/macro magnetic properties, local element distribution, martensite transformation, and mechanical properties of 304H stainless wires are determined for two cold drawing chains. Finite element simulations are used to analyse the local strain and heat generation. The results show that there is obvious inhomogeneity in the magnetic properties, strain/stress relationship, and strain-induced heat within the drawn wires. Comparing wires with the same total strain, a larger area reduction of previous drawing processes contributes to a higher volume of the martensite phase, while a smaller area reduction of the first process results in an inhibited phase transformation. A higher single strain in the first drawing process leads to additional heat generation at the subsurface of the wire, which would eventually retard the martensite transformation. The inhomogeneous deformation-induced differences in the grain size affect the stability of austenite and transform the final martensite.

Study on Microstructure of Quenched Martensite in W6Mo5Cr4V2 Steel

2011 ◽  
Vol 295-297 ◽  
pp. 175-178
Author(s):  
Yun Ping Ji ◽  
Zong Chang Liu ◽  
Hui Ping Ren
Keyword(s):  
Phase Transformation ◽  
Small Area ◽  
Martensite Phase ◽  
Stacking Fault ◽  
Plate Martensite ◽  
Twin Crystal ◽  
Transmission Electron ◽  
Starting Point ◽  
Austenite Grains ◽  
The Difference

The microstructure and the formation mechanism of martensite in W6Mo5Cr4V2 steel was studied by metallographic microscope and JEM-2100 transmission electron microscope after the samples were austenized between the temperatures of Ac1~Accm and then quenched. The results show that When heating W6Mo5Cr4V2 steel samples between the temperatures of Ac1~Accm and then quenching, the cryptocrystalline martensite will be obtained. The cryptocrystalline martensite is plate martensite actually. It is considered that the formation cause of the cryptocrystal martensite is extremely inhomogeneous chemical composition in the austenite grains and the difference of martensite starting point (Ms point) of every small area in austenite grains. Besides the high-density dislocation and the fine twin crystal, the substructure of the cryptocrystalline martensite includes the superfine stacking fault. The stacking fault is caused by the stacking misarrangement during the crystal lattice reconstruction of martensite phase transformation. The midrib exists in the cryptocrystal martensite of W6Mo5Cr4V2 steel, which is composed of the fine twin crystal plates. The shear mechanism can not account for the formation of the martensite midrib.

The Study of Ultrasonic Dynamic Elastic Modulus of TiNiFe Shape Memory Alloy in Heating Process

2009 ◽  
Vol 79-82 ◽  
pp. 1699-1702
Author(s):  
Xiao Peng Gao ◽  
Fu Shun Liu
Keyword(s):  
Phase Transformation ◽  
Elastic Modulus ◽  
Test Temperature ◽  
Martensite Transformation ◽  
Martensite Phase ◽  
Austenite Phase ◽  
Dynamic Elastic Modulus ◽  
Heating Process ◽  
Static Tensile ◽  
Tensile Elastic Modulus

The phase transformation characteristics, the dynamic elastic modulus and the static tensile elastic modulus of Ti50Ni47.5Fe2.5 alloy were investigated. It is found that, the two mutations in the dynamic elastic modulus is caused by reverse martensite phase transformation and austenite phase transformation respectively; Static tensile test can not reflect the intrinsic elastic modulus when the test temperature is close to martensite transformation temperature(Ms). The static elastic modulus and the dynamic elastic modulus have the same trend when the test temperature is enough higher than Ms.

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