Reverse Transformation Behavior Induced by Shot-Peening for SUS410S Martensitic Stainless Steel

2016 ◽  
Vol 879 ◽  
pp. 2003-2007
Author(s):  
Nagomi Tsuboi ◽  
Serika Higa ◽  
Hisashi Sato ◽  
Yoshimi Watanabe
Keyword(s):  
Stainless Steel ◽  
Shear Strain ◽  
Shot Peening ◽  
Martensitic Stainless Steel ◽  
Volume Fraction ◽  
Martensite Phase ◽  
Reverse Transformation ◽  
Transformation Behavior ◽  
Thermally Induced ◽  
Large Shear Strain

Reverse transformation behavior of thermally-induced martensite phase (α’) in martensitic stainless steel by the shot-peening is investigated. It is found that volume fraction of austenite phase (γ) on the peened surface is increased by the shot-peening under elevated temperature. This means that reverse transformation from thermally-induced α’ to γ can be induced by the shot-peening. Moreover, with decreasing the distance between blast nozzle and specimen (blast distance), the reverse transformation occurs more remarkably. This is because that larger shear strain can be induced by the shot-peening with shorter blast distance. Furthermore, thickness of the deformation-induced layer becomes larger as the blast distance decreases. It can be concluded that the reverse transformation in SUS410S with thermally-induced α’ occurs by large shear strain during the shot-peening.

Effects of Peening Direction on Reverse Transformation Induced by Shot-Peening for Fe-33%Ni Alloy

2021 ◽  
Vol 1016 ◽  
pp. 1252-1257
Author(s):  
Hisashi Sato ◽  
Takuto Tominaga ◽  
Tadachika Chiba ◽  
Tomokazu Moritani ◽  
Yoshimi Watanabe
Keyword(s):  
Phase Transformation ◽  
Compressive Stress ◽  
Shot Peening ◽  
Transformation Temperature ◽  
Volume Fraction ◽  
Residual Compressive Stress ◽  
Reverse Transformation ◽  
Phase Transformation Temperature ◽  
Transformation Behavior ◽  
Ni Alloy

Effects of peening direction on the reverse transformation induced by the shot-peening for the Fe-33 mass%Ni alloy with large amount of martensite (α’) are investigated. When the angle between the peened surface and the peening direction (Hereafter, peening angle) is 90 o, the reverse transformation occurs and subsequently martensitic transformation is induced by the shot-peening. On the other hand, in case of the peening angle of 30 o, only reverse transformation occurs. Furthermore, the volume fraction of austenite (γ) in the specimen after the shot-peening increases as the peening angle decreases. This means that the reverse transformation induced by the shot-peening is enhanced by decreasing the peening angle. Moreover, residual compressive stress around the peened surface increases as the peening angle decreases. Since the hydrostatic compressive stress decreases phase transformation temperature, the phase transformation temperature around the peened surface would be decreased by the shot-peening. Therefore, the reverse transformation behavior depending on the peening angle can be explained by the residual compressive stress due to the shot-peening.

Transformation/Deformation Behavior and its Constitutive Equation for Ti-Ni-Cu Shape Memory Alloy

2008 ◽  
Vol 59 ◽  
pp. 129-134
Author(s):  
Yuji Takeda ◽  
Takaei Yamamoto ◽  
M. Uegaki ◽  
Hiroki Cho ◽  
Toshio Sakuma ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Constitutive Equation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Constitutive Equations ◽  
Deformation Behavior ◽  
Volume Fraction ◽  
Transformation Process ◽  
Reverse Transformation ◽  
Transformation Behavior

This paper describes the transformation and deformation behavior and its constitutive equation for Ti-41.7Ni-8.5Cu (at%) shape memory alloy. Plastic deformation after pre-deformation is investigated using the volume fraction of slip-deformed martensite. New kinetics and constitutive equations are proposed for the reverse transformation process. The material constants in the proposed equationa are determined from the results of tensile and heating/cooling tests of Ti-41.7Ni-8.5Cu (at%) shape memory alloy. The calculated results describe well the deformation and transformation behavior affected by pre-strain.

scholarly journals Role of Nb in 13Cr super-martensitic stainless steel

2013 ◽  
Vol 66 (2) ◽  
pp. 179-185 ◽  
Author(s):  
Xiaoping Ma ◽  
Cheng Zhou ◽  
Lijun Wang ◽  
Chunming Liu ◽  
Sundaresa Subramanian ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Volume Fraction ◽  
Steel Sample ◽  
Strength Properties ◽  
Stainless Steel Sample ◽  
Precipitate Morphology ◽  
Super Martensitic Stainless Steel ◽  
Microalloying Elements

The effect of Nb microalloying on structure and physical properties of quenched and tempered 13%Cr martensitic stainless steel was investigated. Excellent strength and adequate toughness properties were obtained by 0.10 wt% Nb addition to low interstitial (N 0.01wt%, C < 0.02wt%) steel. The effect of Nb in 13%Cr steels with high N content was also studied in a commercial martensitic stainless steel sample containing higher levels of N and also alloyed with V. The microstructure, precipitate morphology and dispersion and volume fraction of reverse austenite were characterized. The strength properties obtained in the steel with 0.10%Nb are significantly higher than those of the V-containing steel. The study shows that whereas amount, size and dispersion of precipitates of microalloying elements contribute to enhanced strength, the optimum volume fraction of reverse austenite formed contributes to enhanced ductility and toughness properties. More importantly, high Nb additions to low N -13%Cr-1%Mo steel are found to improve significantly resistance against pitting corrosion significantly.

Effect of Equal Channel Angular Pressing on the Microstructure and Mechanical Properties of AISI Type 304 Austenitic Stainless Steel

2013 ◽  
Vol 829 ◽  
pp. 86-90 ◽  
Author(s):  
Mohsen Toofaninejad ◽  
Mahmoud Nili Ahmadabadi
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Equal Channel Angular Pressing ◽  
Volume Fraction ◽  
Martensite Phase ◽  
304 Stainless Steel ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Aisi Type ◽  
Type 304

The present paper describes the effect of severe plastic deformation on the microstructure and mechanical properties of AISI type 304 stainless steel by equal channel angular pressing (ECAP) at room temperature. The strain-induced martensitic transformation occurred in the specimens, and martensite phase increased with increasing strain up to 42% for three passes of ECAP. X ray diffraction was used to identify the strain-induced martensite phase and its volume fraction. The martensite phase, mechanical twins and micro hardness have increased with increasing passes of ECAP. Microstructures of specimens show that with increasing strain, subgrains less than microns are susceptible to be created by fragmentation of twins.

A Shear Strain Route Dependency of Martensite Formation in 316L Stainless Steel

2015 ◽  
Vol 21 (3) ◽  
pp. 582-587 ◽  
Author(s):  
Suk Hoon Kang ◽  
Tae Kyu Kim ◽  
Jinsung Jang ◽  
Kyu Hwan Oh
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Shear Strain ◽  
Martensite Phase ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Strain Induced Martensite ◽  
316L Austenitic Stainless Steel ◽  
Electron Back Scattered Diffraction

AbstractIn this study, the effect of simple shearing on microstructure evolution and mechanical properties of 316L austenitic stainless steel were investigated. Two different shear strain routes were obtained by twisting cylindrical specimens in the forward and backward directions. The strain-induced martensite phase was effectively obtained by alteration of the routes. Formation of the martensite phase clearly resulted in significant hardening of the steel. Grain-size reduction and strain-induced martensitic transformation within the deformed structures of the strained specimens were characterized by scanning electron microscopy – electron back-scattered diffraction, X-ray diffraction, and the TEM-ASTAR (transmission electron microscopy – analytical scanning transmission atomic resolution, automatic crystal orientation/phase mapping for TEM) system. Significant numbers of twin networks were formed by alteration of the shear strain routes, and the martensite phases were nucleated at the twin interfaces.

Effect of Thermal Cycling on Transformation Behavior of Ti–24Nb–1Mo Alloy (at.%)

2020 ◽  
Vol 20 (11) ◽  
pp. 6792-6796
Author(s):  
Jin-Hwan Lim ◽  
Mi-Seon Choi ◽  
Tae-Hyun Nam
Keyword(s):  
Electrical Resistivity ◽  
Martensitic Transformation ◽  
Thermal Cycling ◽  
Volume Fraction ◽  
Resistivity Measurement ◽  
Electrical Resistivity Measurement ◽  
X Ray Diffraction ◽  
Transformation Behavior ◽  
Thermally Induced ◽  
X Ray

The effect of thermal cycling on the transformation behavior of a Ti–24Nb–1Mo alloy was investigated by means of electrical resistivity measurement, transmission electron microscopy (TEM), X-ray diffraction (XRD), tensile test and Vickers hardness tests. Electrical resistivity changes were not observed in all alloys. It indicates that thermally induced martensitic transformation does not take place in the alloys. After thermal cycling between 298 K and 77 K, clear X-ray diffraction peaks corresponding to ωath phase, which did not exist before thermal cycling, were observed. Volume fraction of ωath phase increased as increasing the number of thermal cycling. ωath phase formed during thermal cycling increased hardness of the alloy. Although thermally induced martensitic transformation did not occur in the alloys, superelastic deformation behavior was observed in the alloys. The superelastic recovery ratio decreased from 81% to 41% by increasing the number of thermal cycling, which came from the increase in the volume fraction of ωath phase.

Effect of Precipitate on Thermal Aging Effect of 17-4PH Martensitic Stainless Steel Used as Valve Stem in Nuclear Power Plant

2019 ◽  
Vol 944 ◽  
pp. 466-472
Author(s):  
Bing Bai ◽  
Chang Yi Zhang ◽  
Pei Pei Zhang ◽  
Wen Yang
Keyword(s):  
Stainless Steel ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Thermal Aging ◽  
Nuclear Power ◽  
Power Plants ◽  
Martensitic Stainless Steel ◽  
Volume Fraction ◽  
Aging Effect ◽  
Valve Stem

The valve stem used in the main steam system of nuclear power plant is usually 17-4PH martensitic stainless steel. When it served in 300°C for a long time, the thermal aging embrittlement of valve stem will be significant, with the performance of the ductile brittle transition temperature (DBTT) and the hardness increased, the upper stage energy (USE) decreased. It will increase the risk of brittle fracture of the valve stem, and seriously affect the safety and economic operation of nuclear power plant (NPP). Similar cases have occurred in foreign nuclear power plants. Therefore, it is important to study the thermal aging effect of the 17-4PH steel used as valves in nuclear power plant. In this work, the 17-4PH martensitic stainless steel samples served in nuclear power plant for many years were studied, and they exhibit obvious thermal aging embrittlement. By use of small angle neutron scattering (SANS) and three-dimensional atomic probe (3DAP), the nanosize precipitate in stainless steel is studied. The results show that the size of the larger cluster (~7nm) in stainless steel increases and the volume fraction of the cluster with size of ~1nm increases obviously after thermal aging. The larger nanosize precipitate was growing up during long service at high temperature, and precipitation of the smaller ones continuously occurred. Combing with the results of 3DAP, the nanosize clusters were formed by segregation of Ni, Mn and other elements with Cu-rich cluster, which are mainly in the form of Cu core and Ni-Mn shell.

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