scholarly journals Effect of Martensitic Transformation and Grain Misorientation on Surface Roughening Behavior of Stainless Steel Thin Foils

Eng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 372-385
Author(s):  
Abdul Aziz ◽  
Ming Yang ◽  
Tetsuhide Shimizu ◽  
Tsuyoshi Furushima
Keyword(s):  
Stainless Steel ◽  
Volume Fraction ◽  
Thin Foil ◽  
Total Strain ◽  
Coarse Grain ◽  
Uniaxial Tensile ◽  
Surface Roughening ◽  
Fine Grain ◽  
Thin Foils ◽  
Grain Misorientation

The surface roughening (Ra), martensitic phase transformation (MPT), and grain misorientation (GMO) behavior of stainless steel 304 and 316 in various grain sizes (Dg) were studied experimentally, including five cycles of sequential uniaxial tensile stress testing and Scanning Electron Microscope-Electron Back Scattered Diffraction (SEM-EBSD) investigation. The MPT and GMO characteristics were sequentially investigated using tensile testing and SEM-EBSD analysis. The correlation between MPT, GMO, martensitic volume fraction (Mf), and Ra behavior were investigated. The experimental results showed that increasing the total strain from 5.0% to 25.0% increased the MPT, GMO, and Mf, which were transformed from the metastable austenitic phase in stainless steel (SUS) 304. The increasing total strain increased Ra for all kinds of Dg. Furthermore, SUS 304 and SUS 316 were used to compare the roughening mechanism. The MPT was very high and spread uniformly in fine grain of SUS 304 thin foil, but the MPT was low and not uniform in coarse grain of SUS 304 thin foil. There was no MPT in SUS 316 thin foil, both in coarse and fine grain. The GMO in fine grains, both in SUS 304 and SUS 316 thin foils, spread uniformly. The GMO in coarse grains, both in SUS 304 and SUS 316 thin foils, did not spread uniformly. Surface roughness increased higher in coarse grain than fine grain for both of SUS 304 and SUS 316 thin foil. SUS 304 increased higher than SUS 316 thin foil. The effect of inhomogeneous deformation due to the MPT is a more important factor than GMO in coarse grain.

scholarly journals Effect of Martensitic Transformation and Grain Size on the Surface Roughening Behavior in SUS 304 and SUS 316 Thin Metal Foils

Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 167-182
Author(s):  
Abdul Aziz ◽  
Ming Yang
Keyword(s):  
Volume Fraction ◽  
Stress Test ◽  
Strain Level ◽  
Coarse Grain ◽  
Uniaxial Tensile ◽  
Surface Roughening ◽  
Initial State ◽  
Austenitic Phase ◽  
Fine Grain ◽  
Grain Misorientation

The surface roughening and martensitic phase transformation (MPT) of SUS 304 and SUS 316 were studied through two experiments: a uniaxial tensile stress test, repeated for five cycles, and an Scanning Electron Microscope–Electron Backscaterr Diffraction (SEM-EBSD) investigation. The MPT and martensitic volume fraction (Mf) were evaluated following the tensile test. The correlation between MPT, Mf, and surface roughening behavior was investigated. The experiment showed that an increase in the strain level from 0.4% to 1% increased the MPT and Mf, which transformed from a metastable austenitic phase in SUS 304. The increased strain level increased the surface roughening for various grain sizes (Dg), from fine grain (Dg < 3 μm) to coarse grain (Dg ≥ 3 μm). SUS 304 and SUS 316 are used so that the surface roughening mechanism between SUS 304 and SUS 316, with different phase conditions and at a similar Dg, can be determined. The results showed that the surface roughening increased for both fine and coarse grain at strain levels of 0.4% and 1%; however, a larger increase of surface roughening was obtained for coarse grain. In coarse grain, surface roughening increased significantly not only with a low MPT, but also with a low grain deformation. In coarse grain, the surface roughening increased proportionally to the strain level (εp) because of the low MPT and weak grain. In fine grain, the surface roughening did not increase proportionally to the εp because of the high MPT, which increased the grain strength in SUS 304. In the fine grain of SUS 304, the increase of surface roughening was nearly the same both at strain levels of 0.4% and 1%, because the MPT and Mf were nearly the same. The surface roughening with the same εp and almost the same Dg in SUS 304 and SUS 316 fine grain was nearly the same, because the grain deformation almost produced the same relative inclination between neighboring grains in the initial state direction to the surface. The inter-grain movement changed the grain orientation. Based on kernel average misorientation (KAM) mapping, the local grain misorientation in SUS 304 was higher than that in SUS 316. This indicated that the fine-grain SUS 304 is harder than the fine-grain SUS 316. There is no MPT in SUS 316 because of the higher austenitic phase, which is affected by the austenitic former, such as Ni.

Effect of Temperature and Grain Size on the Corrosion Behavior of 316L Stainless Steel in Seawater

2011 ◽  
Vol 299-300 ◽  
pp. 175-178 ◽  
Author(s):  
Sen Sen Xin ◽  
Jian Xu ◽  
Feng Jun Lang ◽  
Mou Cheng Li
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Corrosion Behavior ◽  
316L Stainless Steel ◽  
Seawater Temperature ◽  
Effect Of Temperature ◽  
Coarse Grain ◽  
Pitting Potential ◽  
Fine Grain ◽  
Different Grain Size

The corrosion behavior of 316L stainless steel was investigated in seawater at different temperature by using cyclic anodic polarization. The results indicated that two 316L specimens with different grain size showed similar pitting potential at 25°C. The increase of seawater temperature led to the linear decrease of pitting potential and repassivation potential. Because the pitting resistance of fine grain steel reduced larger than that of coarse grain steel with increasing temperature, the latter had a higher pitting potential about 60 mV at 85°C. Compared with the coarse grain steel, the fine grain steel showed a longer induction time for pitting at 65°C.

Effects of Microstructure on Mechanical Properties of HRS Processed SUS316L Stainless Steel

2007 ◽  
Vol 26-28 ◽  
pp. 421-424 ◽  
Author(s):  
Hiroshi Fujiwara ◽  
Masashi Nakatani ◽  
Yasuro Iwahashi ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Volume Fraction ◽  
Steel Powder ◽  
Core Structure ◽  
Grain Structure ◽  
Fine Grain ◽  
Coarse Grains ◽  
Nano Grains ◽  
Microstructure Of Material

Mechanical milled SUS316L stainless steel powder is applied to hot roll sintering (HRS) process. Microstructure and mechanical properties of the HRS material is investigated. Microstructure of material produced by HRS process consists of the shell and core hybrid microstructure, that is, a shell structure with nano grains and a core structure with work-hardened coarse grains. The fine grain structure corresponding to the shell area has (austenite + sigma) nano duplex structure. Work-hardened structure in the core area composes of an austenite phase. The HRS material demonstrates not only superior strength but also enough elongation. Mechanical properties are strongly influenced by the shell/core structure, such as grain size, shell/core size and/or the volume fraction. The shell and core nano-duplex hybrid microstructure by the HRS process has been proved to be very effective to improve mechanical properties.

Very thin foil thickness measurement by energy loss microspectroscopy

1986 ◽  
Vol 44 ◽  
pp. 718-719
Author(s):  
R.W. Carpenter ◽  
Peter R.T. Jang
Keyword(s):  
Thin Film ◽  
Stainless Steel ◽  
Energy Loss ◽  
Thin Foil ◽  
Single Scattering ◽  
Thickness Measurement ◽  
Foil Thickness ◽  
Crystalline Materials ◽  
Thin Foils

A simple experimental method for quantitative determination of foil thickness in very thin regions used for HREM and microanalysis under the single scattering or thin film approximations would be very useful and timely. Most current methods rely on diffraction and are applicable only to crystalline materials, with a lower thickness limit of about ξg, or are difficult to apply to very thin foils. Energy loss microspectrscopy avoids most of these difficulties. This note reports first applications of the method to wedge foils of silicon and austenitic stainless steel.

Effect of Co on microstructure and mechanical properties of precipitation hardening stainless steel

2020 ◽  
Vol 117 (1) ◽  
pp. 116
Author(s):  
Xiang LV ◽  
De-ning Zou ◽  
Jiao Li ◽  
Yang Pang ◽  
Yu-nong Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Stainless Steel ◽  
Precipitation Hardening ◽  
Volume Fraction ◽  
X Ray ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Transmission Electron ◽  
Solution Strengthening

The effects of Co element on the microstructure of precipitation hardening stainless steel was investigated by metallographic microscope (OM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD), and the mechanical properties were measured by tensile, hardness and impact tests. The results show that with increasing Co content, the volume fraction of reversion austenite is increased. The precipitation of ε-Cu phase is remarkably decreased, leading to the improvement of ductility, while the strength and hardness are decreased. Co element improves the strength and toughness of stainless steel through fine-grain strengthening, solution strengthening and austenitic toughening.

Effects of Superplasticity in Boronizing of Duplex Stainless Steel

2006 ◽  
Vol 326-328 ◽  
pp. 1233-1236 ◽  
Author(s):  
Rafidah Hasan ◽  
Iswadi Jauhari ◽  
Hiroyuki Ogiyama ◽  
Raden Dadan Ramdan
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Surface Hardness ◽  
Load Condition ◽  
Boride Layer ◽  
Coarse Grain ◽  
Superplastic Behavior ◽  
Compression Load ◽  
Fine Grain ◽  
Hardness Values

In this research, conventional boronizing process (CB) and a new method of boronizing process under compression load condition (LB) were conducted and compared in order to study the effect of superplasticity on boronized substrate. Both processes were conducted on duplex stainless steel (DSS) with two different microstructures; as-received DSS with coarse grain microstructure (CDSS); and thermo-mechanically treated DSS with fine grain microstructure (FDSS) which can show superplastic behavior at high temperatures. Both processes were conducted at duration of 6 hours and temperatures between 1123 and 1223 K. All of boronized specimens demonstrated thin, smooth and compact morphology of boride layer. For CDSS, both CB and LB processes produced about similar surface hardness values within the range of 1425 – 2330 HV. For FDSS, CB process produced surface hardness between 1522 and 2601 HV, while under LB, the highest surface hardness values in the range of 1659 - 2914 HV were obtained. The result shows that introduction of load during boronizing has initiated superplastic deformation on FDSS thus accelerated diffusion of boron atoms into surface which finally lead to significantly higher surface hardness.

Influence of X-Ray Induced Fluorescence on Energy Dispersive X-Ray Analysis of Thin Foils

1977 ◽  
Vol 35 ◽  
pp. 328-329
Author(s):  
E. A. Kenik ◽  
J. Bentley
Keyword(s):  
Thin Foil ◽  
Electron Excitation ◽  
Simple Approach ◽  
Foil Thickness ◽  
X Rays ◽  
X Ray ◽  
Hole Spectrum ◽  
Illumination System ◽  
Thin Foils ◽  
Intensity Ratios

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

Effets of surfaces on precipitate morphology in irradiated thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 654-655
Author(s):  
D.I. Potter ◽  
A. Taylor
Keyword(s):  
Ion Irradiation ◽  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
Al Alloy ◽  
Bright Field Image ◽  
Dislocation Loops ◽  
Precipitate Morphology ◽  
Thin Foils

Thermal aging of Ni-12.8 at. % A1 and Ni-12.7 at. % Si produces spatially homogeneous dispersions of cuboidal γ'-Ni3Al or Ni3Si precipitate particles arrayed in the Ni solid solution. We have used 3.5-MeV 58Ni+ ion irradiation to examine the effect of irradiation during precipitation on precipitate morphology and distribution. The nearness of free surfaces produced unusual morphologies in foils thinned prior to irradiation. These thin-foil effects will be important during in-situ investigations of precipitation in the HVEM. The thin foil results can be interpreted in terms of observations from bulk irradiations which are described first.Figure 1a is a dark field image of the γ' precipitate 5000 Å beneath the surface(∿1200 Å short of peak damage) of the Ni-Al alloy irradiated in bulk form. The inhomogeneous spatial distribution of γ' results from the presence of voids and dislocation loops which can be seen in the bright field image of the same area, Fig. 1b.

Growth of hematite by surface oxidation of olivine

1988 ◽  
Vol 46 ◽  
pp. 800-801
Author(s):  
S. McKernan ◽  
C. B. Carter
Keyword(s):  
Electron Microscope ◽  
Surface Oxidation ◽  
Thin Foil ◽  
Nucleation And Growth ◽  
Ion Milling ◽  
Annealed Material ◽  
Thin Foils ◽  
Natural Olivine ◽  
Approximate Composition ◽  
Second Phases

The oxidation of natural olivine has previously been performed on bulk samples and the reactions followed by preparation of TEM specimens from the annealed material. These results show that below ∼1000°C hematite and amorphous silica are formed, particularly around dislocations. At higher temperatures magnetite and some enstatite-like phase are formed. In both cases the olivine is left almost totally Fe depleted. By performing the oxidation on characterized thin TEM specimens it is possible to obtain more information on the nucleation and growth of the second phases formed. The conditions in a thin foil, however, are very different from those in the bulk especially with regard to surface effects. The nucleation of precipitates in particular may be expected to occur differently in these thin foils than in the bulk.TEM specimens of natural olivine (approximate composition Mg+Fe+Si2o4) which had been annealed at 1000°C for 1 hr were prepared by mechanical polishing and dimpling, followed by Ar ion milling to perforation. The specimens were characterized in the electron microscope and then heated in air in alumina boats to 900°C for between 30 and 180 minutes.

Sign in / Sign up

Export Citation Format

Share Document