Microstructural Evolution and Deformation Behavior of Stainless Steel in Semi-Solid State

2006 ◽  
Vol 116-117 ◽  
pp. 681-685 ◽  
Author(s):  
Jing Yuan Li ◽  
Sumio Sugiyama ◽  
Jun Yanagimoto
Keyword(s):  
Stainless Steel ◽  
Solid State ◽  
Austenitic Stainless Steel ◽  
Microstructural Evolution ◽  
Stainless Steels ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Steel Type ◽  
Semi Solid ◽  
Type 304

Thixoforming or Semi-Solid Metal Forming offers many advantages in comparison with casting and conventional forging. The purpose of the present study is to provide the basic microstructure and deformation data for austenitic and ferritic stainless steel under mushy state. As well known, the stainless steels solidify in different modes according to the different chemical compositions. In this paper, microstructural evolution of austenitic stainless steel type 304 which solidifies in FA mode ( L → L +δ → L +δ +γ →δ +γ →γ ),austenitic stainless steel type 310S which solidifies in A mode ( L → L +γ →γ ), and ferritic stainless steel type 430 which solidifies in F mode ( L → L +δ →δ )are investigated during partial remelting by way of SIMA (Strain Induced Melted Activation). The results show that A and F mode of stainless steels melt directly at the grain boundary without phase transformation during reheating. A banded structure, originating from the primary dendritic segregation of the original ingots, is observed in type 310S steel during further heating. On the other hand, a perfect globular and insegregative two-phase semi-solid structure L +δ can be obtained while heated beyond the banded three-phase L +δ +γ semi-solid state in FA mode austenitic stainless steel type 304. This spheroidization can be attributed to the peritectic reaction occurred in the L +δ +γ semi-solid state. In addition, simple compression tests of these alloys in semi-solid state for varied combination of deformation rate and deformation temperature are conducted to examine the deformation behavior of stainless steel. Flow stress curves exhibit abrupt change in various alloys, even though in the same alloy such as type 304, various flow stresses are observed according to the difference in inner microstructure or morphology. Stress of type 310S steel shows the most reduction as the deformation temperature increasing at the same strain rate condition. The Liquid is centralized to periphery by the compression force in all deformed test pieces. Fracture, observed in all alloys except type 304 steel in globular L +δ semi-solid state, should be resulted from the lack of liquid in L +δ +γ state of type 304 steel and solidification crack in type 310S and type 430 steel. Deformation of solid particles occurs only in L +δ +γ state of type 304 steel. Last in this paper, various deformation mechanisms are proposed for various microstructures.

scholarly journals Inhibition Effect of N, N'-Dimethylaminoethanol on the Pitting Corrosion Austenitic Stainless Steel Type 304

2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Roland Tolulope LOTO ◽  
Cleophas Akintoye LOTO ◽  
Patricia Abimbola POPOOLA ◽  
Tatiana FEDOTOVA
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Pitting Corrosion ◽  
Inhibition Effect ◽  
Steel Type ◽  
Type 304

Radiation-induced segregation in austenitic stainless steel type 304: Effect of high fraction of twin boundaries

2011 ◽  
Vol 528 (25-26) ◽  
pp. 7541-7551 ◽  
Author(s):  
Parag Ahmedabadi ◽  
V. Kain ◽  
K. Arora ◽  
I. Samajdar ◽  
S.C. Sharma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Twin Boundaries ◽  
Steel Type ◽  
Radiation Induced ◽  
High Fraction ◽  
Type 304

scholarly journals Defect Reduction in Ferritic Stainless Steels through Modelling Plastic Deformation and Metallurgical Evolution

2021 ◽  
Vol 3 (1) ◽  
pp. 22
Author(s):  
Silvia Mancini ◽  
Luigi Langellotto ◽  
Andrea Di Schino
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Microstructural Evolution ◽  
Stainless Steels ◽  
Hot Rolling ◽  
Hot Deformation ◽  
Rolling Process ◽  
Process Conditions ◽  
Ferritic Stainless Steels ◽  
Damage Models

Steel products made of ferritic steel can show some defects, such as jagged edges, following the hot rolling process. Aiming to identify the origin of this type of defect in order to help their reduction, an in-depth study has been carried out considering the hot rolling conditions of flat bars made of EN 1.4512 steel. A wide number of references to austenitic stainless steel can be found in literature: almost all the semi-empirical models describing the microstructural evolution during hot deformation refer to austenitic stainless steel. In this work, a comprehensive model for recrystallization and grain growth of the ferritic stainless steel grade EN 1.4512 is proposed, enriching the literature and works regarding ferritic stainless steels. Thermomechanical and metallurgical models have been implemented. The microstructural evolution and the damage of the material were calculated through the coupling of metallurgical and damage models. In the thermomechanical simulations of the roughing passes, three granulometry levels (PFGS) and three heating furnace temperatures were considered. The ferritic grain evolution metallurgical model was obtained by introducing apposite equations. The results highlight that the defect could be produced by process conditions that spark abnormal heating and consequently uncontrolled growth of the grains. The work-hardened grains undergo elongation during hot deformation without recrystallizing. Those grains “squeeze” the surrounding recrystallized grains towards the edges. Thus, on the edges occurs a series of cracks that macroscopically manifest themselves as jagged edges.

scholarly journals PENGARUH ASAM NITRAT TERHADAP LAJU KOROSI BAJA TAHAN KARAT AUSTENITIK 304 UNTUK KEPERLUAN KONSTRUKSI

2006 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
M.O.S Aritonang ◽  
Iqbal Fahri
Keyword(s):  
Stainless Steel ◽  
Nitric Acid ◽  
Austenitic Stainless Steel ◽  
Steel Type ◽  
Stainless Steel 304 ◽  
Type 304

Tujuan penelitian ini adalah untuk mengetahui laju korosi austenitik tipe stainless steel 304 attack nitric acid 65% dengan austenitic stainless steel tipe 304 serang nitric acid 85% untuk kepentingan konstruksi. Penelitian ini dilakukan di Balai Penelitian Bahan Kimia Departemen Perindustrian DKI Jakarta. Metodologi yang digunakan dalam penelitian ini adalah eksperimen dengan dua jenis perlakuan. Yaitu; kelompok pertama adalah austenitic stainless steel tipe 304 serangan asam nitrat 65% dan kelompok kedua adalah stainless steel tipe austenitic 304 menyerang asam nitrat 85%. Jumlah semua instrumen yang diuji adalah 10 buah dari dua jenis perawatan. Untuk mengetahui pengaruh korosi terhadap sifat mekanik austenitic stainless steel tipe 304 khususnya kekuatan tarik, dilakukan pengujian kekuatan terhadap dua grup austenitic stanless steel type 304 attack nitric acid. Jadilah sisi, dilaksanakan juga pengujian kekuatan terhadap satu kelompok austenitic stainless steel tipe 304 sebagai kelompok kontrol. Berdasarkan penelitian, temuan menunjukkan bahwa austenitic stainless steel tipe 304 menyerang asam nitrat 65% memiliki laju korosi 3,751 mm / tahun pada rata-rata dan austenitic stainless steel tipe 304 serangan asam nitrat 85% memiliki laju korosi 6,404 mm / tahun pada rata-rata . Data dari penelitian diuji dengan uji rata - rata dua ekor (uji - t), uji satu ekor, ekor kiri dengan alfa = 0,01, dan dari analisis dapat diperoleh thitung = - 11,53, nilainya adalah lebih kecil dari tTable = -2,90 yang H0 di area penolakan. Kualitas austenitik dari baja tahan karat tipe 304 terhadap serangan korosi, diikuti juga oleh kekuatan tarik tarik austenitic stainless steel tipe 304. Sebelum korosi austenitic stainless steel memiliki kekuatan tarik 60.107 kgf / mm2. Setelah korosi dengan asam nitrat 65% kekuatan tarik austenitic stainless steel tipe 304 menjadi 57,329 kgf / mm2. Demikian lagi, setelah korosi dengan asam nitrat daya tarik 85% baja tahan austenitik tipe 304 menjadi 55.349 kgf / mm2.

Microstructural Evolution During a Solid State Tube Pinch Weld of Type 304l Stainless Steel

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Paul S. Korinko
Keyword(s):  
Stainless Steel ◽  
Solid State ◽  
Grain Growth ◽  
Microstructural Evolution ◽  
304L Stainless Steel ◽  
Cycle Number ◽  
Ac Current ◽  
Weld Time ◽  
Concentrated Deformation ◽  
Type 304

Abstract Microstructure development is examined for a specialized spot weld that is used as a solid-state closure process for austenitic stainless steel tubing, referred to as pinch welding. In order to elucidate the microstructural evolution of the weld, a series of test welds were made at nominal conditions using tubing and production like components. These pinch welds normally terminate after twelve cycles of a 60 Hz AC weld process. In this study, production tubes were welded from one to twelve cycles and the microstructure and weld variables after each individual weld cycle number were characterized using radiography and optical metallography. Two electrochemical etchants were used to highlight different microstructural features. The study revealed that: (1) this type pinch weld is largely complete after about six cycles of 60 Hz AC current, half the weld time utilized; (2) the resistance, deformation, and closure length approach “steady-state” conditions after six cycles; and (3) both oxalic and nitric acid electrolytic etchants are useful for highlighting specific microstructural attributes of type 304 L stainless steel. Finally, two distinct microstructural regions can be identified for these welds: the edge of the weld, which is driven by concentrated deformation, recrystallization, and grain growth, and the center region, which is more typical of forge welding and micro-asperity breakdown followed by diffusion and grain-growth.

Chloride Stress Corrosion Cracking of Austenitic Stainless Steel—Effect of Temperature and pH★

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 60-64 ◽  
Author(s):  
L. R. SCHARFSTEIN ◽  
W. F. BRINDLEY
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Chloride Ions ◽  
Corrosion Cracking ◽  
Effect Of Temperature ◽  
Type 304 ◽  
Chloride Stress Corrosion Cracking

Abstract Overstressed U-bends of Types 304 and 347 stainless steels were exposed to water containing chloride ions to determine the susceptibility of these steels to stress corrosion cracking between the temperatures of 165 F and 200 F. The pH was controlled at 6.5 to 7.5 and 10.6 to 11.2 for the tests. At the high pH, cracks appeared at the edges with little evidence of pitting. At the neutral pH, cracks were found at the edges and associated with pits. Sensitized Type 304 had longer and deeper cracks than annealed Types 304 and 347 in the same exposure time. Conclusion is made that chloride stress corrosion cracking of these steels in the temperature range of 165 F to 200 F is less severe than that experienced at 500 F and that specific conditions are required for corrosion cracking to occur at all. 3.2.2

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