The Effect of Heating Rate on Texture and Formability of Ti-Nb Stabilized Ferritic Stainless Steel

2018 ◽  
Vol 786 ◽  
pp. 3-9
Author(s):  
Matias Jaskari ◽  
Antti Järvenpää ◽  
Pentti L. Karjalainen
Keyword(s):  
Stainless Steel ◽  
Heating Rate ◽  
Ferritic Stainless Steel ◽  
Heating Temperature ◽  
Diffraction Method ◽  
Processing Route ◽  
High Heating Rate ◽  
Rolled Sheet ◽  
Heating Rates ◽  
Cold Rolled

Typical applications of ferritic stainless steels require good formability of the material that is highly dependent on the processing route. In this study, the effects of the heating rate and peak heating temperature on the texture and deep drawability (R-value) of a 78% cold rolled, stabilized 18Cr (AISI 441) ferritic stainless steel were studied. Pieces of cold rolled sheet were heated in a Gleeble 3800 simulator at the heating rates of 25 °C/s and 500 °C/s to various temperatures up to 1150 °C for 10 s holding before cooling at a rate of 35 °C/s. Microstructures were characterized and the texture of the annealed samples determined by the electron backscatter diffraction method. It was established that the high heating rate of 500 °C/s promotes the nucleation of grains with the near {111}<uvw> orientations during the early state of the recrystallization. The maximum texture intensities were found at {554}<225>. The more effective nucleation of these grains resulted in a finer grain size and an increased intensity of the gamma-fibre texture which led to enhanced R-values. At high peak temperatures, the intense grain growth took place.

The Effect of Heating Rate and Temperature on Microstructure and R-Value of Type 430 Ferritic Stainless Steel

2018 ◽  
Vol 941 ◽  
pp. 364-369
Author(s):  
Matias Jaskari ◽  
Antti Järvenpää ◽  
L. Pentti Karjalainen
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Heating Rate ◽  
Ferritic Stainless Steel ◽  
Stainless Steels ◽  
High Heating Rate ◽  
Rolled Sheet ◽  
Ferritic Stainless Steels ◽  
Cold Rolled ◽  
R Value

Typical applications of ferritic stainless steels require good formability of a steel that is highly dependent on the processing route. In this study, the effects of heating rate and peak temperature on the texture and formability of a 78% cold-rolled unstabilized 17%Cr (AISI 430) ferritic stainless steel were studied. The cold-rolled sheet pieces were heated in a Gleeble 3800 simulator at the heating rates of 25 °C/s and 500 °C/s up to various peak temperatures below 950 °C for 10 s holding before the final cooling at 35 °C/s to room temperature. Microstructures were characterized and the texture of the annealed samples determined by the electron backscatter diffraction method. The R-value in various directions was determined by tensile straining to 15%. It was established that the high heating rate of 500 °C/s tends to promote the nucleation of grains with the {111}<uvw> orientations during the early state of the recrystallization. The higher heating rate led to a slightly finer grain size and to a marginal improvement in the intensity of the gamma-fibre texture. A coarser grain size would be beneficial for the formability, but the grain growth was suppressed due to low peak temperatures and a short soaking time. Anyhow, the fast annealing resulted in an enhanced R-value in the transverse to rolling direction. The results indicate that even a short annealing cycle is plausible for producing ferritic stainless steels with the formability properties comparable to those of commercial counterparts.

Influence of Annealing Heating Rate on Nb Ferritic Stainless Steel Microstructure and Texture

2013 ◽  
Vol 753 ◽  
pp. 217-220 ◽  
Author(s):  
Daniella Gomes Rodrigues ◽  
Tarcísio Reis Oliveira ◽  
Dogoberto Brandão Santos ◽  
Berenice Mendonça Gonzalez
Keyword(s):  
Stainless Steel ◽  
Heating Rate ◽  
Ferritic Stainless Steel ◽  
Volume Fraction ◽  
Recrystallization Temperature ◽  
Homogeneous Distribution ◽  
High Heating Rate ◽  
Heating Rates ◽  
Steel Microstructure ◽  
Annealing Cycle

The cold rolled band of the niobium stabilized type ASTM 430 ferritic stainless steel with 85 % thickness reduction was annealed with heating rates of 0.10, 6.8, 23.5 and 41.5 °C/s and a soaking time of 24 s. The changes in microstructure and texture were followed by interruptions in the annealing cycle at temperatures of 780, 830 and 880 °C. Annealing at the lower heating rate was more effective for the development of γ-fiber than the annealing performed with high heating rate. The increased rate of heating provided an increase in the onset recrystallization temperature, a reduction in average grain diameter and a more homogeneous distribution throughout the thickness. The specimens with higher volume fraction of the γ-fiber annealed with low heating rate showed a high average coefficient of anisotropy R =1.99.

Studies on Martensite Transformation in a Metastable Austenitic Cr-Mn Stainless Steel

2013 ◽  
Vol 762 ◽  
pp. 424-430 ◽  
Author(s):  
Anna P. Kisko ◽  
Ludovica Rovatti ◽  
R.D.K. Misra ◽  
Puspendu Sahu ◽  
Juho Talonen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Heating Rate ◽  
Magnetic Measurements ◽  
Isothermal Holding ◽  
Ferromagnetic Phase ◽  
Annealing Duration ◽  
Heating Rates ◽  
Dimensional Changes ◽  
Transmission Electron ◽  
Cold Rolled

The influences of the heating rate and annealing duration on martensite formation and its reversion to austenite have been investigated in a 60% cold-rolled metastable high-manganese austenitic Type 204Cu stainless steel. A Gleeble 3800 thermomechanical simulator was used for dilatometric measurements. Cold-rolled steel pieces were either heated up to 1000 °C at various heating rates between 5 °C/s and 150 °C/s followed by quenching to room temperature, or heated and held at temperatures in the range of 450 620 °C for different durations between 0.1 600 s. In heating experiments, dilatation curves revealed an expansion of a specimen starting around 550 °C followed by contraction, both processes depending on the heating rate. These dimensional changes could be correlated to the formation and reversion of a ferromagnetic phase, α-martensite. Some martensite was also formed during isothermal holding in connection with tempering of the pre-existing α-martensite before the following reversion, as established by magnetic measurements. Tempering of martensite was revealed by microhardness behaviour, X-ray diffraction analysis and transmission electron microscopy.

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Estimation of Residual Stress in Cold Rolled Iron-Disks Using Magnetic and Ultrasonic Methods and Neutron Diffraction Technique

1994 ◽  
Vol 376 ◽  
Author(s):  
V.L. Aksenov ◽  
A.M. Balagurov ◽  
G.D Bokuchava ◽  
J. Schreiber ◽  
Yu.V. Taran Frank
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Sheet Metal ◽  
Diffraction Method ◽  
Calibration Procedure ◽  
Rolled Sheet ◽  
Forming Process ◽  
Practical Applications ◽  
Ultrasonic Methods ◽  
Cold Rolled

ABSTRACTVariation of internal stress states in cold rolled sheet metal can essentially influence the result of forming processes. Therefore it is important to control the forming process by a practicable in line testing method. For this purpose magnetic and ultrasonic nondestructive methods are available. However, it is necessary to calibrate these techniques. This paper describes a first step of such a calibration procedure making use of the neutron diffraction method. On the basis of the diffraction results an assessment of the magnetic and ultrasonic methods for the estimation of residual stress in the cold rolled iron-disks was made. Reasonable measuring concepts for practical applications to forming processes with cold rolled sheet metal are discussed.

scholarly journals XPS and Electron Microscopy Study of Oxide-Scale Evolution on Ignition Resistant Mg-3Ca Alloy at Low and High Heating Rates

2020 ◽  
Vol 1 ◽  
Author(s):  
L. A. Villegas-Armenta ◽  
R. A. L. Drew ◽  
M. O. Pekguleryuz
Keyword(s):  
Oxide Scale ◽  
Heating Rate ◽  
Photoelectron Spectroscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
High Heating Rate ◽  
Heating Rates ◽  
Oxide Interface ◽  
Protective Oxide ◽  
High Heating

AbstractEarlier work by the authors suggested that the formation of molten eutectic regions in Mg-Ca binary alloys caused a discrepancy in ignition temperature when different heating rates are used. This effect was observed for alloys where Ca content is greater than 1 wt%. In this work, the effect of two heating rates (25 °C/min and 45 °C/min) on the ignition resistance of Mg-3Ca is evaluated in terms of oxide growth using X-ray Photoelectron Spectroscopy. It is found that the molten eutectic regions develop a thin oxide scale of ~100 nm rich in Ca at either heating rate. The results prove that under the high heating rate, solid intermetallics are oxidized forming CaO nodules at the metal/oxide interface that eventually contribute to the formation of a thick and non-protective oxide scale in the liquid state.

scholarly journals Effects of Heating Rate on Formation of Globular and Acicular Austenite during Reversion from Martensite

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 266 ◽  
Author(s):  
Xianguang Zhang ◽  
Goro Miyamoto ◽  
Yuki Toji ◽  
Tadashi Furuhara
Keyword(s):  
Heating Rate ◽  
High Temperatures ◽  
The Other ◽  
Growth Mode ◽  
High Heating Rate ◽  
Heating Rates ◽  
Other Hand ◽  
High Heating ◽  
Martensite Matrix

The effects of heating rate on the formation of acicular and globular austenite during reversion from martensite in Fe–2Mn–1.5Si–0.3C alloy have been investigated. It was found that a low heating rate enhanced the formation of acicular austenite, while a high heating rate favored the formation of globular austenite. The growth of acicular γ was accompanied by the partitioning of Mn and Si, while the growth of globular γ was partitionless. DICTRA simulation revealed that there was a transition in growth mode from partitioning to partitionless for the globular austenite with an increase in temperature at high heating rate. High heating rates promoted a reversion that occurred at high temperatures, which made the partitionless growth of globular austenite occur more easily. On the other hand, the severer Mn enrichment into austenite at low heating rate caused Mn depletion in the martensite matrix, which decelerated the reversion kinetics in the later stage and suppressed the formation of globular austenite.

Modification of Banding in Dual-Phase Steels via Thermal Processing

2014 ◽  
Vol 783-786 ◽  
pp. 1067-1072 ◽  
Author(s):  
K. Mukherjee ◽  
L.S. Thomas ◽  
C. Bos ◽  
David K. Matlock ◽  
John G. Speer
Keyword(s):  
Heating Rate ◽  
Thermal Processing ◽  
Thermomechanical Processing ◽  
Rolled Sheet ◽  
Dual Phase ◽  
Heating And Cooling ◽  
Heat Treated ◽  
Cold Rolled ◽  
Dp780 Steel ◽  
Microscopic Techniques

The potential to utilize controlled thermal processing to minimize banding in a DP780 steel with 2 wt pct Mn was evaluated on samples processed on a Gleeble® 3500 thermomechanical processing simulator. All processing histories were selected to result in final dual-phase steel microstructures simulating microstructures achievable during annealing of initially cold rolled sheet. Strip samples were processed to evaluate the effects of heating rate, annealing time, annealing temperature, and cooling rate. The degree of banding in the final microstructures was evaluated with standard light optical microscopic techniques. Results are presented to illustrate that the extent of banding depended on control of both heating and cooling rates, and a specific processing history based on a two-stage heating rate can be used to minimize visible banding in selected final heat treated products.

Effect of the Rolling Draughts on the Evolution of Textures and Microstructures in 17.5 Cr-1.1 Mo Ferritic Stainless Steel Sheet

2005 ◽  
Vol 495-497 ◽  
pp. 363-368
Author(s):  
Soo Ho Park ◽  
Hyung Gu Kang ◽  
Yong Deuk Lee ◽  
Jae Chul Lee ◽  
Moo Young Huh
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Steel Sheet ◽  
Recrystallization Annealing ◽  
Reduction Degree ◽  
Stainless Steel Sheet ◽  
Steel Sheets ◽  
Hot Band ◽  
Cold Rolled ◽  
Number Of Passes

In order to investigate the effect of the reduction degree per rolling pass on the evolution of recrystallization textures and microstructures, the hot band of 17.5 Cr-1.1 Mo ferritic stainless steel sheets were cold rolled with lubrication according to two processing routes, by which different reduction degrees per pass were introduced. Rolling with a large number of passes led to the formation of fairly homogeneous rolling textures at all through-thickness positions. In contrast, cold rolling with large draughts resulted in pronounced texture gradients along the thickness direction. After recrystallization annealing, the texture maximum was obtained at {334}<483> in all samples regardless of the rolling routes and thickness layers. During subsequent annealing, recrystallization was observed to be faster in those grains with {111}<uvw> orientations, while it was retarded in grains having orientations close to {001}<110>.

Sign in / Sign up

Export Citation Format

Share Document