Grain Boundary Engineering of Metals by Thermo-Mechanical Treatment

2010 ◽  
Vol 659 ◽  
pp. 349-354
Author(s):  
Péter János Szabó
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stainless Steels ◽  
Mechanical Treatment ◽  
Austenitic Stainless Steels ◽  
Grain Boundary Engineering ◽  
Aisi 304 ◽  
Relative Fraction ◽  
Heat Treated ◽  
Thermo Mechanical Treatment

The relative fraction of the special grain boundaries can be increased by thermo-mechanical treatments. During this work, AISI 304-type austenitic stainless steels were plastically deformed and heat treated under different conditions, and then the grain boundary network, which developed during the treatments was investigated. Results showed that cyclic application of large cold rolling (30% reduction of thickness) and quick heat treatment at high temperature (800 °C, 2 minutes) gave the best grain boundary network. A possible reason of this behaviour is that grains which did not recrystallize after the first cycle, stored a high elastic energy, which helped the grain boundary motions in the next cycles. To characterize the developed grain boundary network, different parameters are also suggested in this paper.

Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

1991 ◽  
Vol 49 ◽  
pp. 604-605
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Deformation Twin ◽  
Austenitic Stainless Steels ◽  
Carbide Precipitation ◽  
Strain Induced Martensite ◽  
Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

Grain Growth Control in Grain Boundary Engineered Microstructures

2012 ◽  
Vol 715-716 ◽  
pp. 103-108 ◽  
Author(s):  
Valerie Randle ◽  
Mark Coleman
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Stainless Steels ◽  
Growth Control ◽  
Austenitic Stainless Steels ◽  
Grain Boundary Engineering ◽  
Size Measurement ◽  
Annealing Twins ◽  
And Control ◽  
Measurement And Control

Grain boundary engineering (GBE) to promote degradation-resistant interfaces in the microstructure usually requires that the grain size remains small so that strength is not compromised. Aspects of grain size measurement and control will be reviewed and discussed for a variety of GBE materials such as copper, nickel, nickel-based alloys and austenitic stainless steels, particularly in the light of the high proportion of annealing twins that constitute the GBE microstructure.

scholarly journals Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering

2021 ◽  
pp. 110246
Author(s):  
Hossein Eskandari Sabzi ◽  
Everth Hernandez-Nava ◽  
Xiao-Hui Li ◽  
Hanwei Fu ◽  
David San-Martín ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Powder Bed Fusion ◽  
Grain Boundary Engineering ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

Effect of Thermo-Mechanical Heat Treatment on Microstructure and Mechanical Property of 2197 Al-Li Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1621-1625 ◽  
Author(s):  
Bai Ping Mao ◽  
Jun Peng Li ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Treatment ◽  
Tensile Tests ◽  
Strengthening Effect ◽  
Precipitated Phase ◽  
Heat Treated ◽  
Peak Aged ◽  
Aged State ◽  
Thermo Mechanical Treatment

Effects of thermo-mechanical treatment on the mechanical properties and microstructure of 2197 alloy were studied through analyses of the mechanical properties by tensile tests and TEM observation of thermo-mechanical heat treated 2197 alloy plates of various states. Results show that the dominating precipitated phase of peak-aged 2197 alloy during thermo-mechanical heat treatment is T1 phase of which the size is 50~150nm. The precipitation and growth of T1 phase are accelerated due to the existed nucleation sites for heterogeneous nucleation of T1 phase offered by thermo-mechanical treatment, therefore, the time for 2197 alloy to reach the peak-aged state is shorten. The strength of 2197 alloy for peak-aged state is increased through thermo-mechanical treatment because the strengthening effect of T1 phase with higher aspect ratio is bigger than that of δ′ and θ′ phases.

Prevention of Weld Decay of Austenitic Stainless Steels by Grain Boundary Engineering

2016 ◽  
Vol 85 (6) ◽  
pp. 588-592
Author(s):  
Shun TOKITA ◽  
Hiroyuki KOKAWA ◽  
Yutaka SATO S. ◽  
Hiromichi FUJII T.
Keyword(s):  
Grain Boundary ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Grain Boundary Engineering

Effect of Thermo-Mechanical Treatment (TMT) on Hardness of Heat-Treated Al-Mg-Si (6082) Alloys: Experimental Correlation Using (DOE) Method

2013 ◽  
Vol 376 ◽  
pp. 163-172 ◽  
Author(s):  
Mahmoud M. Tash ◽  
S. Alkahtani
Keyword(s):  
Heat Treatment ◽  
Aging Time ◽  
Solution Heat Treatment ◽  
Mechanical Treatment ◽  
Cold Work ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Solution Treated ◽  
Heat Treated ◽  
Thermo Mechanical Treatment

The present study was undertaken to investigate the effect of Thermo-mechanical Treatment (TMT) on aging and hardness of Al-Mg-Si (6082) alloys. The effect of cold work after solution treatment, aging time and temperature on the microstructure and hardness were studied. Hardness measurements were carried out on specimens prepared from 6082 alloys in the as solution treated specimens and heat-treated conditions, using different cold work percentage before aging treatment. Aging treatments were carried out for the as solution treated specimens (after quenching in water) as well as for the as cold worked specimens (after solution treatment and quenching in water). The specimens were aged at different conditions; Natural aging was carried out at room temperature for different periods of time. Artificial aging was performed at 100 °C, 150 °C, and 200 °C for various times. It is noticed that cold work, following solution treatment, accelerates the precipitation rate leading to a rise in strength.A statistical design of experiments (DOE) approach using fractional factorial design was applied to determine the influence of controlling variables of cold work and heat treatment parameters and any interactions between them on the hardness of 6082 alloys. A mathematical model is developed to relate the alloy hardness with the different metallurgical parameters i.e. Cold work prior solution heat treatment (CWBSHT), Cold work after solution heat treatment (CWASHT), Pre-aging Temperature (PA T0C), Pre-aging time (PA t h), Aging temperature (AT0C), Aging time (At h), Cold work after aging treatment (CWAAT), Annealing temperature (An.T0C) and Annealing time (An.t min) to acquire an understanding of the effects of these variables and their interactions on the hardness of Al-Mg-Si 6082 alloys.

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