Correlation of grain boundary connectivity with grain boundary character distribution in austenitic stainless steel

Tsurekawa, Sadahiro; Nakamichi, Shinya; Watanabe, Tadao

doi:10.1016/j.actamat.2006.03.048

Cited by 123 publications

(70 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[51] Recent research supports the fact that the increase in grain size involves a greater amount of CSL boundaries. [52] It has also been demonstrated in Figure 7 that the DOS also follows a similar trend to that of f CSL and f R3 with increasing grain size. Additionally, like the f CSL and f R3 , the DOS remains very low with an average value of 1.7 below the grain size of~16 lm.…”

Section: Grain Size Dos and Csl Boundariessupporting

confidence: 52%

Modification of Sensitization Resistance of AISI 304L Stainless Steel through Changes in Grain Size and Grain Boundary Character Distributions

Singh

Chowdhury

Chattoraj

2008

Metall Mater Trans A

View full text Add to dashboard Cite

RAGHUVIR SINGH, SANDIP GHOSH CHOWDHURY, and INDRANIL CHATTORAJSensitization behavior of thermomechanically processed AISI 304L stainless steel has been investigated. The mechanical processing was carried out at deformations of 30 to 90 pct (reduction in thickness), and annealed subsequently at temperatures ranging from 800°C to 950°C for 15 to 60 minutes. Stainless steel was then sensitized at 675°C both for short (2 hours) and long (53 hours) durations. Thus treated specimens were characterized for grain boundary character distribution, grain size, and degree of sensitization (DOS). The increase in annealing temperature and time following mechanical processing showed an increase in grain size (up to 37 lm) and in the DOS. The fraction of coincident site lattice (CSL) boundaries (R3 to R29) was also noticed to increase with the annealing temperature, which implied that an increasing fraction of low energy boundaries did not cause a decrease in the DOS. The grain size through its effect on grain boundary surface area and the effective grain boundary energy correlated well with the extent of sensitization. Grain growth reduces the grain boundary surface area and the effective grain boundary energy as well, which, in turn, enhanced the DOS. A critical grain size (~<16 lm), below which, and correspondingly a critical effective grain boundary energy (~>0.05), above which, sensitization reduced to insignificant levels was observed.

show abstract

Section: Grain Size Dos and Csl Boundariessupporting

confidence: 52%

Modification of Sensitization Resistance of AISI 304L Stainless Steel through Changes in Grain Size and Grain Boundary Character Distributions

Singh

Chowdhury

Chattoraj

2008

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…[28] In the case of austenitic stainless steel having low stacking fault energy, the CSL frequency was found to increase with increasing grain size. [29] Interestingly, no definite correlation between CSL frequency and grain size was observed in the previous work. [30] To clarify this point, the relationship between GBCD and grain size was investigated in this study.…”

Section: Discussionmentioning

confidence: 79%

Grain Boundary Microstructural Control through Thermomechanical Processing in a Titanium-Modified Austenitic Stainless Steel

Mandal

Sivaprasad

Raj

et al. 2008

Metall Mater Trans A

View full text Add to dashboard Cite

The present study discusses the grain boundary microstructural control in a 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel (commonly known as alloy D9) through a one-step thermomechanical treatment. The experimental methodology adopted in this investigation was based on the strain annealing approach in which a small amount of strain (5 to 15 pct) was imparted on the solution-annealed (SA) sample. The cold-deformed samples were subsequently annealed at various temperatures (1173 to 1273 K) for different time periods (0.5 to 2 hours). It was observed that annealing after 5 pct deformation induces anomalous grain growth with a moderate increase in number fraction of coincidence site lattice (CSL) boundaries. However, a prestrain of 10 to 15 pct followed by annealing at 1273 K for 0.5 to 2 hours was found to be a suitable thermomechanical processing schedule to increase the number fraction of CSL boundaries (particularly R3 and its variants) significantly. Further, the well-connected network of random grain boundaries present in the SA specimen was substantially disrupted in these processing conditions due to the incorporation of R3 and its variants. The preceding results were discussed with reference to strain-induced grain growth vis-a`-vis strain-induced boundary migration (SIBM) following deformation and annealing.

show abstract

“…This figure suggests that the 2-D percolation threshold is approximately 70 % of the CSL frequency and that obviously low percolation is achieved over the threshold in the 2-D GBCD during the present GBE with 304 stainless steel. Previous studies 15,45) have also reported a CSL frequency of around 70 % for the 2-D percolation threshold in austenitic stainless steels (70 % in 304L steel 45) and 72 % in 316 steel 15) ). Monte Carlo simulation studies have dealt with grain boundary percolation.…”

Section: Percolation Of Random Boundaries In Gbemmentioning

confidence: 99%

Improvement of Transpassive Intergranular Corrosion Resistance of 304 Austenitic Stainless Steel by Thermomechanical Processing for Twin-induced Grain Boundary Engineering

et al. 2010

View full text Add to dashboard Cite

Grain boundary engineering (GBE) primarily aims to prevent the initiation and propagation of intergranular degradation along grain boundaries by frequent introduction of coincidence site lattice (CSL) boundaries into the grain boundary networks in materials. It has been reported that GBE is effective to prevent passive intergranular corrosion such as sensitization of austenitic stainless steels, but the effect of GBE on transpassive corrosion has not been clarified. In the present study, a twin-induced GBE utilizing optimized thermomechanical processing with small pre-strain and subsequent annealing was applied to introduce very high frequencies of CSL boundaries into type 304 austenitic stainless steels containing different phosphorus concentrations. The resulting steels showed much higher resistance to transpassive intergranular corrosion during the Coriou test, in comparison with the as-received ones. The high CSL frequency resulted in a very low percolation probability of random boundary networks in the over-threshold region and remarkable suppression of intergranular deterioration during GBE.KEY WORDS: grain boundary engineering; coincidence site lattice; thermomechanical processing; austenitic stainless steel; intergranular corrosion.of CSL boundaries into 316 austenitic stainless steel and consequently decreased the susceptibility to intergranular corrosion significantly.Intergranular corrosion of stainless steels can be divided into passive and transpassive corrosion, depending on the electrode potential region of the environment. 19,20) The previous studies have demonstrated that GBE is effective for preventing intergranular corrosion at passive potentials by sensitization due to intergranular carbide precipitation in 304 and 316 austenitic stainless steels. 11,15,16) Meanwhile, intergranular corrosion possibly occurs for stainless steel due to the preferential dissolution of phosphate and/or phosphorus segregated at grain boundaries under corrosion environment at transpassive potentials.21-27) GBE may probably be also effective to suppress the transpassive intergranular corrosion of austenitic stainless steels. The present study aimed to examine the effect of GBE on the transpassive intergranular corrosion of type 304 austenitic stainless steels containing different concentrations of phosphorus. Experimental ProceduresThe chemical compositions (mass%) of two 304 austenitic stainless steels used in the present study are shown in Table 1. One of them was an ordinary commercial 304 stainless steel containing 0.027 % phosphorus, termed "high-P". The other one was specially prepared to contain a low phosphorus concentration of 0.001 %, termed "low-P". The as-received 304 steels were solution heat treated at 1 323 K for 0.5 h, and termed base materials (BMs). The BMs, 6ϫ10ϫ40 mm 3 in size, were thermomechanically processed by a one-step, pre-strain plus annealing process at the similar parameters to the previous study, 11) i.e., cold-rolling by 5 % reduction in thickness and subsequent annealing at 1 220 K f...

show abstract

Correlation of grain boundary connectivity with grain boundary character distribution in austenitic stainless steel

Cited by 123 publications

References 21 publications

Modification of Sensitization Resistance of AISI 304L Stainless Steel through Changes in Grain Size and Grain Boundary Character Distributions

Modification of Sensitization Resistance of AISI 304L Stainless Steel through Changes in Grain Size and Grain Boundary Character Distributions

Grain Boundary Microstructural Control through Thermomechanical Processing in a Titanium-Modified Austenitic Stainless Steel

Improvement of Transpassive Intergranular Corrosion Resistance of 304 Austenitic Stainless Steel by Thermomechanical Processing for Twin-induced Grain Boundary Engineering

Contact Info

Product

Resources

About