Relation between Cracking of Intermetallic Coating Layer of Galvannealed Steel Sheet and Grain Boundary of Substrate Steel

although the bonding strength in coat (i) s (i),int. was same (s (i),int. ϭ100 MPa). That is, the group-buckling occurs, originating from the buckling of the coating with weak interface, coat (ii) in the present analysis. Figures 8 and 9 shows the change of the debonding distance at (x, y)ϭ(L/2, W/2) and (0, W/2) with applied tensile strain for coat (i) and coat (ii). The position (x, y)ϭ (L/2, W/2) corresponded to the position getting the maximum value of the debonding distance. The position (x, y)ϭ (0, W/2) corresponded to the center of the coating which is important to evaluate the progression of interfacial debonding.As shown in Fig. 9, the lower the bonding strength of the coat (ii)-substrate interface s (ii),int. , the larger became the debonding distance of coat (ii) at both (x, y)ϭ(L/2, W/2) and (0, W/2).As shown in Fig. 8, the debonding distance at both (x, y)ϭ(L/2, W/2) and (0, W/2) in coat (i) also became larger with low bonding strength of the coat (ii)-substrate interface s (ii),int. . In addition, the applied strain at which the in- terfacial debonding started became lower with low bonding strength of coat (ii) s (ii),int. at (x, y)ϭ(0, W/2) in coat (i), as shown in Fig. 8(b). From this result, it is expected that the debonding of coat (ii) affected not only on the maximum debonding distance of coat (i) but also the progression of interfacial debonding of coat (i). From the comparison of the Fig. 8 and Fig. 9, it was found that the debonding distance of coat (ii) was not directly reflected in that of coat (i). As shown in Fig. 8, the debonding distance of the coat (i) under the condition of s (ii),int. ϭ100 MPa was only slightly smaller than that under the condition of s (ii),int. ϭ80 MPa, in contrast to the debonding distance of the coat (ii) which was much larger under the condition of s (ii),int. ϭ80 MPa.The progress of the debonded area of the coat (i)-substrate interface and coat (ii)-substrate interface with increasing applied strain, under the condition of s (i),int. ϭ 100 MPa and s (ii),int. ϭ(a) 100 MPa, (b) 80 MPa and (c) 60 MPa, are shown in Figs. 10 and 11, respectively. The debonded part of the coating is shown in black color in Figs. 10 and 11. As shown in Fig. 10(a), the debonded area progressively increases from the edge (x, y)ϭ(L/2, W/2), and rapidly progresses in the y direction after the debonding at the center (x, y)ϭ(0, W/2). Figure 12 shows the change of the occupancy of the debonded area (ϭratio of the debonded area (shown in block color in Figs. 10 and 11) to the whole area of the interface) with applied tensile strain for coat (i) (a) and (ii) (b). The lower the bonding strength, the larger became the occupancy of the debonded area of the coat (ii)-substrate interface, as shown in Fig. 12(b). For the coat (i)-substrate interface, as shown in Fig. 12(a), the occupancy of the debonded area also became larger for low bonding strength of the coat (ii)-substrate interface s (ii),int. .As indicated in Figs. 8 and 12(a), the preceding debonding of the coating with low interfaci...

show abstract

“…The grain size of the present sample was 10.3 mm in on average, 16) and its standard deviation was 5.3 mm.…”

Section: Morphology Observation Resultsmentioning

confidence: 58%

Analysis of Group-buckling and -debonding Behaviors of Galvannealed Coating Layer on Steel Substrates under Applied Tensile Strain

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…The coating layer exhibits multiple cracking under thermally induced stress during cooling from the heat treatment-to room-temperature due to the difference in thermal expansion between the coating layer and substrate steel. 1,[4][5][6][7][8][9][10] When tensile stress is applied, the multiple cracking progresses furthermore, 1,[4][5][6][7][8][9][10][11] as typically shown in Fig. 1, and then, as shown later, the coating layer is spalled.…”

Section: Introductionmentioning

confidence: 99%

“…1, and then, as shown later, the coating layer is spalled. 1,6,7,[12][13][14][15][16][17][18][19][20][21] Concerning the thermal and applied stress-induced multiple cracking of the coating layer, the authors [8][9][10][11] have recently measured the change of crack spacing with increasing applied strain e for two samples supplied as the common samples for the research group on structure and property of the coating on GA (galvannealed) steels, organized in The Iron and Steel Institute of Japan. One was the IF (Interstitial Free) steel substrate with 10 mm thickness-coating layer (hereafter noted as IF/10).…”

Section: Introductionmentioning

confidence: 99%

Crack Spacing Distribution in Coating Layer of Galvannealed Steel under Applied Tensile Strain

et al. 2007

Self Cite

View full text Add to dashboard Cite

“…10,12) In the present analysis, the crack spacing L in the x-direction (tensile direction) was taken to be 40 mm, and that W in the y-direc- tion (sample width direction) to be 80 mm, where Lϭ40 mm corresponds to the critical length at which buckling behavior of the coating layer were observed and Wϭ80 mm corresponds to the thermally induced critical crack spacing in the coating layer. 10,12,16) In addition, to detect the influence of the crack spacing in each direction on the interfacial debonding separately, the crack spacing L and W were varied as (L/mm, W/mm)ϭ (20,80), (40, 80), (60, 80) and (40, 40), (40, 60), (40, 80), respectively. The present specimens had been heated at 773 K for formation of the intermetallic compounds and cooled down to room temperature.…”

Section: Influence Of the Crack Spacing In The Coating Layer On The Pmentioning

confidence: 99%

“…1,2) As these materials are composed of brittle coating layer with low failure strain and ductile substrate with far higher failure strain, the coating layer exhibits multiple cracking perpendicular to the tensile direction, [3][4][5][6][7][8][9][10][11][12] followed by spalling, when tensile stress is applied externally. In our former work, the following spalling process, as schematically shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Crack Spacing in the Coating Layer on the Progress of Interfacial Debonding in Galvannealed Steel Pulled in Tension

2009

Self Cite

View full text Add to dashboard Cite

Relation between Cracking of Intermetallic Coating Layer of Galvannealed Steel Sheet and Grain Boundary of Substrate Steel

Cited by 5 publications

References 9 publications

Analysis of Group-buckling and -debonding Behaviors of Galvannealed Coating Layer on Steel Substrates under Applied Tensile Strain

Analysis of Group-buckling and -debonding Behaviors of Galvannealed Coating Layer on Steel Substrates under Applied Tensile Strain

Crack Spacing Distribution in Coating Layer of Galvannealed Steel under Applied Tensile Strain

Influence of the Crack Spacing in the Coating Layer on the Progress of Interfacial Debonding in Galvannealed Steel Pulled in Tension

Contact Info

Product

Resources

About