November 2020 Volume 2

0.2

Carbides-Free Bainitic Ferrite – 4.5%

111

0

Frequ

0 20 40 60 80 100

IQ

( C ) Figure 39: EBSD-IQ analysis for the SLM 4340 cooled at ( A ) 1C/min, ( B ) 20C/min and ( C ) 100C/min after deformation.

001 FORGING RESEARCH AND TECHNOLOGY 101

Figure 38: Inverse Pole Figure (IPF), and grayscale IQ-map and grain boundary distribution, for the SLM 4340 cooled at ( A, B ) 1C/min, ( C, D ) 20C/min and ( E, F ) 100C/min; after deformation.

The same process was conducted for the wrought 4340. Figure 40 and Figure 41

show this analysis for all the samples analyzed after deformation.

0 0.1 0.2 0.3 0.4 0.5

MA – 14.2% Pearlite – 23.3% Ferrite – 62.5%

Frequency

0 20 40 60 80 100

IQ

( A )

0.3

MA – 3.5% Martensite – 25.7% Granular Bainite – 34.5% Bainite – 36.6%

0.2

( A )

( B )

0.1

0

Frequency FORGING RESEARCH

0 20 40 60 80 100

IQ

( B )

0.6

Martensite – 79.6% Granular Bainite – 15.9% Carbides-Free Bainitic Ferrite – 4.5%

0.4

FORGING RESEARCH

0.2

( C )

( D )

0

Frequency

0 20 40 60 80 100

32

IQ

Figure 39: EBSD-IQ analysis for the SLM 4340 cooled at (A) 1C/min, (B) 20C/min and (C) 100C/min after deformation. The same process was conducted for the wrought 4340. Figure 40 and Figure 41 show this analysis for all the samples analyzed after deformation. ( C ) Figure 39: EBSD-IQ analysis for the SLM 4340 cooled at ( A ) 1C/min, ( B ) 20C/min and ( C ) 100C/min after deformat on. The same process was conducted for th wrought 4340. Figure 40 and Figure 41 show this analysis for all the samples analyzed after deformation.

33

( E )

( F )

111

101

001

Figure 40: Inverse Pole Figure (IPF), and grayscale IQ-map and grain boundary distribution, for the Wrought 4340 cooled at (A, B) 1C/min, (C, D) 20C/min and (E, F) 100C/min; after deformation. Figure 40: Inverse Pole Figure (IPF), and grayscale IQ-map and grain boundary distribution, for the Wrought 4340 cooled at ( A, B ) 1C/min, ( C, D ) 20C/min and ( E, F ) 100C/min; after deformation.

0 0.1 0.2 0.3 0.4

( A )

( B )

C-rich constituents – 3.3% MA – 5.6%

Pearlite – 20.3% Ferrite – 70.8%

Frequency

0 20 40 60 80 100

IQ

( A )

0.6

0.4

Martensite – 81.5% Bainite – 18.5%

0.2

0

Frequency

0 20 40 60 80 100

IQ

( C )

( D )

( B )

FIA MAGAZINE | NOVEMBER 2020 98

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