CVS Murthy1 P Mastanaiah1 Shaju K Albert2 Chitta Ranjan Das2 Dasarath Ram1 AK Bhaduri2

1 Defence Research and Development Laboratory, Hyderabad2 Indira Gandhi Center for Atomic Research, Kalpakkam

Development of Electron Beam welding for similar and dissimilar joints of 9Cr-1Mo Steel and Stainless Steel 316L(N)

Collaborative Project - IGCAR & DRDL

• EB Welding of SS316 LN to SS316L(N)• EB Welding of 9Cr-1Mo Steel to 9Cr-1Mo Steel• EB Welding of 9Cr-1Mo Steel to SS316L(N)• EB Welding of LAFM Steel to SS316L(N)

• Tensile Test• Charpy V-notch Impact Test• Bend (face/root) Test• Microhardness

EBW

9Cr-1Mo Steel to 9Cr-1Mo Steel

SS316L(N) to SS316L(N)

9Cr-1Mo Steel to SS316L(N)

EXPERIMENTATION

EB Welding Parameters

Beam Current 115mA

Gun Voltage 55kV

Welding speed 1 m/min

Gun to work distance

283mm

Focus Below the surface

Beam Current 95mA

Gun Voltage 55kV

Welding speed 1 m/min

Gun to work distance

283mm

Focus Below the surface

Beam Current 98 mA

Gun Voltage 55kV

Welding speed 1 m/min

Gun to work distance

283mm

Focus Below the surface

9Cr-1Mo Steel to 9Cr-1Mo Steel

SS316L(N) to SS316L(N)

9Cr-1Mo Steel to SS316L(N)

TENSILE PROPERTIES

0

100

200

300

400

500

600

700

800

900

Te

nsi

le S

tre

ng

th, M

Pa

Specimens

316L(N)SS base 9Cr-1Mo base 316L(N)SS-316L(N)SS join 9Cr-1Mo-316L(N)SS join 9Cr-1Mo-9Cr-1Mo join

0

100

200

300

400

500

600

700

800

Yie

ld S

tre

ng

th, M

Pa

Specimens

316L(N)SS base 9Cr-1Mo base 9Cr-1Mo-316L(N)SS join 9Cr-1Mo-9Cr-1Mo join 316L(N)SS-316L(N)SS join

0 5 10 15 20 25 30 35 40 45 50 55 60 65 700

100

200

300

400

500

600

700

En

gg. S

tren

gth

, MP

a

Total El, %

9Cr-1Mo base 316 L(N) SS 316L(N)-316L(N) SS join 9Cr-1Mo-9Cr-1Mo join 9Cr-1Mo-316L(N) SS join

•

MICROHARDNESS

-3 -2 -1 0 1 2 3 4 5

150

200

250

300

350

400

450 InterfaceInterface

9Cr-1Mo steel316L(N) SS

Har

dnes

s, V

HN

500g

Distance across the weld interface, mm

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.50

50

100

150

200

316L(N)SS316L(N) SS Weld metal

Ha

rdn

ess

, VH

N50

0g

Distance across the weld interface, mm

-1.0 -0.5 0.0 0.5 1.0 1.5

200

250

300

350

400

450

9Cr-1Mo steelInterafce

Weld metal

Har

dnes

s, V

HN

500g

Distance across the weld interface, mm

Charpy V-notch Impact Test

Type of EB Weld Impact Energy (J)

9Cr-1Mo steel to SS316LN

265

9Cr-1Mo steel to9Cr-1Mo steel

160

SS316LN to SS316LN > 300

Temperature : 21.50C

Bend Test

EB Welds of SS316LN and 9Cr-1Mo Steel • Three point bend test• Specimen prepared as per ASME B&PVC Code Section IX

Bend Test

Bend specimens - Dissimilar EB Weld

Macrostructure of weld of 9Cr-1Mo Steel

Macrostructures of Dissimilar Weld

• Lack of sidewall fusion / crack observed at the SS316 weld interface

SS EB weld

Macrostructure of EB Weld of SS316L(N)

Macro/Micro structures of SS316L(N) EB Welds

THANK YOU