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information for citizens to secure access to information under the control of public authorities,
in order to promote transparency and accountability in the working of every public authority,
and whereas the attached publication of the Bureau of Indian Standards is of particular interest
to the public, particularly disadvantaged communities and those engaged in the pursuit of
education and knowledge, the attached public safety standard is made available to promote the
timely dissemination of this information in an accurate manner to the public.
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01 ' 5

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Step Out From the Old to the New

Mazdoor Kisan Shakti Sangathan

Jawaharlal Nehru

IS 3261 (1980): Carbon steel forgings for shipbuilding

industry [MTD 16: Alloy Steels and Forgings]

! $ ' +-
Satyanarayan Gangaram Pitroda

Invent a New India Using Knowledge

! > 0 B

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(Reaffirmed 2001)

Indian Standard
SPECIFICATION FOR
CARBON STEEL FORGINGS FOR
SHIPBUILDING INDUSTRY

( First Revision)
Steel Forgings Sectional Committee,
Chairman
SHBI B. IL ANANTHAXAMIAH

SMDC 21

Representing
WG Forge & Allied Industries Ltd, Thane,

Bombay

Members
SEBI B. CHATTERJE
SHBI S. K. DUTTA

Hindustan Aeronautics Ltd, Bangalore

Steel Authority
of India Ltd
( Bhilai
Plant ), Bhilai

Steel

SHBI B. M. K. BAJPAI (Alternate)

SHBI H. A. JAISINQHANI
Mahindra 8: Mahindra Ltd, Bombay
SARI A. R. RANADIVE ( Alternate )
SHEI R. JAYABA~AN
Hindustan Shipyard Ltd, Visakhapatnam
SHRI A. SESHA~IRI RAO ( Alternate )
SHRI R. C. JHA
Steel Authority
of India Ltd
( Alloy
Steels
Plant ), Durgapur
SHEI M. THAKUR ( Alternate )
JOINT DIRECTOR ( MET ) RDSO,
Ministry of Railways
LUCKNOW
SENIOR CEIZMIST & METALLUROIST, WHEEL & AXLE
PLANT, BAN~ALORE ( Alternate )
SHRI S. S. LAKKUNDI
Bharat Forge Co Ltd, Pune
SHRI K. C. GOGATE ( Alternuts )
Association of Indian Drop Forging and Stamping
SHBI P. MEHRA
Industries, Bombay
SEsr L~KEHEAN MISRA
Directorate General of Technical
Development,
New Delhi
SHRI K. C. P. NAIR ( Altcrnnte )
DB T. MUHHERJEE
Tata Iron and Steel Co Ltd, Jamshedpur
SHRI S. A. HAQUE (Alternate )
SBBI S. B. PAL
Ministry of Defence ( DGOF )
.
SHRI B. BANDYOPADHYA( Altemare 1
SERI K. PARTHASARATHY
Ashok Leyland Ltd, Madras
SHRI T. S. SUDARSHAN ( Alternate )
( Continued on page 2
@

Copyright

1981

INDIAN STANDARDS
INSTITUTION
This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and
reproduction in whole or in part by any means except with written permission of the
publisher shall be deemed to be an infringement of copyright under the said Act.

( Continuedfrom

page 1 )
Representing

Members

Central Boilers Board, New Delhi

Steel Authorrty
of India
Ltd ( Research
&
Development
Centre for Iron & Steel ),
Ranchi

SHRI C. M. PRASAD
DR G. RAI
DR S. K. MUKHFRJEE (
SHRI S. P. RAO
SHRI R. N. SAHA

Alternate)

WG Forge & Allied Industries Ltd, Thane, Bombay

Directorate
General of Supplies and Disposals,
New Delhi

SHRI B. DAS~UPTA ( Alternate )

Bharat Heavy Electricals Ltd
SHRI S. SAT~YANARAYANA
SHRI U. MOHAN RAO ( AItnnate I )
SHRI A. K. MITTAL ( Alternate II )
Ministry of Defence ( DGI )
SHRI M. K. SEN
SHRI A. PRASAD ( Alternate )
Hindustan Machine Tools Ltd, Bangalore
SERI SANJIT SEN
SHRI
A. SHANTHARAM ( Alternate )
National Institute of Foundry and Forge TechnoDB R. SHARAN
logy, Ranchi
SHRI N. P. SBKSENA C Alternate 1
SHRI S. R. SRINIVASAN .
. Shardlow India Ltd, Madras
SHRI R. S. K. RAMAN ( Alternate )
Heavy Engineering Corporation, Ranchi
SHaI A. D. SUR
SHRI S. MAZUMDAR ( Alternate )
Tata
Engineering
& Locomotive
Co
Ltd,
SHRI VENKATESAN
YTamshedour
.
Snar V. S. RAO ( Alternate )
Director General, IS1 ( Ex-ofiio Member )
SHRI C. R. RAMA RAO,
Director ( Struct & Met )
Secretary
SHRI JAQXOHAN SINQE
Assistant Director ( Metals ), IS1

Subcommittee

for Steel Forgings for General

Purposes, SMDC 21 : 1

Engineering

Convener
SHRI R. C. JHA

of India
Steel Authority
Plant ), Durgapur

Ltd

( Alloy

Steels

Mem hers
M. THAKUR ( Alternate to
Shri R. C. Jha )
ASSISTANT DIRECTOR ( MS )
SHRI

SHRI K. N. BAJAJ
DR A. Y. DE~ANI
SHRI C. R. GEOSH ( Alternate )
SHRI H. A. TAISIN~HANI

Research,
Designs and Standards Organization,
Lucknow
Metal Forging Pvt Ltd, New Delhi
Mukand Iron and Steel Works Ltd, Bombay
Mahindra

& Mahindra

Ltd, Bombay
( Continued on page 16 )

I$ : 3261-1980

Indian Standard
SPECIFICATION FOR
CARBON STEEL FORGINGS FOR
SHIPBUILDING INDUSTRY

( First Revision )
0.

FOREWORD

0.1 This Indian Standard ( First Revision ) was adopted by the Indian
Standards Institution on 10 December 1980, after the draft finalized by
the Steel Forgings Sectional Committee had been approved by the
Structural and Metals Division Council.
0.2 This standard was first published in 1966. On the basis of experience
gained in the production and use of forgings it has been decided to revise
the standard.
0.3 The following major modifications have been incorporated in this
revision:
a) Steel designation has been included in accordance with IS : 1762
( Part I )-1974*.
b) Provision for check analysis has been made.
c) Several additional
grades of carbon steel which are used for
production of forgings for shipbuilding
industry have been
included.
0.4 This standard contains clauses 4.2, 4.4 and 6.2.2 which permit the
purchaser to use his option for selection to suit his requirements.
0.5 For the purpose of deciding whether a particular requirement of this
standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with
IS : 2-1960t.
The number of significant places retained in the rounded
off value should be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standard covers the requirements
forgings required for shipbuilding purposes.

for 8 grades

*Code for designation

of steels: Part I Based on letter
tRules for rounding off numerical
values ( revised
),

symbols

of carbon

( &1 revision ),

steel

tS : 32619 19%0
2. TERMINOLOGY
2.1 For the purpose of this standard,
shall apply.
3. SUPPLY

the definitions

given in IS : 1956*

OF MATERIAL

3.1 General reauirements relating

shall conform to IS : 1387-1967t.

to the

SUDD~V
II

of carbon steel forgings

4. MANUFACTURE
4.1 Forgings shall be manufactured from killed steel produced by the
open hearth, electric or any other process approved by the inspecting
authority.
4.2 Forgings shall be brought as nearly as possible to the finished
_ _shape
and size by hot working and shall, where practicable, be so worked as to
cause grain flow in the most favourable
direction for resisting the
service stresses, which should be made known to the supplier by the
purchaser.
4.3 Except as specified in 4.3.1 to 4.3.3, and unless otherwise approved
by the inspecting authority, the maximum cross-sectional
area of any
part of the forgings ( as forged ) shall not exceed:
a) l/3 A where the length of any section is greater than its diameter,
and
b) 213 A where the length of any section is less than its diameter.
where A is average sectional area of the ingot or of the ingot after
upsetting, if such an operation is involved.
4.3.1 Turbine discs
made from cylindrical
bloom or billet,
The
stamped ) shall not be
which it was formed.

and other ring type or disc type forgings shall be

pieces which have been cut or machined from a
thickness of any part of a disc ( as forged or as
more than one-half of the length of the piece from

4.3.2 For rotor forgings of turbines, compressors and turbine driven

generators, the maximum cross-sectional area of any part of the forging
*Glossary of terms relating to iron and steel :
( Part I )-I976 General metallurgy, heat treatment and testing.
( Part II )-I976
Steel making
( Part III j-1975
Hot rolled steel products I excluding sheet and strip )
( Part VI j-1976
Forging ( including drop forging )
j-General requirements for the supply of metallurgical
materials (first revision ).

tS 1 3i41.
( as forged ) shall not trtceed one-half of the average
of the ingot or upset bloom.

cross-sectional

i9b0
area

4.3.3 For spindle forgings of the turbines, compressors, and turbine

driven generators, the cross-sectional area of any part ( as forged ) shall
not exceed one-third of the average cross-sectional area of the ingot
except at collars where the area is not to exceed two-thirds of the crosssectional area of the ingot.
4.4 The forgings shall be free from all defects and shall be finished to the
prescribed dimensions within limits as agreed to between the purchaser
and the supplier.
Defects in forgings shall not be repaired without the
previous sanction of the inspecting authority.
4.5 The shaping of forgings or thick slabs by flame cutting shall be
undertaken in accordance with the procedure approved by the inspecting
authority.
For machinery
parts that are subjected to cyclic stresses
during service, a depth of at least 12.5 mm shall be removed by
machining from flame cut surfaces.
5. CHEMICAL COMPOSITION

5.1 The composition of the carbon steel for large forgings having a ruling

section greater than 150 mm as well as for small forgings intended for
stressed applications when analysed in accordance with relevant parts of,
IS : 228* shall be as given in Table 1.
5.1.1 Check Analysis - The check analysis shall be conducted on
finished forging. The permissible deviation in case of check analysis from
the limits specified in Table 1 shall be as follows:
*Methods

of chemical

Part I

analysis of steels:

Determination
of carbon
by
O*l percent ( secondrevision )

Part II

volumetric

method

( for

carbon

>

Determination
of manganese
in plain carbon and low alloy steels
( Arsenitic method ) ( second reuzsion )
Part III
Determination of phosphorus ( Alkalimetric method ) ( second r&&n )
Part IV Determination
of carbon
( gravimetric
method ) for carbon >
0.1 percent ( second revision )
Part VIII
Determination
of silicon by gravimetric
method ( for silicon >
0.1 percent ) ( second
revision)
Part IX
Determination of sulphur in plain carbon
steels by evolution
method
( second revision )

Constituent, Percent

Permissible Variation, Percent, Max

y-----p
A_,_,,,__~
For sections
For sections
250 mms
250 mms to
or less
500 mma

Carbon:
up to 0.25
Over 0.25 up to and
including 0.50
Over 0.50
Silicon
Manganese
Sulphur
Phosphorus

ho.02
f003

f0*04
f0.05

f0.04
kO.03
AO.04
&0*005
&-0.005

-&O*OS
f0.04
f0.07
&O*OlO
fO*OlO

NOTE - Variations shall not be applicable

limits in several determinations in a heat.

both over and under the specified

5.2 Elements not specified in Table 1 shall not be added to the steel,
except when agreed to, other than for the purpose of finishing the heat
and shall not exceed the following limits:
Constituent
Nickel
Chromium
Copper
Molybdenum
Vanadium
Tin
6. HEAT

Percent
0.25
0.25
0.35
0.05
005
0.05

TREATMENT

6.1 At an appropriate

stage of manufacture, after completion of hot workshall be suitably heat-treated in a furnace

which shall permit the whole forging to be uniformly heated throughout
to the necessary temperature. If for any reason a forging is subsequently
heated for further hot working, the forging shall be re-heat-treated.
ing

operations,

each

forging

6.2 Heat treatment by one of the following methods

obtain the desired mechanical properties.

shall be applied to

6.2.1 The forgings shall be heated to a uniform temperature

upper critical point to refine the grain and shall then be:
a) fully annealed
manner, or

by cooling

slowly in the furnace

above the

in a uniform

IS : 3261- 1980
b) normalized

by cooling in still air, or

c) hardened by quenching
followed by tempering.
TABLE

in oil or by other recognized

1 CHEMICAL

method,

COMPOSITION

( Ciausc 5.1 )
CLASS

DESIGNATION
[seeIS:
1762
( PART I )-1974* ]

CONSTITUENT, PERCENT
~___--_-___-_~h__--_-___-__-~
Silicon
Manganese
Sulphur,
Carbon
Max
(3)

(4)

0.10

0.15

060

$0

0?5

OZO

0.15

815

25C8

oTo25
0.20

3OC8

3A

35C8

45C8

Phos;h;hxorus,
a

(6)

(7)

0.050

0.050

0.60

0.050

0.050

oG5
0.15

OZO
0.60

0.050

0*050

dp30
O-25

0?5
815

,fp,O
0.60

0.050

0.050

otp35
830

ot.035
0.15

otso
0.60

0 050

0.050

GO

6.035

0.40

0.15

GO
0.60

0,050

0.050

dp50
0.50

Otz5

5568

P,O
0.60

0.050

0.050

65C6

,GO
0.60

ofp35
0.15

Go
0.60

0.050

0.050

GO

0?5

GO

0.050

(1)

(2)

1A

15C8

2OC8

2A

(5)

o-15

NOTE lFor welded

construction
of the steel shall not exceed 0.22 percent.

ot
for ship

or machinery,

0.050
carbon

content

NOTE 2 - For turbine rotors, discs and spindles, turbine driven generators,
rotors and compressor rotors carbon content shall not exceed 0.45 percent.
NOTE 3 - Where mechanical
tests are required from forgings in either the
radial or the tangential direction or both, the sulphur and the phosphorus contents
of the steel shall not be more than 0.040 percent each.
NOTE 4 0.040 percent.

For gear wheels the sulphur or phosphorus

content

NOTE 5 - When the steel is aluminium-killed

or killed with
and silicon, the requirements of silicon content shall not apply.
NOTE 6 - When the steel is made
shall not exceed 0809 percent.
*Code for designation

by oxygen

process,

of steels: Part I Based on letter symbols.

shall not exceed

both aluminium

the nitrogen

content

IS : 3261-

1980

6.2.1.1 If having regard to the carbon content, the ruling section of

the forging is equal to or greater than the equivalent
diameter
given
below,
the normalizing
treatment
shall be followed
by a tampering
( stress-relieving
) treatment.
Equivalent
Diameter
mm

Carbon, Percent
r_______h--___--~
Over

Up to and
including

Cl*40

0.50

0.35

0.40

500

0.30

0.35

700

O-25

0.30

900
1 000

400

0.25

Other forgings may be tempered

at the option of the forgemaster.
6.2.2 Treatment
agreement
between
7. NUMBER

( stress relieved

) after normalizing

given in 6.2.1 (c) shall not be adopted

the supplier and the purchaser.

without

prior

OF TESTS

7.1 For the purpose of mechanical

tests, sufficient
material
of not less
than the sectional dimensions
of the body shall be formed integral with
This material
shall not be removed from the forging until the
forging.
heat treatment is completed
and the forging as well as the test material
stamped for identification
by the inspection
authority,
except where an
alternative
procedure has been specially approved.
7.2 For general
carbon
steel forgings
of large cross-section
at least
one tensile and one cold bend test piece shall be taken from each forging
( or multiple forging ). In case of forgings or multiple forgings exceeding
both 3 000 kg in weight and 2.44 m in length, one tensile and one cold
bend test piece shall be taken from each end of each forging or multiple
forging.
7.3 For small forgings
testing may be adopted.
test and inspection
in
treatment
batch.

where quantity
production
is involved,
batch
In such cases, forgings shall be presented
for
groups
of the same cast and the same heat

7.4 For forgings of turbine rotors and spindles, turbine driven generators,
rotors and compressor
rotors, at least one longitudinal
tensile and one
cold bend test piece shall be taken to represent
the material
of each
( or multiple
forgings ) exceeding
both 3 000 kg in weight
forging

t$ : 3261- 1980
and 1.83 m in length
test piece shall be taken

not less than one tensile and one cold

from each forging ( or multiple forging ).

bend

7.4.1 For rotor forgings

of all main propulsion
machinery
and of
auxiliary turbines exceeding
1 500 SHP tangential
and where dimensions
permit, radial tensile and bend test pieces shall also be taken from the
end of the body corresponding
to the top end of the ingot.
7.4.2 For each turbine disc, at least one tensile and one bend test piece
shall be cut in a tangential
direction from material at the hub.
7.5 For single gear wheel or wheel-rim
forgings greater than 2.44 m in
diameter
or 3 000 kg in weight
and for multiple
forgings,
one set
of circumferential
test pieces consisting of one tensile and one bend test
piece shall be taken from each end of the forging from the positions diametrically opposite, provided that in the case of multiple forgings all the
portions cut from it are heat treated together.
For smaller single wheels
or rims, a set of circumferential
test pieces shall be taken from one end of
the forging.
8. MECHANICAL
FORGINGS
8.1

Tensile

TESTS

FOR

GENERAL

CARBON

Test

8.1.1 Tensile test shall be carried

in accordance
with IS : 16C8-1972*.
8.1.2 The tensile strength
shall be as given in Table 2.

and

out on standard
percentage

test

elongation

8.1.2.1
Yield stress shall be determined
when
For crank
purchaser for certain machinery
forgings.
yield stress shall be 210 N/mms.
8.2

STEEL

pieces prepared
of the

forgings

so specified by the
webs, the minimum

Bend Test

8.2.1 Bend test pieces shall be

either 25 mm wide x 20 mm thick,
strength of the steel does not exceed
thick, where the specified minimum
The edges of the test pieces may be
1.5 mm in each case.
8.2.2
*Method
tMethod

machined
to a rectangular
section of
where the specified minimum tensile
560 N/mm2 or 20 mm wide x 10 mm
tensile strength
exceeds 560 N/mmz.
rounded to a radius of not more than

Bend test shall be conducted

in accordance

with IS : 1599-1974t.

for tensile testing of steel products

(f;rs~ reuision ).
for bend test for steel products
other than sheet, strip,

wire and

tube,

IS : 3261.1960
TABLE

TENSILE

TEST

( Clause 8.1.2 )
ACTUAL TENSILE
STRENGTH N/mm=

ELONGATIONON 5.65 2/ So PERCENT, MINJXUM

h-----,-----~
r--------Longitudinal or in the
Transverse or Across the
Direction of Principal
Direction of Principal
Grain Flow
Grain Flow

Over 340 up to 390

,*

390

,,

440

27

22

25

21

,,

440

,,

490

23

19

,,
,,

490
540

>, 540
,, 590

22

18

20

16

,,

590

,,

640

18

14

,.

640

,,

690

16

12

NOTE 1 79 N/mma.

Specified range of tensile strength

for any forging

shall not exceed

NOTE 2 - Where tensile test pieces are taken from each end of a forging
or multiple forging, the test results shall not vary by more than 63 N/mmS.

8.2.3 Bend test pieces shall withstand, without fracture, being bent
cold through 180 round a former having diameter not greater than that
specified in Table 3 according to the tensile strength.
The test pieces
shall be bent over the thinner section.
TABLE

TENSILE STRENGTH
N/mm2

up to 490
Over

INTERNAL

DIAMETER

MAXIMUM INTERNAL DIAMETER OF BEND

_-----__*----__---_-~
r--Transverse or Across the
Longitudinal
or in the
Direction of Principal
Direction of Principal
Grain Flow
Grain Flow
213 t

490 up to 590

Over 590

,,

OF BEND

690

Over 690

14 t
2t

2t

4t

3t

5t

t = thickness of test piece.

8.2.4 Where a number of individual forgings of the same type are

produced, a system of batch testing may be adopted by the inspecting
authority.
In such cases, forgings are to be presented for test and
inspection in groups of the same cast and the same heat treatment batch.
10

ts t 3i6i

19&o

8.2.4.1 Where a system of batch testing is adopted, the hardness of

each forging is to be determined including those from which material is
to be cut for the provision of tensile and bend test pieces. The hardnesses
of the forgings shall comply with a specification
approved by the
inspecting authority before manufacture of the parts.
9. MECHANICAL
TESTS FOR CARBON STEEL FORGINGS
FOR
TURBINE
ROTORS,
DISCS
AND
SPINDLES,
TURBINE
DRIVEN GENERATORS,
ROTORS AND COMPRESSOR
ROTORS
9.1 Tensile

Test

9.1.1 Tensile test shall be carried out on standard test pieces prepared
in accordance with IS : 1608-1972*.
For longitudinal and transverse test
pieces, the cross-sectional
area shall not be less than l-6 ems and for
radial test pieces not less than 0.65 ems.
9.1.2 The percentage elongation, when determined
IS : 1608- 1972*, shall be as given in Table 4.
TABLE
SPECIFIED MINIWJM
TENSILE STRENGTH

N/mm*
440
490
540
590
690
780
880
980

PERCENTAGE

ELONGATION,

MINIMUM PERCENTAGE
ELONGATIONFOR GAUQE
LENQTH OF 5.65 l/s
_-.____A-__--~
I
R
T
L
24
23

20
19

17
16

22
19
17
16
15
14

17
16
14
12
11
10

15
14
12
10
-

in accordance

with

Min

MAXIMUM DIAMETEROF
FORMERFOR BEND TEST
r-------___~
180
L
2t
2t
22/3:
4t
4t
4t
6t
6t

1500
T
2t
2t
22/31
4t
4t
4t
6t
6t

120
R
2t
2t
22/3t
4t
4t
-

9.1.2.1 Unless otherwise specified and approved, the yield stress or

0.5 percent proof stress of steel, shall not be less than 50 percent of the
actual tensile strength for normalized material.
9.1.2.2 The reduction of area at fracture
test pieces shall not be less than:
a) 95 percent for longitudinal
b) 90 percent for transverse

as determined

test,
test, and

c) 20 percent for radial test.

*Method for tensile testing of steel products (Jirst rmision).

11

on tensile

9.2 Bend Test

9.2.1 Bend test pieces shall be machined to a section of 20 mm
by 10 mm. The edges of the test pieces may be rounded to a radius of
not more than 1.5 mm. Bend test shall be conducted in accordance with
IS : 1599-1974*.

9.2.2 The test pieces shall be bent cold without fracture through 180
for a longitudinal test piece; 150 for tangential test piece; and 120 for a
radial test piece.
The maximum diameter of the former over which the
bend test shall be conducted is given in Table 5.
TABLE

MAXIMUM

SPECIFIED TENSILE
STRENQTB, Min
N/mm2

430
450
530
620
700

GEAR

WHEELS

10.1 Tensile

OF FORMER

FOR BEND TEST

DIAMETER OF FORMER, MAXIMUM

h---_-_-----~
r----------Longitudinal
Tangential
Radial

(1)

10. MECHANICAL

DIAMETER

TESTS

HO0

150

120

(2)
20
20
25
40
40

(3)
20
20
25
40
40

(4)
20
20
25
40
40

FOR

CARBON-STEEL

FORGINGS

FOR

Tests

10.1.1 Tensile test shall be carried out on standard test pieces, prepared
in accordance with IS : 1608-1972.

10.1.2 The yield stress and percentage elongation

tensile test pieces shall be as given in Table 6.
10.1.3 Unless otherwise specified and approved,
steel shall not be less than that given in Table 6.

after fracture

of

the yield stress of

10.2 Bend Test

10.2.1 Bend test pieces shall be machined to a rectangular
section of
25 mm wide x 20 mm thick for steel not exceeding 620 N/mm2 tensile
strength and 20 mm wide x 10 mm thick where the tensile strength
exceeds 620 N/mm*. The edges may be rounded to a radius of
1.5 mm in each case.
*Method for bend test for steel products other than sheet, strip, wire and
(first revision ) .
fMethod
for tensiIe testing of steel products (JirJt revision ).

tube

&S : 326X-

10.2.2 Bend

test

shall

conducted

be

in

accordance

with

1980

IS : 1599-

1974*.
10.2.3 The test pieces shall withstand without fracture, being bent cold
through
180 over a former
having
a diameter
not greater than that
specified in Table 6. They shall be bent over the thinner section.
TABLE

MECHANICAL
PROPERTIES
FORGINGS FOR GEAR
(

STEEL

Carbon cr

HEAT
TREATMENT

CZ4USdS

Normalised
tem-

carbon

and

manga-

peredor

nese

hardened

10.12, 10.1.3

MIXUMUM
YIELD
STRESS
N/mm2

oil
and

tempered.
NOTE - Circumferential
properties.

FOR CARBON
WHEELS

STEEL

102.3 )

and

SPECIMINIMUM
ELONQATION
PERCENTAGE
FIED
MINI5.65 4~;
r___h_--T
MUY
Trans
TENSILE
Long
STRENQTH
(See
Note )
N/mm
19

BENDTEST
MAXIMUM
DIA&fETER OF
FORMER
r___A-__~
Trans
Long
( See
Note )
1113t
2/3t

225

440

23

245

490

22

18

2/3t

1u3t

275

540

20

16

2r

295

590

18

14

2t

325

640

17

12

2t

4t

345

690

16

11

2t

4t

test pieces

from rim forgings

are to give longitudinal

10.3 Hardness
Test - Except in special cases where prior approval is
taken from the inspecting
authority,
hardness test shall be made on all
forgings after machining
to 6.5 mm over the finished diameter after heat
treatment.
The impressions shall be taken at each end of two diameters
at right angles in three different positions over each toothed portion of the
. .
The
forging
shall be considered
sufficiently
uniform
if the
%gRz,e
between the highest and lowest value does not exceed 20 in
Brine11 numbers
or their equivalent
for steels of tensile strength not
30 in Brine11 number
for steels over
exceeding
620 N/mma and
620 N/mm*.
11.

RETESTS

11.1 Should

either a tensile or bend test fail to pass the tests specified in

the standard,
two further
tests shall be made from the same forging
in respect of each failure. Should the results of both these additional
tests
are satisfactory,
the forgings shall be accepted provided that in other respects they fulfil the conditions
of the specification.
If any of these
additional
tests does not give satisfactory
results the forgings represented
*Method for bend test for steel products
(&St reuision ).
13

other

than

sheet,

strip,

wire and tube

Is : 3261 = 1980
may be re-heat-treated
and presented to the inspecting authority for
further testing.
If any test, made after the permissible number of heat
treatments, fails to meet the requirements of the standard, the forging
shall be liable to rejection.
No forging shall be re-heat-treated
more
than twice.
12. INSPECTION

AND MARKING

12.1 General Carbon Steel Forgings

12.1.2 The inspecting authority shall examine each forging.
In the
case of forgings for crankshafts which have finished pin or journal
in excess of 510 mm diameter, the supplier shall carry out an ultrasonic
test in the presence of the inspecting authority. In the event of any forging
proving unsound during subsequent machining,
erection of trials, such
forging shall be rejected notwithstanding any previous certificate of satisfactory test and inspection.
12.1.2 Every forging, after it has withstood satisfactorily the prescribed
tests and inspection, shall be clearly marked by the inspecting authority
indicating that the forging has complied with the requirements of the
standard.
12.1.2.1 When forgings are ordered in fully machined condition, the
identification marks shall be transferred by the inspecting authority after
full machining.
12.2 Turbine Rotors, Discs and Spindles,
tor Rotors and Compressor Rotors

Turbine

Driven

Genera-

12.2.1 Rotor forgings for propulsion machinery

and for auxiliary
turbines exceeding 1 500 SHP shall be hollow bored for internal examination. The surfaces of the bores shall have a fine, smooth-finish. Suitable
optical instrument shall be provided for examining the bores. Alternative
methods for detection of internal soundness of the forgings may be
accepted, if thought fit by the inspector.
12.2.2 The end faces of rotor forgings shall
smooth finish for the purpose of examination.

be machined

to a fine

12.2.3 The end faces of the boss and the bore surface of each turbine
disc shall be machined to a smooth finish and examined by a magnetic
crack detection method.
12.2.4 All solid forged HP steam and gas turbine
main propulsion service where the inlet steam or gas
400C shall be subjected to at least one thermal
stability test shall also be carried out for forgings
welding.

14

rotors intended for

temperature exceed
stability test.
The
of rotors joined by

12.2.5 The details of the test to be carried out shall be furnished by

the inspecting authority and the particular mention shall be made in the
specification for carrying out such tests by the purchaser.
12.2.6 In the case of rotor failing to meet the requirements of a
thermal stability test, the rotor is deemed unacceptable.
Proposals for the
rectification
of thermal instability of a rough machined rotor shall be
submitted to inspecting authority for special consideration.
12.2.7 Every forging, after it has withstood satisfactorily the prescribed
tests and inspection, shall be clearly marked by the inspecting authority
indicating that the forging has complied with the requirements of this
standard.
When forgings are ordered in fully machined condition, the
identification
marks shall be transferred by the inspector after full
machining.
12.3 Gear Wheel Forgings
12.3.1 The inspecting authority shall examine each forging.
For such
examination, sulphur prints shall be taken from the ends of the wheel rim
to varify that the steel is clean and free from harmful segregation.
Other
optional test like magnetic crack detection may be conducted subject to
mutual agreement between the inspector and the supplier.

12.3.2 The teeth of all surface and case hardened

examined for cracks and other imperfections by magnetic
method.

wheel shall be
crack-detection

12.2.3 Every forgings, after it has withstood satisfactorily the prescribed

tests and inspection, shall be clearly marked by the inspecting authority
indicating that the forging has complied with the requirements
of
this standard.
When forgings are ordered in fully machined condition,
the identification marks shall be transferred by the inspecting authority
after full machining.
12.4 The forgings may also be marked with the IS1 Certification

Mark.

The use of the IS1 Certification Mark is governed by the provisions of

the Indian Standards
Institution ( Certification Marks ) Act and the Rules and
Reguiations made thereunder.
The ISI Mark on products covered by an Indian
Standard conveys the assurance that they have been produced to comply with the
requirements of that standard under a well-defined system of inspection, testing and
quality control which is devised and supervised by IS1 and operated by the
producer.
IS1 marked products are also continuously checked by IS1 for conformity
to that standard as a further safeguard. Details of conditions under which a licence
for the use of the IS1 Certification
Mark may be granted to manufacturers
or
processors, may be obtained from the Indian Standards Institution.
NOTE

15

( Continuedfrom page 2 )
Representing

Members

Bharat Heavy Electricals Ltd, Hardwar

SARI R.N. MAHENDRU
SERB A. K. SHARMA
( AbnatC)
Heavy Engineering Corporation Ltd, Ranchi
Sam
S. MA~UMDAR
Bihar Alloy Steels Ltd, Ranchi
SHRI K. B. MOWLIE
Mahindra Ugine Steel Co Ltd, Bombay
DR R. V. PATHY
WG Forge &zAllied Industries Ltd, Thane, Bombay
SHRI S. P. RAO
SRRI B. K. ANANTHARAMIAB ( Alternate )
Association of Indian Drop Forging and Stamping
REPRESENTATIVE
Industries, Bombay
Bharat Forge Co Ltd, Pune
REPBESENTATIVE
All India Metal Forging Association, New Delhi
Sanr VIJAY KUMAR
SHRINARENDBAKUYAB
(AltcrMte)
Tata
Engineering
&
Locomotive
Co
Ltd,
SHRI M. VENKATESAN
Jamshedpur
SJXRI V. S. RAO ( Altmate )

16