y

C
/
O
C
N
h
Ta
Company
In Name :- ZF Steering Gear (I) Ltd
N
Plant
g location :- Pune
U
e
Customer
O name :
Confidentiality
U
A Level :- Confidential
Su
tSTRUCTURE ANALYSIS (STEP 2)
Ih
M
o
P
r
R
i1.Process Item 2.Process step
O
zSystem
V
a
S

Et
### M
i
Eo
N
n
T1.Heat
(Treatment 2. Washing
AShot Blasting
s3.Straightening

a
p
p
###
l
i
c1.Heat
aTreatment 2. Preheating
bShot Blasting
l3.Straightening
e
)

###
###

1.Heat
Treatment 2. Sealed Quench Furnace for
Shot Blasting Carburising,Diffusion &
3.Straightening Hardening

###

1.Heat
Treatment 2.
Shot Blasting Tempering
3.Straightening

1.Heat
Treatment 2. Charge preparation
Shot Blasting
3.Straightening
 1.Heat
Treatment 2. Charge preparation
Shot Blasting
3.Straightening
 1.Heat
Treatment 2.
Shot Blasting Shot blasting
3.Straightening
###

1.Heat
Treatment 2. Straightening( Only for
Shot Blasting P.steering worms)
3.Straightening
###
###
###
###
###
) Ltd

FUNCTION ANALYSIS (STEP 3)

3.Process work element 1.Function of the 2.Function of the

process item process step
WASHING M/C
1.Operator

2.Air Pressure
3.Washing Free from oil , dust As per required
Chemical and foreign Specification.
particles.
4.Measuring Instruments

5.Quenching Oil
6.Process Cycle
PRE-HEATING FURNACE
1.Operator

2.Air Pressure To attain desired

temperature before As per required
loading in SQF. Specification.
3.Measuring Instruments

4.Process
Cycle
Case depth

SQF
1.Operator
2.Air
SQF
1.Operator Micro-structure
2.Air
Pressure
As per required
3.Measuring Specification.
Instruments

4.Process Cycle Core strength.

5.Jigs & Fixture

Tempering Hardness
1.Operator
2.Air
Pressure As per required
Specification.
3.Measuring Microstructure.
Instruments

4.Process Cycle

Systematic
Charge preparation arrangement of As per required
components as per Specification.
batch size.
 Systematic
Charge preparation arrangement of As per required
components as per Specification.
batch size.

Clean centers.
 Shot blasting
1.Operator
2.Air
Pressure As per required
Specification.
3.Measuring
Instruments Damage free
centers.
4.Process Cycle
 Straightening( Only
Bend free
for P.steering worms)
1.Operator
As per required
2.Hydraulic Load Specification.

3.Measuring Gauge

Crack free.
Crack free.
PFMEA Start Date : 14/12/2003
PFMEA Revision Date : 03.02.2021
Cross-Functional Team :RMP/RDS/BRB/SPS/VLB
FMEA DATE (ORIG.) : FMEA DATE(Org) : 14/12/2003 RE

3.Function of the process work element

Bath concentration.
Bath temperature.
Bath agitation.
Oil free bath

Change bath content in every three month

Temperature
Time

Air circulation.

Time
Temperature
Atmosphere circulation
Carbon potential (MV) control.
Nitrogen pressure.

Sufficient flow of cooling water.

Temperature

Time

Air circulation.

. Uneven case depth and surface hardness

Reduced life of the component.

Reduced life of the component.

Direction of shot flow.

Time.

Dust collection.

Shot diameter.
Adequate shot flow.
Fixture of starightening m/c

Dial gauge

Skilled Operator
 003
21
/BRB/SPS/VLB
ATE(Org) : 14/12/2003 REV.N0:19

FAILURE ANALYSIS (STEP 4)

Severity
1.Failure Effects (FE) (S) of FE 2.Failure mode (FM) of the
process step

Components with oil and Components with oil and

dust dust

SQF Operational Temp. SQF Operational Temp. will

will drop and gas failure drop and gas failure will be
will be occured occured

Improper case depth. Improper case depth.

Improper
microstructure Improper microstructure

As quench hardness As quench hardness

variation. variation.

Low/High hardness Low/High hardness

Improper Microstructure Improper Microstructure

Dense charge Dense charge

Loose fixture. Loose fixture.

 Loose fixture. Loose fixture.

Presence of scales Presence of scales

Presence of no carb Presence of no carb paste
paste residue residue
Bend Job Bend Job

Grinding unclean due to Grinding unclean due to it

it will damage mating will damage mating
component surface. component surface.
 REV. DATE: 03.02.2021

3.Failure cause (FC) of the work element

Improper bath
Concentration.
Temperature.
No agitation.

No Drying

Temperature.

Controlling instruments Failure

Less / more carburising time.

Low / high carburising temp.(power failure)
Low / high carbon potential.
Improper circulation of atmosphere.
Less soaking time.
Less hardening temperature.
High quench oil temperature.
No oil agitation.
oil level.
Reverse dire- ction of agitation.
Temperature.

Controlling instruments Failure

Trained Manpower
 Trained Manpower

Improper direction of shot flow.

Lesser cycle time for shot- blasting.

Improper dust collection.

Insufficient flow of shots.

Improper shot diameter.

Improper setting of the shot cage

Dense placement of jobs.

Improper Load

Dial gauge wrong reading

Fixture Alignment
RISK ANALYSIS (STEP 5)

Current Prevention Control (PC) of FC

Sheduled PM of machine
Daily Concentration Inspection & top up washing chemical if required
Maual mode oil cleaning from bath

Calibration Of Controllers and Instruments

Sheduled PM of machine

Calibration Of Controllers and Instruments

Sheduled PM of machine
Calibration Of Controllers and Instruments
Operator Skill development
Calibration Of Controllers and Instruments

Process Validation

Calibration Of Controllers and Instruments

Operator Skill development

Calibration Of Controllers and Instruments

Customised fixtures

Rigid fixture.
Adequate spacing.

Visual inspection before doing

Vertical placement of components.

Automatic temp cont. with excess

temp. safety.

Frequent monitoring and recording of process parameters.

Top - downwards,Bottom - Upwards

Cycle timer with alarm.

Prev. maint.

Topping up the

shot level and cleaning the mesh.

Standard grade of S 230/s170 shots.

Customised fixtures and proper placement of jobs.

Top - 11 O`clock Bottom - 7 O`clock

Visual check.

Gradual load application

Locating centers .

Proper spacing between support blocks

Prepeatability of dial
Anvil diameter
Occurrenc
e (O) of FC

FM
Current Detection
Controls (DC) of FC or
Dtection
(D) of
FC/FM
PFMEA AP

Special
characteri
stics

Filter
code
(Optional)
F-MED-83505-en
Ver 1.0
4/1/2018

OPTIMIZATION (STEP 6)

Responsible Target
Preventive Detection person's Completion Status
Action Action Name Date
 Evidence
Action Taken
Date
with pointer to Completion
Severity
(S)
Occurrenc
e (O)
Detection
(D)

Special
Product
Characteri
stic
PFMEA AP

Remarks
 FMEA data sheet of 8033 piston machining
Old fmea New fmea
Operation no. Process step Faliure mode causes Faliure mode
100 Facing & Boss OD turning 2 3 6
110 Carburised Boring 4 5 9

M-bore drilling 5 12 7
Counter bore operation 1 8 9
Trippaning operation 1 2 8
4.1 slot operation 0 0 7

Eye Hole drilling Operation 0 0 6

Eye Hole M5 Tapping

1 1 7
Operation

Eye Hole Spot Facing

120 (2nd setup) Operation 1 3 6

Slotting operation 2 4 12
Drilling for M5 tapping 0 0 8

M5 tapping in M-bore 1 1 7
Drilling for M-12 tapping
1 2 7
operation
M12 Tapping 1 2 6
Outlet hole Drilling. 3 3 6
6.2 end mill operation 0 0 4
Center Hole machining 1 3 6

Pocket milling 1 1 5
Inlet hole drilling 1 1 6

130 (3rd setup) Cross hole drilling 3 3 5

Total 29 54 137
ining
New fmea
causes
14
25

20
26
19
23

18

19

16

29
21

18

20

16
14
9
15

12
22
14
370