GF TM 160 ECO Betriebsanleitung Seite 30

9 Failure analysis
Feature
External state of joint
Feature
Internal state of joint
26
Operating instructions TM 160/250/315 ECO
Description
Welding flash too wide or too
narrow over part or all of weld
length, caused by, for example:
incorrect warming-up

time
incorrect heating-

element temperature
incorrect joint pressure

Non angular joint plane, leading
to variations in form of welding
flash over part or all of weld
length, cased by, for example:
edge preparation faults

incorrect welding unit

Description
No fusion or incomplete fusion
on joint faces, over part or the
whole of weld cross-section
caused by, for example:
contaminated

faces
oxidized joint faces

excessive reversal time

heating element

temperature too low
heating element

temperature too high
Hollow space in joint planes
caused by, for example:
Insufficient

pressure
Insufficient cooling

time
Isolated, numerously dispersed
or locally concentrated pores or
inclusions caused by,
example:
Vapour formation

during welding
Contaminated heating

element
Evaluation group
I II
See pg.14 See
DVS 2202-1 DVS 2202-1
guidelines guidelines
Permissible Permissible
if if
b1≥ 0,7 x b2 b1≥ 0,6 x b2
Evaluation group
I II
Not Not
Permissible Permissible
joint
Not Not
Permissible Permissible
joint
Permissible Permissible
if if
for
∆s ≤ 0.05 x s ∆s ≤ 0.10 x s
III
pg.14 See pg.14
DVS 2202-1
guidelines
Permissible
if
b1≥ 0,5 x b2
III
Not
Permissible
Not
Permissible
Permissible
if
∆s ≤ 0.15 x s