中国工业检验检测网www.industryinspection.c

www.industryinspection.com QQ:596705349
Vol. 28 No. 5 28 5
Oct . 2009 HEBEI EL ECTRIC POWER 2009 10
:2009209203
TO FD
Re search on Dead Zone of TOFD Te st and Settlements
,,
(, 050021)
:TOFD
,,
TOFD ,
TOFD + A ,
TOFD ,TOFD
: TOFD ;;
Abstract :Because it should produce dead zone during testing
of Time2Of2Flight2Diffraction ( TOFD) , so as to cannot ex2
aminr the bug , this paper analyzes how to examine the dead
zone theoretically.
TOFD dead zone accords with through
test validated , so designsOFD + A mpulse reflect ultrason2
ic compound probe , suggestes to use compound test method
to fetch up the disadvantages of TOFD , and reduces the dis2
bennifit effect.
Key words : time of flight diffraction ( TOFD) ; dead zone ;
compound test
: T G115. 28
:B
:100129898 (2009) 0520026203
1
( Time Of Flight Diff rac2
tion , TOFD)
,,
TO FD
: ,
TOFD ,;
,
,
TOFD ;
;( POD)
;,
, TO FD
,
,TO FD
,
,
,,
1 TOFD
:(1975 - ) ,,,
,
中 国 工 业 检 验 检 测 网
www.industryinspecti
26
; TO FD
,
,
,,
,TO FD
2 ,,
,
TO FD 210 M Hz
,,
,
(
45 60 70 )
,,
TOFD 1
1 TOFD
(Lateral
© 1994-2010 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.net

www.industryinspection.com QQ:596705349
Vol. 28 No. 5 28 5
Oct . 2009 HEBEI EL ECTRIC POWER 2009 10
Wave ,L W) , Ddw(2) :
,2
(Backwall Wave ,BW) ,
Ddw = [ t 2 (cw + tp ) 2
- d 2 ] 1 2
4
- (2)
, :c ; tw ;
TOFD ,
,(Diff raction Signal)
,2
,, TOFD
,
2 TOFD ,
A
7 M Hz ,60 ,
5 900 m/ s ,100 mm ,32
mm ,,(1) (2) ,
Dds = 8. 3 mm ;
Ddw = 1. 6 mm
, TOFD
,
2. 2 TOFD
TOFD ,
,3
( ) ,3 4
5
www.industryinspecti
中 国 工 业 检 验 检 测 网
2 TOFD A
2 ,
,
,TOFD
,( RF)
,
,,
,
,
3 1 (:mm)
4 2 (:mm)
2 TOFD
2. 1 TOFD
TO FD ,
Dds
(1) :
Dds = [ (ctp ) 2
+ dctP ] 1 2 (1)
4
:c ; tp (10 %
) ; d 1/ 2
,
5 3 (:mm)
1 0. 5 mm 1 mm 2 mm 4 mm
,2
1 mm 2 mm 4 mm 6 mm 8 mm (
3 mm) ,3 2 mm 6 mm 8 mm
(2 mm) 20 mm ,
5 M Hz 1. 5
300 ns ,60 5 900 m/ s ,
27
© 1994-2010 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.net

www.industryinspection.com QQ:596705349
Vol. 28 No. 5 28 5
Oct . 2009 HEBEI EL ECTRIC POWER 2009 10
50 mm ,20 mm ,
Dds = 6. 7 mm ; Ddw = 1. 4 mm
1 ,(
) ,1
1 1 TOFD
/ mm
1 4
2 3
3 2
4 1
5 0. 5
2 ,
,2
2 2 TOFD
/ mm
/ mm
1 8 8
2 6 6
3 4 4
4 2 2
5 1 1
3 ,
,3
3 3 TOFD
/ mm
/ mm
1 8 8
2 6 6
3 2 2
, TO FD
8 mm ,2 mm ,
3 TOFD
, TO FD
,,
,,
TOFD
,2 ,TOFD
,TOFD
,,
TO FD ,
, , TOFD + A
,
,,,
,
TOFD
,TOFD + A
,6
6 TOFD + A
TO FD ,
,
中 国 工 业 检 验 检 测 网
www.industryinspecti
28
7 TOFD
,
4
7
,TO FD
,,
,,
,TO FD
,TOFD ,
TO FD + A
,
© 1994-2010 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.net
: