Dear all,

we are doing hardfacing in seat area for ic engine valves, please tell me the way out to find blow holes & bonding defects detection by Ndt Method, who is making the equipment.

we are doing this by Pta process, also tell me what could be possible cause for this defect

guru

Hi Guru

to the Surface Engineering Forum.

Other than dye penetrant crack testing, which will only show defects that break the surface I think ultra-sonic, thermography, (possible eddycurrent) and radiography type methods will be needed to detect internal defects.

I will leave your other questions to those more experienced with PTA (plasma transfer arc) welding process.

Gordon Wrote:Hi Guru

to the Surface Engineering Forum.

Other than dye penetrant crack testing, which will only show defects that break the surface I think ultra-sonic, thermography, (possible eddycurrent) and radiography type methods will be needed to detect internal defects.

I will leave your other questions to those more experienced with PTA (plasma transfer arc) welding process.

hi everybody
stellite on pta can be tested by uv
i welded stellite on seats for oil for long time,pta is very sensible machine,everything can cause problems
only the position of powder feeder can be determinante in quality of welding
pre heat is very important,it depend the size you are welding ,we cant recomand any temperature
gas must be controled :arg,hel
dust extraction mustn t make turbulence otherwise you will have some problems :deposition of burnt particule on welding parts
i hope this can help

hvofhamid Wrote:

Gordon Wrote:Hi Guru

to the Surface Engineering Forum.

Other than dye penetrant crack testing, which will only show defects that break the surface I think ultra-sonic, thermography, (possible eddycurrent) and radiography type methods will be needed to detect internal defects.

I will leave your other questions to those more experienced with PTA (plasma transfer arc) welding process.

hi everybody
stellite on pta can be tested by uv
i welded stellite on seats for oil for long time,pta is very sensible machine,everything can cause problems
only the position of powder feeder can be determinante in quality of welding
pre heat is very important,it depend the size you are welding ,we cant recomand any temperature
gas must be controled :arg,hel
dust extraction mustn t make turbulence otherwise you will have some problems :deposition of burnt particule on welding parts
i hope this can help

hi man
seats I presum you weld 2" 3" 4" 5" 6" and 9"
2" preheat 110° 22 V first pass 150 A 2nd 145A
3" preheat 120-140° first pass 165A 2ND 150 A
4" 140-160° 165 2ND 155A
5" 180-200° 175 2ND 160
6" normal same temperature than 5"
large piste 200-220° 175A 2ND 160A