Separation in Wire spray (Metco 405)

[shabisyed]

Hi,
Can some one tell me what the cause of separation in wirespray.
When I spray Metco 405 wire on 4026 Al Alloy test piece I never have a separation problem.But when I spray Metco 405 wire on 5504 steel test piece with same parameter which I use for Al test piece ,some time there is no separation but some time I get separation.
Plz clear it.
Thanks

[loriolo]

Hola
This is a tipical 400 series martensitic steel, you must check temperature of the coating during spray, and be sure that roughness after blasting will be at least 30 µm HRz, and analize by a micro test the roughness profile, and another important think is to spray without preheating, you must heat the piece ( about 120 °C) before blasting, and spray it as fast as possible

[shabisyed]

Hi,
Thanks for reply.
But its 5504 steel test piece.during spray I always check temperature.it doest increase morethan 150 C. As you said dont preheat it and heat test piece before blasting.I never preheat the test piece but I never do heat test piece before Grit Blasting.I will try it.
what do you mean spray fast it as possible.
Do you mean spray with out giving cooling time?
Shabisyed

Hola
This is a tipical 400 series martensitic steel, you must check temperature of the coating during spray, and be sure that roughness after blasting will be at least 30 µm HRz, and analize by a micro test the roughness profile, and another important think is to spray without preheating, you must heat the piece ( about 120 °C) before blasting, and spray it as fast as possible

[loriolo]

of course you must perform spray before piece get cold, what about sand blast profile? and quality of the sand media?,