4130 steel protection
4130 steel protection
(OP)
Hello!
I'd like to know an aeronautical process/treatment to protect from corrosion AISI 4130 tubes.
Is there anyone can help me?
Thank you
I'd like to know an aeronautical process/treatment to protect from corrosion AISI 4130 tubes.
Is there anyone can help me?
Thank you





RE: 4130 steel protection
Thermal environment is important. If it's part of an engine mount how hot will it get? Cad/zinc are a bit limited.
Have to make sure the inside is drained (a hole at least 6 mm diameter is advisable).
Make sure any fastener holes, etc., are protected, and any fastenings should be wet assembled.
If it's a part for a major like A or B (or Embraer, Bombardier, etc.) they'll have their own standard protection requirements.
4130 sees only limited use due to its corrodibility, limited ruling section (about 1/2"), relatively poor strength/weight and relatively low toughness.
RE: 4130 steel protection
Do you suggest an alternative material?
Thanks a lot
RE: 4130 steel protection
Depends on what's driving the sizing. If it's beam-column static stability/strength then low alloy steel is a pretty good choice, as is a round tube. If there's a bigg-ish influence of damage tolerance (tension with the presence of cracks) then a tougher alloy (like 4340) would save some weight compared with 4130 at the same strength.
Also depends a bit if it's desirable for the part to be welded. This would make quite a nice little strut and would count against higher carbon steels like 4x35 and 4x40.
An awful lot of the cost and weight will likely be in the end-fittings/connections (depends on overall length). It's there that Al alloy might show a benefit versus steel.
RE: 4130 steel protection
In a few cases, I've seen these types of rods have a small hole drilled into them and then a small amount of preservative injected into the tube. The hole is then closed of with either a rosette weld or some other type of plug.
RE: 4130 steel protection
We used some goop based on lanolin for some 15-5 struts' insides once.
RE: 4130 steel protection
Cosmolene?
RE: 4130 steel protection
They tried something better on the Fokker F27 which resulted in the following statement from the Airworthiness Directive:
"The interior of the tubes and end-fittings of the engine mount frames have been preserved with a film of preservation oil. Premature degradation of this synthetic preservation oil is considered to be the cause of the corrosion. "
see the following link for a discussion on using boiled linseed oil:
http://www.mechanicsupport.com/aircraft_tube.html
RE: 4130 steel protection
Linseed oil would work. Have also used Val Oil cut with Stoddard solvent. Normal handling during production would completely coat the inside of the tube. Verified by sawing several units in half.
RE: 4130 steel protection
B.E.