SCC of 17-4PH H900 Drive Rod 1

[SSMroz]

I am currently working on a 17-4PH H900 drive rod that failed by SCC. I am having troubles nailing down the possiable causes of SCC in 17-4PH. We have found traces of cholrine and sulfur in the corrosion products. The rod would have operated at temperatures up to 300-F. Are cholrin or sulfur known to cause SCC at these temperatures? Also, pits were observed along the surface that the SCC intiated.

Thanks for any help anyone can offer.

 

[EdStainless]

YES.
If you have pits then you have active corrosion. Once that happens CSCC will be a high prob.
One problem with PH grades in there highest strength condition is that the CSCC easily.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[TVP]

As EdStainless mentioned 17-4PH in the H900 condition is susceptible to SCC. The following references may be useful to you in describing susceptibility to SCC, etc.:

NASA MSFC-SPEC-522

http://www-glast.slac.stanford.edu/...nces/NASA/stress-corr-crck-msfc-spec-522b.pdf

DEF STAN 00-970 PART 1/3 Section 4 (Leaflet 7)

http://www.dstan.mod.uk/data/00/970/01040307.pdf

 

[btrueblood]

http://www.aksteel.com/pdf/markets_products/stainless/precipitation/17-4_PH_Data_Bulletin.pdf

Includes a discussion of SCC.

 

[SSMroz]

Thank-you all for the resources. They were very helpfull in this situation.

 

[Kenneth]

While MSFC-SPEC-522 remains a valuable reference, it has been superseded by NASA-STD-3029

http://psrp-pub.jsc.nasa.gov/docs/3029.pdf

(which isn't much changed from MSFC-SPEC-522)...

 

[Kenneth]

The docuement located at the NASA link I supplied above is already out of date. MSFC-STD-3029 (not "MSFC-SPEC-3029" as I typed above), is currently at the "A" revision...