Passivation of materials is needed from time to time due to potential contamination of processes, aesthetic  appearance or function within a system. It is used to remove surface contaminants from forming, machining, shot peening and heat treating. This surface preparation generally does not change the tolerances, and should not etch or pit the surface.

For aerospace applications using NITRONC 60, AMS 2700 Method 1 or 2 can be employed to clean the surfaces. Usually just a small amount of nitric will clean it up nicely in Method 1, such as a Type 1 or 6.    We have found the citric acid in Method 2 to be ineffective to sufficiently brighten the appearance, though it may be employed as a process. 

Typically, materials being removed are due to a free iron concern. Free iron from tool steels, racks for storage and rollers can leave trace amounts during transfer. The free iron then will oxidize and give the appearance that the stainless is rusting, even when it is only the surface. 

A Niton XRF metal analyzer used in metal distribution

An article in 2012 about a Naval supplier misidentifying materials prompted the discussion internally about what procedures and services we could implement in order to remedy a situation like this. It offers peace of mind in knowing that the material you are buying is actually what you are buying. Without this high tech piece of equipment, you would have to depend on the reliability of your supplier and their entire supply chain to get it right every time. It is simple math that the more products that are handled, the greater chance for misidentification.

High Performance Alloys is a producer of forgings and bar products. Radial forged bars have been made in Tipton since 1994, and press forging was added in 2006.

NITRONIC 60  in H2S  has had three annealed heats (Rb95/98) tested for the NACE MR-01-75 standard, and it passed. Unfortunately, the committee wanted to see results up to Rc22 for annealed material (a larger barrage of testing) and it was never completed.

High Performance Alloys will be exhibiting at NACE 2013 in Orlando this week, March 18-21. Located in booth 419! Please feel free to stop by and say HI to David, Glenda, Rick and Cindy through the week. They have all kinds of goodies to hand out, and their smiling faces will just bring tons of joy to your day. Stop by and say you say the posting on the 'NET'.

A stainless is defined as 12% minimum Chromium, which can encompass many stainless grades. There are sub categories of this Austenitic type stainless though. Depending on the composition, some materials are more Austenitic than others; primarily due to their Nickel (Ni), Manganese (Mn), Carbon (C) and Nitrogen (N) contents. To consider this further, you need to understand the corollary to Austenite; Ferrite and Martensite are what many people are looking for when they require magnetism, or magnetic permeability. When you mix Austenite and Ferrite it is a Duplex (contains both, nearly equal amounts). A low Ferrite number generally indicates a lower magnetic permeability. Stainless that is high in Ni, Mn, C, or N or a combination thereof can be an indicator that it will have a lower Ferrite content. Some stainless steels with generous amount of these attain a negative ferrite calculation, using Schaefflers diagram you can predict these on a graph or us a Ferrite Number (FN) formula to arrive at the estimate.

We received some interesting feedback from our surveys this last year. I am happy to announce that the results are very positive. Here are the outcomes as tallied: Quotes 85% positive with 7% negative and Orders were 92% positive with 4% negative. There were some neutral survey points that neither help nor hurt. More order surveys were completed than Quotes surveys. Yes, ideally, we would love to be at 110% on both of these surveys - but overall our QA seems happy with the metrics. We had about as many neutral as negative with an overwhelming positive outlook on High Performance Alloys.