Euro Steels & specs 2

[cmarinelli]

Hello All,

I am Reverse Engineering two aircraft fasteners that have me thrown for a loop because the materials are not US-type HSLA steels.

The first is a 30NCD16 steel that is 180-200KSI in the H & T condition. The only specs I can find on this material are prEN2478 and prEN2137. Is anyone familiar with any other spec for this material, or any bolt fabrication specification using this material akin to AS7466 for Inco718?

The second is a through-hardening nitriding steel that chemically matches BS970 897M39. Is anyone knowledgeable about this alloy? Again, any bolt fabrication specs for this material? It looks like there was a major revision of BS970 recently - does anyone know how the spec was broken up (i.e. nitriding steels are in a different spec)?

Last, does anyone know any material consultants that would be very familiar with European HSLA steels and bolt fabrication specs?

Thanks in advance!

Chris Marinelli
Dynatech Aerospace

 

[TVP]

First, 30NCD16 is a french designation for a Ni-Cr-Mo steel alloy. It is produced by a number of companies in Europe such as Ugitech (Arcelor), Ascometal (now part of Lucchini), Corus (formerly British Steel), and Edelstahlwerke S[&uuml;]dwestfalen (formerly Krupp Edelstahlprofile). The AECMA standard prEN 2137 is for steel bars of this grade with tensile strength = 1100-1250 MPa and diameter < 100 mm. prEN 2478 covers steel bars with ts = 1250-1400 and diameter < 40 mm. I am guessing that that this is a non-standard bolt since you did not provide a product standard. The very high levels of alloying elements (1.2% Cr, 0.5% Mo, 4% Ni) mean that this grade can be through hardened even in very large sizes, but it usually requires hot heading in order to be formed.

The second grade, 897M39 according to BS 970 (formerly EN 40C) is also known as 39CrMoV13 9 (1.8523) according to BS EN 10085 NITRIDING STEEL - TECHNICAL DELIVERY CONDITIONS. It is used sometimes without nitriding for high temperature applications requiring good creep resistance. You can see how BS 970 has been parsed in the latest revisions by visiting BSI or Global Engineering:

http://global.ihs.com/search_res.cf...304B5B2D3C240A&country_code=US&lang_code=ENGL

If you would like more information about specifications/standards, materials, etc., just ask.

 

[cmarinelli]

TVP,

I must thank you for your detailed response. I actually contacted some of the mills you listed, and am awaiting information.

Thanks Again,
Chris Marinelli

 

[yates]

30NCD16 is a common material extensively used in aerospace bolts in France (30NCD16 being an AFNOR designation for 30NiCrMo16) European aerospace fastener standards (EN) allow substitutions of 8740, 4340, or BS.S.100 for fastener applications. In fasteners, material is normally used in 1100 MPa (160 ksi) min. state. Cold heading can be carried out for small diameters, whereas large diameter bolts have to be hot-headed. Aubert & Duval is another major source, on top of those mentioned by TVP.
Standard procurement specifications for 30NCD16 bolts are AIR9173 (M-thread, French ), ISO 7689(MJ-thread, international).
Would be pleased to help you out. daviddotyatesATalcoadotcom