Oh, how times change!
Our customer technical support experts sometimes must go through some pretty old documentation to find what they are looking for. But these old documents also reveal how much has changed and what has been discovered. Our expert Geert-Jan Pluijms noticed below:
The “A” in AK Steel International stands for our original parent company ARMCO®, the American Rolling Mill Company, which itself was founded in 1899. ARMCO® is the original developer/inventor of 17-4 PH, which made its commercial debut in December of 1948.
So you can imagine that I sometimes come across some very old documentation. Case in point? A partial scan of a 1959 “Fabrication Data Bulletin” on the ARMCO® family of precipitation hardening stainless steels.
Note that ARMCO® 15-5 PH and ARMCO® PH 13-8 Mo are not mentioned. Those two grades had not been developed yet at that point.
While fascinating to read, the document does show its age however…
Many of the instructions and guidelines are as valid now as they were over 6 decades ago, at least one is better not followed today.
Above mentioned cooling “fairly rapidly until black” is still good practice as this avoids formation of detrimental chromium carbide precipitates. Covering “with light gage metal cover (nothing galvanized)” is also good advice to allow undisturbed cooling to room temperature.
But below instruction?
Using “very thin asbestos sheeting”?
While asbestos remains an excellent and cheap insulating material, it should never be used given its carcinogenic nature.
Oh, how times change.
Customer Technical Support Manager
The author is part of our team of metallurgical experts. These experts are industry veterans and can help customers find the right use for our products for their application. Geert-Jan has an MSc in Materials Science & Engineering and more than 15 years of experience in the field of metallurgy. In these years he has executed various tasks on a multitude of metal types and shapes. You can reach him via our contact form.
AK Steel International markets specialist steel products such as ARMCO® Pure Iron, stainless steel, metal products and composite auxiliary materials for the aerospace, automotive and industrial sectors.