Just about every engineer; anywhere in the world; who is involved with manufacturing and producing will have come across ASTM standards. Many may not be aware that in 2001 it changed its name to ASTM International; nor that ASTM is one of the oldest of the world’s recognized standards institutions; having been founded in 1898 as the American Section of the International Association for Testing and Materials (the British did not found their standards institute until 1901 and the Germans 1917; even our own ANSI – American National Standards Institute – didn’t start until 1918).
The world talks about the need for fully international standardization (including doing away with inches and °F) and following the ideals of the International Organization for Standardization (known as ISO); but, especially in engineering aspects for sectors such as oil and gas; petrochemicals and aerospace; the American standards have become the international norm. Standards set by ASTM, ANSI, along with API (American Petroleum Institute) following guidelines from ASME (American Society of Mechanical Engineers) are in everyday use everywhere.
Steel is a basic iron alloy; but, the demands of today’s engineering; where ever higher, or lower extremes of temperature are being encountered and components must also resist ever higher pressures, loads and stresses; have led to the development of what are known as superalloys. These are often the result of one specialist metal producer’s research but the materials rarely stay a private, patent protected preserve and, once the material becomes more widely available, a standard will be drawn up that states the basic chemical composition of the alloy, describes important production steps; determines tests that the producer must carry out and also discusses ways in which the alloy can be used and any additional steps that may be required.
Rockwell Standard ASTM B637 Alloy was formulated by a specialist ASTM sub-committee (B02.07) that deals with refined nickel; cobalt and their alloys. The full title is “ASTM B637 – 12e1” which deals with the specification covering precipitation hardened nickel alloy in bar form or forging stock for high temperature use.
Nickel 718 (aka Inconel 718)
ASTM B637 alloy is available in commercial form under different maker’s names and is sometimes referred to as Nickel 718; although more popularly known as Inconel 718 (the Inconel trademark now belongs to Special Metals Corporation who acquired it from Inco Alloys.