G2MT is pleased to be among the many great presenters at this years ASM Houston Failure Analysis seminar. The meeting was held February 2, 2016, at the Kingwood Country Club, where we specifically discussed two topics that we have seen lead to many failures: (1) microstructure in specifications and (2) the importance of the oxide for corrosion protection.
Microstructure in Specifications: When steel is purchased for industrial uses, the requirements of the steel (e.g. ingredients, strength, corrosion resistance) are typically specified by ASTM or other similar groups. Many companies have additional requirements beyond the manufacturer’s specification based on their own needs and previous experiences. Recently, we see more and more companies including microstructure analysis as part of their specification. This makes great sense as the variety and quality of steel and other metals changes dramatically depending on how they are made. The chemistry and tensile properties may be acceptable but the ultimate performance is still sub-par in some cases. Microstructure analysis is the of the best ways to ensure your metal is really what you think it is.
The Importance of the Oxide: Oxides are the thin layer of metal mixed with oxygen that are the key to corrosion resistance and performance of titanium, aluminum, stainless steel, and other alloys. So long as the oxide is in place, these metals will corrode very slowly; but take the oxide away and run-away corrosion can occur. Unfortunately, many times materials are tested and used in a way that only evaluates the passive state (when the oxide is in tact) but neglects to evaluate what happens when the oxide is broken (the active state). In the real world, there are many different processes that can break the oxide and this leads to the case where materials corrode and/or fail very prematurely.