What Does Green Death Mean?
Green death is a type of solution commonly used in the testing of corrosion resistance of metals. This solution is composed of the following:
- Sulfuric acid - 11.9%
- Hydrochloric acid - 1.3%
- Iron chloride - 1%
- Copper chloride - 1%
The green death solution acts as a synthetic environment where corrosion can take place. This test measures the level of resistance a certain metal has when exposed to environments similar to the conditions present within the solution.
Corrosionpedia Explains Green Death
The use of green death solution makes it possible to achieve an oxidizing chloride solution. A highly aggressive oxidizing chloride atmosphere is required to distinguish the alloying effects on local corrosion resistance of some new alloy generations such as in the case of nickel.
Moreover, this solution is used to test the relative resistance of nickel alloys and stainless steel. Typically, resistance from crevice corrosion involving several crevice specimens is tested under green death for a maximum period of 24 hours under a boiling temperature of 217°F (103°C).
Localized corrosion is less predictable than general corrosion and is more damaging, which causes serious limitations on the performance of certain materials. With this, the pitting resistance equivalent number (PREN) can be computed utilizing the chemical composition of the alloy in order to measure the pitting resistance of different alloys. This is possible through corrosion testing that evaluates crevice and critical pitting corrosion in various test solutions. One of these is the green death solution.