Virtually all engineering materials will corrode or decay over time when exposed to their environment. The rate of decay depends on the material and conditions. Like the human body, materials require protection from extreme temperatures, pressures, and harmful gases through coatings, inhibitors, alloys, maintenance and inspection. Corrosion causes the disintegration of materials into constituent atoms via chemical reactions with the surroundings like oxygen, and reduces material strength, lifetime and properties. Data on corrosion rates helps determine if a material is suitable for an application, with over 50 mils per year generally unsuitable. Common types of corrosion include uniform, galvanic, pitting, stress, erosion and microbial. Protections methods aim to control reactions or provide permanent barriers