IN MOST INSTANCES, corrosion test methods for plain carbon steels, high-strength low-alloy steels, and alloy steels do not differ greatly. Therefore, these steels are grouped together for the purposes of this chapter. (Alloy steels here refers to heat treatable constructional and automotive steels, and does not include the stainless steels or other high alloys.) There are some differences in the corrosion test methods used for different mill products of this group of steels, and these will be discussed. The steels covered in this chapter are defined below.