Zinc-Based Coating Production Capabilities for Steel Sheet: Current Technical Topics and Scientific Needs

摘要

Galvanizing line capabilities have evolved significantly in several directions since the 1980s. This has been primarily in response to demands by automotive customers to produce lighter vehicles by using thinner steels with improved mechanical properties of higher strength combined with formability and excellent coating uniformity. Other applications, such as those in construction and appliance industries, now require improved corrosion resistance, formability and painted appearance. These demands have resulted in enhancements to every section of the continuous hot-dip galvanizing line (CGL), and the average line capacity has been increased. Currently, several technical issues are at the forefront in galvanizing line process and product development, including strip heat treatment technology; control of coating appearance and thickness uniformity, improvements in pot hardware and post treatments such as organic coatings. The current state of knowledge relating to each of these issues will be discussed from a North American perspective along with areas in which our knowledge is still incomplete.