provide Hot-dip galvanizing HDG service galvanization galvanized Hot-dip HDG The hot-dip galvanizing is a way to improve the surface treatment ... . (2) Pickling H2SO4 15% can be used, thiourea 0.1%, from 40 to 60 ° C, or with HCl 20%, methenamine 3 ~ 5g ... 4.5-5.5. heating, heating should be uniform, and to prevent local overheating. provide Hot-dip galvanizing HDG service