acid pickling and activating treatment is foundation to form complete and compact phosphating film on surface of GCrl5 steel coil. With controlling the ratio of phosphating liquid total acidity and free acidity- 5. 5 ~ 7. 5
phosphating temperature 70 ~80 °C . and using sodium stearic acid for soaping at 90 °C for 20 min
it is available to get the quality phosphating film and soaping film
and it is propitious to cold-work of bearing steel coil.