The workpiece surface layer adhesion is not good.
1. The pretreatment water caused by incomplete workpieces residual degreasing agent, or chromium slag washing trough by alkali liquor pollution caused by the poor adhesion.Solution is to strengthen water, adjust good degreasing process parameters as well as prevent degreasing liquid into the water tank after phosphating.
2. The phosphating film yellow, hair flower or partial phosphating film caused by poor adhesion.Solution is to adjust phosphating bath concentration and the proportion, improve phosphating temperature.
3. The workpiece edge water and cause the poor adhesion of drying is not clear.
4. The solution is to improve the drying temperature curing temperature is not caused by large area coating adhesion is poor.The solution is to improve the curing temperature.Because of the artifacts in the oven curing temperature and time is not enough.General workpiece powder curing temperature is 180 degrees for 20 minutes.But we often encountered in the actual production of the workpiece is thick, when the thickness is greater than 3 mm, the workpiece temperature in the furnace should be appropriate to 200 degrees, workpiece heat preservation time should be at least 40 minutes.The artifacts have problems solution, heat curing.