In view of the problem of bulge particle defect on the surface of hot-dip galvanized sheets, the causes were analyzed by investigating defect characteristics and surface cleanliness of cold-rolled steel sheets. The results show that the cause of bugle particle defect lies mainly in the residual iron on the surface of cold rolled steel sheets, which has not been cleaning off during degreasing and interfere the normal formation of coating. The bugle particle defect can be effectively prevented when the laser-textured work rollers of No.1 stand of HC tandem cold mills are replaced by smooth rollers, because the residual iron on the surface of cold rolled steel sheets can be reduced obviously.

As the worldwide demand for crude oil and gas increases and the oilfields age, the annual production of produced water is rising dramatically. Environmental restrictions on the disposal of this waste water have become more stringent in recent years with the result that disposal costs are also raising rapidly. This paper examines the various options for the treatment of this produced water prior to its disposal together with the possible consequences of getting it wrong, such as corrosion and scaling of process piping and equipment, together with fouling of the oilfield rock formation and disposal wells.