【正文】 e phosphatization, it should be dried and sprayed immediately.②Dehydrogenation (200? or so), 2h.③Regulate phosphatization liquid parameters, be noted that free acid solubility should not be too high.④Change to fresh water and clean the spray nozzle, keep hydraulic pressure.⑤Stop using and substitute with tape water. Check PH value and 67 is required.⑥Take fresh sample powder and test its quality according to standard solidification condition.2Hole Shrinkage①Water or oil gets in during production of powder, evenly distributed in form of tiny round holes or large needle holes.②Other powder gets in during spraying and causes hole shrinkage since they aren39。t consistent.③Spray system (including workpiece) polluted by outer impurity matters, especially silicon remover and waterproofing reagent in the workshop.④Casting surface has large and deep holes.⑤Round and large holes appear on the coating layer, called as fish eyes.⑥Compressed air has high content of oil.①Contact producer to change the powder. ②Complete change and cleaning of spray room. Better if working out cleaning and checking procedure.③Check spray scene carefully and dispose of impurity matters. Make regulations to prevent intrusion of these matters.④Complete sand spray. Casting should be preheated at temperature and time subject to materials and thickness.⑤Pollution of drying and solidifying furnace channel should be cleared. Check lifter and rubber belt pollute the powder or not.⑥Check filter of air pressor, add oilwater separator and discharge regularly in every shift.3Partial or most area shedding of the coating area①Uncleared rust on surface of the base material.②Unclean washing, especially after phosphatization.③Unplete deoiling of surface of base material.④Lubricant on the chain drops to the work piece.⑤Bubbling of galvanized board and shedding of coating layer.①Through rust removal.②Check flowing quantity, water quality and nozzle. Check washing flow rate and pressure.③Use chemical oil removal (suitable for plant oil and not suitable for mineral oil) with alkali. And wash forcefully ten (pay attention to water quality)④Check lubricant index. If necessary, replace with lubricant of higher withstanding temperature or place receiver under dripping point.⑤Refer to attachment I.4Yellowing of the coating layer①Set temperature of the furnace channel or oven is relatively high.②Gas gets into the oven or furnace channel directly.③Too long stay in the furnace channel or oven, or conveyance chain stops running.④Powder quality.⑤Repeated baking of workpiece for more than 2 times.⑥Serious decoloring of the dope.①Get to know normal solidification condition and adjust.②Heating thermal exchanger.③Get to know baking condition. Be noted that whether conveyance chain running normal or not closely. If stop producing, end all workpiece baking and discharge the materials.④Powder supplier offers sample boards under different baking condition for reference in course of spraying.⑤Try to finish baking one time. Workpieces needing second baking should be treated centrally and determine repeated baking condition first.⑥Check baking temperature too high or not(. 230? or even higher. Check withstanding capability of the powder.5Luster unstability①Lower luster②Higher luster③Fluctuate luster④Sudden dropping of luster①Check baking temperature and time proper or not and consult powder manufacturer about baking condition. And also water content and humidity of the spray room in addition.②Exam baking temperature and time according to ①. Check luster and workpiece thickness and baking condition.③See it39。s connected with gas furnace directly or not. Check whether there is impure powder and change of spray humidity. Check furnace tunnel or stove temperature stable or not.④Check the temperature uncontrolled or not. Check air pression system and oil/water separation normal or not. Check whether there is impure powder. 6Partial unevenness and leveling unstability.①Caused by uneven thickness.②Large change of powder grainness.③High voltage breakthrough.④Internal pipe abrasion of Wenqiu and uneven powder spray.⑤Improper powder spray pipe and equipment.⑥Jamming of conveyance chain and uneven speed.⑦Holed board inside the sulfuration damaged or jammed partially.①Strengthen film thickness control. Check powder spray system (powder supply, reclaiming and spray gun voltage etc.) normal or not.②Notice powder factory to inspect.③Lower powder spray voltage. But insure normal film thickness and increase powder spray pressure or enlarge distance between spray gun and the workpiece.④Check and replace.⑤Contact equipment supplier, check and replace.⑥Repair hanging chain and make it run at even speed.⑦Check flowing condition and repair holed board.7Sand material ①Appear evenly and densely.②It39。s round and protuberant.③A few sand grains, of different sizes.④There is impurity on surface of the workpiece, sometimes looking radiationtype or slender⑤A few black grains.①Measure film thickness to see it conforms to technique requirement or not.②Check powder quality to see whether there are gel particles and impurity on surface of the workpiece after phosphatization.③Mainly caused by unclean environment. Keep tidy any time.④Check powder quality, the operator should try not to wear trousers or gloves falling tiny fibrin.⑤Impurity of the furnace tunnel (such as gel matter) gets on the workpiece, please clear periodically. 8No spray or insufficient spray①Inferior powder spray material. The powder is easy to attach on its internal wall.②Insufficient pressure or air quantity.③The spray pipe is heated therefore powder sinters inside the pipe.④The spray pipe is bent and twisted.⑤The powder sinters and can not flow normally.①Replace high quality spray pipe.②Check air source and pressure and regulate.③Install airconditioner. Check grainness of the powder. If too rough please notice the powder factory to modify.④Check powder spray pipe, and regulate position of the regulation pipe.⑤Screen first. If it doesn39。t work, change the powder.