Study on Properties of Anti - Galling Phosphating Films for Threads of Oil Drilling Tools

In order to confirm the performance of different phosphating films and their influences on the anti-galling effect of the threads of petroleum drilling tools,the comprehensive anti-galling performance including appearance,film thickness,film weight,surface roughness,adhesion,corrosion resistance,crystal morphology and size,makeup and breakout test results of the films obtained through normal temperature zinc-calcium phosphating,low temperature zinc phosphating,mid temperature zinc-manganese phosphating and mid temperature zinc-calcium phosphating were studied.Results showed that the “sand blasting &immersed phosphating”process could ensure the performance of anti-galling phosphating film well.The phosphating films with high film thickness and weight,fine phosphating crystals and good adhesion had better corrosion resistance and antifriction-lubrication effect.The films obtained through low temperature zinc phosphating and mid temperature zinc-manganese phosphating could both meet the anti-galling application