SURFACE TREATED STEEL MATERIAL, A METHOD FOR ITS MANUFACTURE, AND A CHEMICAL CONVERSION TREATMENT LIQUID.

摘要

A CHEMICAL CONVERSION TREATMENT LIQUID (1) CAN STABLY FORM A PHOSPHATE-TYPE CHEMICAL CONVERSION FILM ON A STEEL MATERIAL FOR A JOINT FOR AN OIL WELL PIPE CONTAINING 0.5-13R. USING A CHEMICAL CONVERSION TREATMENT LIQUID (1) TO WHICH A PRESCRIBED AMOUNT OF POTASSIUM IS ADDED, A CHEMICAL CONVERSION FILM CONTAINING A PRESCRIBED AMOUNT OF POTASSIUM COMPOUNDS AND HAVING A PRESCRIBED THICKNESS CAN BE FORMED ON THE THREADED SURFACE OF A JOINT FOR AN OIL WELL PIPE. (FIGURE 1)