1、 FORD LABORATORY TEST METHOD AZ 001-02 Date Action Revisions 2000 08 30 Revised Editorial no technical change A. Cockman 2000 05 22 Revised Editorial no technical change A. Cockman 1992 07 07 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Technologies, Inc . DETERMINATION OF
2、 METAL CONTENT OF ACID PICKLING BATH Application This procedure determines the metal content of sulfuric acid pickling baths used in the phosphate coating process. An appreciable metal build - up indicates a need for replacement of the ba th. Apparatus Required Pipet - 1 mL Buret - 50 mL Erlenmeyer
3、flask - Pyrex - 50 mL Solutions Required Potassium Fluoride - 25 % Dissolve 25 g of potassium fluoride - KF 2H 2 O in distilled water and dilute to 100 mL. Standard Sodium Hydroxide - 0. 1 N Phenolphthalein Dissolve 0.2 g of phenolphthalein in 50 mL of ethyl alcohol and add 50 mL of distilled water.
4、 Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/ - 2 C and 50 +/ - 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TE
5、ST METHOD AZ 001-02 Page 2 of 3 Copyright 2000, Ford Global Technologies, Inc. Procedure Free Acid 1. Pipet 1.0 mL of the pickling bath into a 50 mL flask. 2. Add 10 mL of 25 % potassium f luoride and 10 drops of phenolphthalein. 3. Titrate promptly with NaOH (0.1 N) to a permanent pink color. mL of
6、 0.1 N NaOH = points of free acid Total Acid 1. Pipet 1.0 mL of the pickling bath into a 50 mL flask. 2. Add 25 mL of distilled water and 10 drops of phenolphthalein. 3. Titrate with 0.1 N NaOH to a permanent pink color. mL of 0.1 N NaOH - points of total acid Report the metal content of the picklin
7、g bath by means of the attached Nomograph, using the amount of free acid and total acid deter mined above. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD AZ 001-02 Page 3 of 3 Copyright 2000, Ford Global Technologies, Inc. DETERMINATION OF METAL CONTENT OF ACID PICKLING BATH
