Quick evaluation method of old-rolling plate phosphating property

Abstract

The invention discloses a method for quickly evaluating the phosphability of cold-rolled sheets. The steps are as follows: Step 1. Prepare a sodium tetraborate solution, and then adjust the pH value of the solution with hydrochloric acid at a concentration of 1:1, and the adjusted sodium tetraborate solution The solute concentration is 0.05 mol / liter, and the pH value of the solution at 25°C is between 5.5 and 6.9; step 2, place the cold-rolled sheet to be tested in the above-mentioned sodium tetraborate solution; step 3, use a potentiostat to record the cold The dynamic change process of the potential value of the rolling plate after entering the above solution, when an obvious inflection point appears, the test is terminated, and the potential-time record chart is obtained on the potentiostat; Steps 4 and 5, according to the abscissa of the inflection point on the potential-time record chart Value, that is, the time value of the inflection point, to judge the phosphating sensitivity of the cold-rolled sheet, and analyze and predict the phosphating film quality of the cold-rolled sheet after phosphating. The invention can quickly and accurately evaluate the phosphating characteristics of the cold-rolled sheet, predict the coating quality of the cold-rolled sheet, and has wide applicability.

Description

technical field [0001] The invention relates to a method for predicting the phosphatability of a cold-rolled sheet. Background technique [0002] Cold-rolled sheet is a heterogeneous material. The chemical composition of the material, the diversity of rolling and annealing processes lead to huge differences in the composition and characteristics of the surface of the cold-rolled sheet, making the cold-rolled sheet before coating, including degreasing, rinsing, Surface conditioning, phosphating, rinsing and other processes will have different behaviors, resulting in differences in the phosphating properties of cold-rolled sheets, which will further lead to the appearance quality and corrosion resistance of cold-rolled sheets after coating. different. In order to prevent poor phosphating quality of the cold-rolled sheet, it is necessary to evaluate the phosphating ability of the cold-rolled sheet before formal use. [0003] At present, the main application industries at home...

AI Technical Summary

Problems solved by technology

[0005] 1. Time-consuming: It takes 1 to 2 hours to complete the phosphating sample preparation at the production site, and another 2 to 3 hours for the film weight and microscopic morphology analysis of the small sample, a total of 3 to 5 hours, and this does not include the transportation of the sample time; while it takes 2-3 hours for phosphating solution preparation time to complete phosphating sample preparation in the laboratory, if the laboratory is far away from the production site, the time required may be as long as several weeks

[0006] 2. High cost: The entire production line must be run for sample preparation on the phosphating site. The cost includes manpower, equipment operation, chemicals, energy media, etc. Generally speaking, at least RMB 50,000 is required

[0007] 3. The applicability is not wide: For cold-rolled plate suppliers, it is necessary to obtain the phosphating chemicals of each specific user, including degreasing agents, surface conditioners and phosphating solutions, etc. At the same time, it is necessary to understand the phosphating chemicals It is difficult to evaluate the process parameters of the product before it can be phosphatized; and even if all the information is obtained, the results are only applicable to this user and are not universal

[0009] 1. The evaluation results are only applicable to specific users who use the phosphating solution and are not universal;

[0010] 2. The prediction result is incomplete, only the quality of the phosphating film can be predicted, but the sensitivity of the cold-rolled sheet to phosphating cannot be predicted

[0012] 1. It can only evaluate the difference in surface properties before and after phosphating of cold-rolled sheets, but cannot distinguish the difference between the phosphating quality of different cold-rolled sheets;

[0013] 2. The cold-rolled sheet must be placed in the real phosphating solution to obtain the phosphating film, otherwise the prediction cannot be realized

Images