Environment-friendly water-based treatment agent for improving phosphatability of high-strength steel

Abstract

The present invention belongs to the technical field of surface treatment for metal materials, and particularly relates to an environment-friendly water-based treatment agent for improving the phosphatability of high-strength steel. The water-based treatment agent is prepared by dissolving or dispersing a composition in an aqueous medium. The water-based treatment agent specifically consists of: A. a fluoride ion-containing compound; B. a compound selected from metal ion compounds containing Cu, Zn, Mn, Ni or Fe; C. a compound selected from organic acids; and D. a compound selected from surfactant. The water-based treatment agent can be diluted in water at a ratio of 1:0-20 for subsequent use. The treatment agent can enable the surface of a high-strength steel plate to have excellent phosphatability and is mainly applied to high-strength steel surface modification treatment.

1 . An environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel, wherein the water-based treatment agent is prepared by dissolving or dispersing a composition in an aqueous medium, wherein the water-based treatment agent specifically comprises:
 A. a compound selected from compounds containing fluoride ions;   B. a metal ion compound selected from compounds containing Cu, Zn, Mn, Ni, and Fe;   C. a compound selected from organic acids;   D. a compound selected from surfactants.   
     
     
         2 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein the compound containing fluoride ions is selected from one or more of ammonium fluorotitanate, ammonium fluorozirconate, potassium fluorotitanate, potassium fluorozirconate. 
     
     
         3 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein a molar concentration of the F element in the water-based treatment agent solution is 0.3-1.8 mol/L, 0.3-1.7 mol/L, or 0.6-1.1 mol/L. 
     
     
         4 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein
 the metal ion compound containing Cu is selected from sulfates, carbonates, and nitrates that contain copper ions;   the metal ion compound containing Zn is selected from sulfates, phosphates, formates, and acetates that contain Zn ions;   the metal ion compound containing Mn is selected from phosphates, carbonates, and nitrates that contain Mn ions;   the metal ion compound containing Ni is selected from sulfates, nitrates, and carbonates that contain Ni ions;   the metal ion compound containing Fe is selected from nitrates and oxalates that contain Fe ions.   
     
     
         5 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein a molar concentration of the metal ion compound in the water-based treatment agent solution is 0.05-0.6 mol/L, 0.07-0.6 mol/L, or 0.1-0.25 mol/L. 
     
     
         6 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein the organic acid compound is an organic acid compound with a complexing or chelating function, or is selected from one or more of citric acid, oxalic acid, tannic acid, lactic acid, tartaric acid, and salicylic acid. 
     
     
         7 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein a molar concentration of the organic acid compound in the water-based treatment agent solution is 0.03-0.4 mol/L, or 0.05-0.2 mol/L. 
     
     
         8 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein the compound selected from surfactants is selected from one or more of sodium dodecyl sulfate, sodium dodecyl sulfonate, calcium dodecyl sulfonate, octadecylamine and triethanolamine. 
     
     
         9 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein a molar concentration of the surfactant in the water-based treatment agent solution is 0.002-0.015 mol/L, or 0.003-0.01 mol/L. 
     
     
         10 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 1 , wherein the water-based treatment agent further comprises 0-20 parts by weight of water. 
     
     
         11 . (canceled) 
     
     
         12 . A method for improving phosphatability of high-strength steel, wherein the method comprises: treating the high-strength steel with the environmentally friendly water-based treatment agent according to  claim 1  by immersion, spraying or roller coating. 
     
     
         13 . The method according to  claim 12 , wherein the method further comprises: treating the high-strength steel with a degreasing agent to remove dirt and oil adhering to its surface, then washing it with pure water to remove alkaline matter remaining on the surface, and then using the environmentally friendly water-based treatment agent to perform surface treatment on the high-strength steel after blow drying. 
     
     
         14 . A high-strength steel or a phosphated steel sheet obtained by phosphating the high-strength steel, wherein the high-strength steel has a nano-scale surface modification layer on the surface, wherein the nano-scale surface modification layer is formed from the environmentally friendly water-based treatment agent according to  claim 1  after drying. 
     
     
         15 . A method for phosphating high-strength steel, comprising: treating the surface of the high-strength steel using the method according to  claim 12 , and subjecting the high-strength steel obtained by treating the surface to degreasing, water washing, surface conditioning, phosphating, water washing and drying in sequence, so that the high-strength steel is phosphated. 
     
     
         16 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 4 , wherein a molar concentration of the metal ion compound in the water-based treatment agent solution is 0.05-0.6 mol/L, 0.07-0.6 mol/L, or 0.1-0.25 mol/L. 
     
     
         17 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 6 , wherein a molar concentration of the organic acid compound in the water-based treatment agent solution is 0.03-0.4 mol/L or 0.05-0.2 mol/L. 
     
     
         18 . The environmentally friendly water-based treatment agent for improving phosphatability of high-strength steel according to  claim 8 , wherein a molar concentration of the surfactant in the water-based treatment agent solution is 0.002-0.015 mol/L or 0.003-0.01 mol/L. 
     
     
         19 . The method for improving phosphatability of high-strength steel according to  claim 12 , wherein the high-strength steel is pickled high-strength steel or cold-rolled high-strength steel. 
     
     
         20 . The high-strength steel or a phosphated steel sheet obtained by phosphating the high-strength steel according to  claim 14 , wherein the phosphated steel sheet has a phosphating crystal coverage rate of ≥80%; a phosphating crystal size of ≤6 μm; and a phosphating film weight of ≥2 g/m 2 . 
     
     
         21 . The high-strength steel or a phosphated steel sheet obtained by phosphating the high-strength steel according to  claim 20 , wherein the phosphated steel sheet has a phosphating crystal coverage rate of 100%.