Acidic water-based treating agent for removing corrosion on surface of black metal and forming antirust passivation layer

Abstract

The invention discloses an acid-based treating agent for removing corrosion on the surface of black metal and forming an anti-rust passivation layer at the same time as well as preparation and application of the acid-based treating agent. The acid-based treating agent comprises the following components in percentage by mass: 0.01-50wt% of polymaleic acid and derivatives thereof, zinc ions with the molar concentration of 0-2mol / L and phosphate ions with the molar concentration of 0-2mol / L; the pH value range of the acidic water-based treating agent solution is 0.5-5.0; when the acidic water-based treating agent is coated on the surface of the black metal, the acidic water-based treating agent can effectively help the black metal to remove corrosion on the surface and form a new high-performance corrosion-resistant passivation coating resistant to corrosion of acid, alkali, salt, seawater and the like, and the corrosion resistance of a metal substrate can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal surface treatment, and specifically relates to an acidic water-based treatment agent for removing corrosion on the surface of ferrous metal and forming an anti-rust passivation layer and an application thereof. Technical Background

[0002] Metal corrosion poses significant hazards to various industries and applications, affecting infrastructure, safety and economic viability. According to the World Corrosion Organization (WCO), the global cost of corrosion is estimated to exceed $2.5 trillion per year. The corrosion of metals, especially as structural materials such as mild steel, can cause serious damage, including collapse and environmental disasters. For example: the collapse of the Morandi Bridge in Genoa, Italy in 2018 killed 43 people. Between 2014 and 2018, corrosion was a contributing factor in approximately 15% of offshore oil and gas accidents in the Gulf of Mexico. These accidents all illustrate the huge impact of corrosion on human production and life, highlighting the need to take strong corrosion prevention measures.

[0003] Based on the specific impact of metal corrosion on human production and life, various anti-corrosion measures have been developed, including coatings, sacrificial anodes, etc. Among them, anti-corrosion coating technology has attracted widespread attention due to its simple construction method and low price. These anti-corrosion coatings slow down the corrosion rate of metals by isolating them from oxygen and water. However, the difference in thermal expansion coefficients between the above coatings and metal materials causes cracking, which destroys their anti-corrosion effect. Summary of the invention

[0004] In order to avoid the cracking and peeling caused by the different thermal expansion coefficients and poor adhesion between the metal substrate and the anti-corrosion coating, which may affect the anti-corrosion performance of the coating, the present invention proposes a new treatment agent that can generate a dense anti-corrosion coating in situ on the surface of ferrous metals. The acidic water-based treatment agent can also be used to generate a dense anti-corrosion coating in situ again on the surface of ferrous metals that have already formed rust after the rust layer is removed by acid, thereby improving the corrosion resistance of the metal substrate.

[0005] Specifically:

[0006] The first aspect of the present invention is to provide an acidic water-based treatment agent for removing corrosion on the surface of ferrous metals and simultaneously forming an anti-rust passivation layer, the main components of which are polymaleic acid and its derivatives, zinc ions and phosphate ions.

[0007] The polymaleic acid and its derivatives used in the present invention include: polymaleic acid, styrene maleic acid copolymer, acrylic acid maleic acid copolymer, polypropylene maleic acid copolymer, polyisobutylene maleic acid copolymer, methyl vinyl ether maleic acid, polyisoprene maleic acid copolymer, etc., with a molecular weight of 400-100000, and a solid content of 0.01-50wt% in the acidic water-based treatment agent. Preferably, the molecular weight of the polymaleic acid and its derivatives is 400-2000, and the solid content is 1-20wt%.

[0008] The zinc salt used in the preparation of the acidic water-based treatment agent of the present invention includes one or more of zinc phosphate, zinc sulfate, zinc phosphate, zinc acetate, zinc lactate, zinc nicotinate, zinc citrate, and zinc gluconate, and the molar concentration of the zinc ion is 0-2 mol / L. Preferably, the molar concentration of the zinc ion is 0.01-1 mol / L.

[0009] The phosphate used in the preparation of the acidic water-based treatment agent of the present invention includes one or more of zinc phosphate, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, aminotrimethylene phosphate, ethylenediaminetetramethylene phosphate or hydroxyethylene diphosphate, and the molar concentration of the phosphate ion is 0-2 mol / L. Preferably, the molar concentration of the phosphate ion is 0.01-1 mol / L.

[0010] The pH value of the acidic water-based treatment agent solution prepared in the present invention is 0.5-5.0. Preferably, the pH value of the acidic water-based treatment agent is 1.0-3.0.

[0011] The pH of the acidic water treatment agent in the present invention is adjusted by an acidic solution, and the acidic solution includes at least one of sulfuric acid, nitric acid, phosphoric acid, acetic acid, citric acid, maleic acid, fumaric acid, formic acid, glutamic acid or 2-propionic acid.

[0012] The acidic water-based treatment agent prepared by the present invention can be applied to the surface anti-corrosion treatment of ferrous metals, that is, the surface of which the main components are iron, manganese, chromium and alloys of the three metals.

[0013] The second aspect of the present invention is to provide a method for using the acidic water-based treatment agent described in the first aspect of the present invention, including a method of combining one or more methods of spraying, spin coating, immersion, electrospraying, and brushing to apply the acidic water-based treatment agent to the surface of a ferrous metal.

[0014] The third aspect of the present invention is to provide the application of the acidic water-based treatment agent described in the first or second aspect of the present invention, which is used for metals whose main components are iron, manganese, chromium and alloys of the three metals, while removing surface corrosion and forming a new high-performance anti-corrosion passivation coating that is resistant to corrosion by acids, alkalis, salts, seawater, etc.

[0015] The present invention can be used not only for newly prepared metals, but also for black-based metal materials whose surfaces have been partially modified but do not affect their use. The water-based treatment agent prepared by the present invention can remove the above corrosion and form a dense metal protective film on its surface.

[0016] The technical effects achieved by the present invention are:

[0017] 1. The acidic water-based treatment agent of the present invention has readily available raw materials and a simple preparation process;

[0018] 2. The acidic water-based treatment agent of the present invention can help ferrous metals remove surface corrosion while forming a new high-performance anti-corrosion passivation coating that is resistant to corrosion by acids, alkalis, salts, seawater, etc., which can effectively improve the corrosion resistance of metal substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic diagram of the preparation process of the acidic water-based treatment agent and the process of forming a passivation coating on the surface of the ferrous metal after the agent is applied to the ferrous metal;

[0020] like Figure 1 As shown, the acidic water-based treatment agent can be obtained by mixing polymaleic acid and its derivatives as the main components of the acidic water-based treatment agent, zinc ion salt, phosphate ion salt and acidic aqueous solution. The acidic water-based treatment agent is applied to the surface of a ferrous metal to obtain a ferrous metal containing a passivation coating. DETAILED DESCRIPTION

[0021] In order to further understand the present invention, the preferred technical scheme of the present invention is described in detail with specific examples below. The reagents and raw materials used in the following examples and test examples are all industrial pure commodities, and the equipment used are all commonly used equipment and devices in the field.

[0022] The technical solution of the present invention is described in detail below in conjunction with specific embodiments.

[0023] Example 1

[0024] Step 1, using polymaleic acid with a molecular weight of 400-800 to prepare a ferrous metal acidic water-based treatment agent with a polymaleic acid solid content of 5wt%, and adjusting the solution pH to 2.5 with a fumaric acid aqueous solution to obtain an acidic water-based treatment agent for removing ferrous metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0025] Step 2, soak the 20 carbon steel sample in the acidic water-based treatment agent obtained in step 1 overnight, and then rinse off the treatment agent remaining on the surface with clean water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0026] The corrosion rate of 20 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.16mm / y, and it can remain corrosion-free for 7 days in the acid mist test.

[0027] Example 2

[0028] Step 1, using polymaleic acid with a molecular weight of 400-800, zinc nitrate and sodium phosphate to prepare a black metal acidic water-based treatment agent with a solid content of polymaleic acid of 0.01wt%, a molar concentration of zinc ions of 0.3mol / L, and a molar concentration of phosphoric acid ions of 0.3mol / L, and adjusting the pH value of the solution to 2.0 with an aqueous maleic acid solution to obtain an acidic water-based treatment agent for removing corrosion on the surface of black metals and simultaneously forming an anti-rust passivation layer;

[0029] Step 2, soak the 20 carbon steel sample in the acidic water-based treatment agent obtained in step 1 overnight, and then rinse off the treatment agent remaining on the surface with clean water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0030] The corrosion rate of 20 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.16mm / y, and it can remain corrosion-free for 7 days in the acid mist test.

[0031] Example 3

[0032] Step 1, using a styrene-maleic acid copolymer with a molecular weight of 800-5000 and potassium phosphate to prepare an acidic water-based treatment agent with a solid content of 10wt% of the styrene-maleic acid copolymer and a molar concentration of phosphate ions of 2mol / L, and adjusting the pH value of the solution to 2.5 with 2-propionic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0033] Step 2: spray the acidic water-based treatment agent obtained in step 1 on the surface of the Q235 carbon steel sample to make it completely wetted by the water-based treatment agent. After it dries, spray it again. After repeating the spraying process 10 times, rinse off the treatment agent remaining on the surface with water to obtain Q235 carbon steel with a high-performance corrosion-resistant passivation layer on the surface; the Q235 steel can continue to be sprayed with paint on its surface to meet its decorative requirements.

[0034] The corrosion rate of Q235 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.11mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0035] Example 4

[0036] Step 1, using acrylic acid maleic acid copolymer with a molecular weight of 5000-8000 and zinc acetate to prepare an acidic water-based treatment agent with a solid content of acrylic acid maleic acid copolymer of 20wt% and a molar concentration of zinc ions of 2mol / L, and adjusting the pH value of the solution to 1.5 with formic acid and sulfuric acid solution, thereby obtaining an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0037] Step 2, drop the acidic water-based treatment agent solution obtained in the above step 1 on the surface of ZG25 cast steel, rotate at a speed of 800 rad / min, spin coating time of 1 min, wait for 6 hours, and after the spin-coated film is completely dried on its surface, rinse off the salt and polymer remaining on the surface with water to obtain cast steel with a corrosion-resistant passivation layer on the surface;

[0038] The corrosion rate of ZG25 cast steel treated with the acidic water-based treatment agent in seawater is reduced from 7.5 mm / y before treatment to 0.19 mm / y, and it can remain corrosion-free for 7 days in the acid mist test.

[0039] Example 5

[0040] Step 1, using a polypropylene maleic acid copolymer with a molecular weight of 8000-12000, zinc lactate, and sodium monohydrogen phosphate to prepare an acidic water-based treatment agent with a solid content of 50wt% of the polypropylene maleic acid copolymer, a molar concentration of zinc ions of 0.4mol / L, and a molar concentration of phosphate ions of 0.6mol / L, and adjusting the pH value of the solution to 1.0 with sulfuric acid and nitric acid solutions, thereby obtaining an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0041] Step 2: After the Q275 carbon steel is immersed in the acidic water-based treatment agent solution obtained in the above step 1 for 12 hours, the treatment agent remaining on the surface is washed off with clean water to obtain the Q275 carbon steel having a corrosion-resistant passivation layer on the surface;

[0042] The corrosion rate of Q275 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 6mm / y before treatment to 0.07mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0043] Example 6

[0044] Step 1, using a polyisobutylene maleic acid copolymer with a molecular weight of 12000-20000, zinc nicotinate, and phosphoric acid to prepare a polyisobutylene maleic acid copolymer with a solid content of 5wt%, a zinc ion molar concentration of 1mol / L, and using phosphoric acid to adjust the pH of the solution to 3.0, at which time the molar concentration of phosphate ions in the aqueous phase is 0.4mol / L of an acidic water-based treatment agent, and adjusting the solution pH to 3.0 to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0045] Step 2, spray the acidic water-based treatment agent obtained in the above step 1 on the surface of the Q255 carbon steel sample to make it completely wetted by the above water-based treatment agent, wait for it to dry, spray it again, repeat the spraying process 5 times, rinse off the treatment agent remaining on the surface with water, and you can get Q255 carbon steel with a high-performance corrosion-resistant passivation layer on the surface;

[0046] The corrosion rate of Q255 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 7.4 mm / y before treatment to 0.09 mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0047] Example 7

[0048] Step 1, using methyl vinyl ether maleic acid copolymer with a molecular weight of 20000-50000, zinc citrate and potassium phosphate to prepare an acidic water-based treatment agent with a solid content of 0.1wt% of methyl vinyl ether maleic acid copolymer, a molar concentration of zinc ions of 0.8mol / L, and a molar concentration of phosphate ions of 0.8mol / L, and adjusting the pH value of the solution to 0.5 with nitric acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0049] Step 2, soaking the Q195 carbon steel in the acidic water-based treatment agent solution obtained in the above step 1 overnight, and then washing away the treatment agent remaining on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0050] The use of this acidic aqueous treatment agent allows the in-situ generation of an anti-corrosion passivation layer on the surface of Q195 carbon steel. Compared with the untreated sample, the corrosion rate in seawater is reduced from the original 9.5 mm / y to 0.21 mm / y, and it can remain corrosion-free for 5 days in the acid mist test.

[0051] Example 8

[0052] Step 1, using polyisoprene maleic acid copolymer with a molecular weight of 50000-80000, zinc gluconate and sodium ethylenediaminetetramethylene phosphate to prepare an acidic water-based treatment agent with a solid content of 30wt% of polyisoprene maleic acid copolymer, a molar concentration of zinc ions of 0.01mol / L, and a molar concentration of phosphate ions of 1mol / L, and adjusting the solution pH to 2.0 with an aqueous solution of glutamic acid and citric acid, thereby obtaining an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0053] Step 2: Apply the acidic water-based treatment agent obtained in step 1 to the surface of the SK2 carbon steel by brushing, wait for it to dry, repeat the brushing for 5 times, and then rinse off the treatment agent remaining on the surface with water to obtain the SK2 carbon steel with a high-performance corrosion-resistant passivation layer on the surface;

[0054] The use of this acidic aqueous treatment agent allows the SK2 carbon steel surface to generate an in-situ anti-corrosion passivation layer. Compared with the untreated sample, the corrosion rate in seawater is reduced from the original 3mm / y to 0.03mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0055] Example 9

[0056] Step 1, using polymaleic acid with a molecular weight of 80000-100000 and zinc phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 50wt%, a zinc ion molar concentration of 1.2mol / L, and a phosphate ion molar concentration of 1.2mol / L, and adjusting the solution pH to 1.5 with nitric acid and fumaric acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and forming an anti-rust passivation layer at the same time;

[0057] Step 2, soak the component made of SK4 carbon steel in the acidic water-based treatment agent solution obtained in step 1 for 2 hours, then repair the unmodified corners of the edges and corners by spraying, and finally rinse off the treatment agent remaining on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0058] The use of this water-based treatment agent allows the SK2 carbon steel surface to generate an in-situ anti-corrosion passivation layer. Compared with the untreated sample, the corrosion rate in seawater is reduced from the original 3mm / y to 0.03mm / y. In the acid mist test, it can remain corrosion-free for 15 days.

[0059] Example 10

[0060] Step 1, using polymaleic acid with a molecular weight of 400-1200, zinc gluconate, zinc nicotinate and potassium phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 1wt%, a zinc ion molar concentration of 0.8mol / L, and a phosphate ion molar concentration of 0.5mol / L, and adjusting the solution pH to 1.5 with nitric acid and fumaric acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0061] Step 2, soak the SK5 carbon steel in the acidic water-based treatment agent solution obtained in step 1 for two days, and then rinse off the treatment agent remaining on the surface with water to obtain the SK5 carbon steel with a corrosion-resistant passivation layer on the surface;

[0062] The use of this acidic aqueous treatment agent allows the SK5 carbon steel surface to generate an in-situ anti-corrosion passivation layer. Compared with the untreated sample, the corrosion rate in seawater is reduced from the original 3mm / y to 0.06mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0063] Embodiment 11

[0064] Step 1, using polymaleic acid with a molecular weight of 1200-8000 and styrene maleic acid copolymer with a molecular weight of 400-1200, zinc nitrate, and phosphoric acid to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 10wt%, a styrene maleic acid copolymer solid content of 2wt%, a zinc ion molar concentration of 0.4mol / L, and a phosphate ion molar concentration of 2mol / L, and a solution pH value of 2.0, to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0065] Step 2: Spray the acidic water-based treatment agent obtained in step 1 onto the surface of SK7 carbon steel by electrospraying, wait for it to dry, and then spray it again. Repeat the above process 8 times, and then rinse off the treatment agent remaining on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0066] The use of this acidic aqueous treatment agent allows the SK7 carbon steel surface to generate an in-situ anti-corrosion passivation layer. Compared with the untreated sample, the corrosion rate in seawater is reduced from the original 2.5mm / y to 0.04mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0067] Example 12

[0068] Step 1, using polymaleic acid with a molecular weight of 400-800, zinc phosphate, zinc nitrate, zinc citrate and sodium ethylenediaminetetramethylene phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 15wt%, a zinc ion molar concentration of 0.1mol / L, and a phosphate ion molar concentration of 0.01mol / L, and adjusting the solution pH to 2.5 with citric acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0069] Step 2, drop the acidic water-based treatment agent obtained in step 1 on the surface of ASTM1070 carbon steel, spin-coat at a speed of 2000 rad / min for 2 minutes, so that the acidic water-based treatment agent forms a complete coating on the surface, then stand for 12 hours to dry, and rinse off the residual treatment agent on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0070] The use of this acidic aqueous treatment agent allows the sample with an in-situ anti-corrosion passivation layer to be formed on the surface of ASTM1070 carbon steel. The corrosion rate in seawater is reduced from 5 mm / y to 0.01 mm / y compared to the sample without treatment. The sample can remain corrosion-free for 20 days in an acid mist test.

[0071] Example 13

[0072] Step 1, using acrylic acid maleic acid copolymer with a molecular weight of 400-1200, zinc acetate, potassium phosphate, sodium dihydrogen phosphate and aminotrimethylene sodium phosphate to prepare an acidic water-based treatment agent with a solid content of 5wt% of polyacrylic acid maleic acid copolymer, a molar concentration of zinc ions of 0.5mol / L, and a molar concentration of phosphate ions of 0.8mol / L, and adjusting the pH value of the solution to 1.8 with fumaric acid and nitric acid aqueous solution to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0073] Step 2, soaking the ASTM1080 carbon steel in the acidic water-based treatment agent obtained in step 1 overnight, and then washing off the treatment agent remaining on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0074] The corrosion rate of ASTM1080 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 5mm / y before treatment to 0.02mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0075] Embodiment 14

[0076] Step 1, using polymaleic acid with a molecular weight of 400-800, polyisobutylene maleic acid copolymer with a molecular weight of 20000-50000 and zinc phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 3wt%, a polyisobutylene maleic acid copolymer solid content of 1wt%, and a zinc ion molar concentration of 0.5mol / L, and adjusting the solution pH to 2.0 to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0077] Step 2, soaking the ASTM1095 carbon steel in the acidic water-based treatment agent obtained in step 1 for 8 hours, and finally washing off the treatment agent remaining on the surface with water, thereby obtaining carbon steel having a corrosion-resistant passivation layer on the surface;

[0078] The corrosion rate of ASTM1095 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 4.5mm / y before treatment to 0.01mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0079] Embodiment 15

[0080] Step 1, using polymaleic acid with a molecular weight of 400-800 and zinc nitrate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 3wt% and a zinc ion molar concentration of 1.5mol / L, and adjusting the pH value of the water-based treatment liquid to 3.0 with citric acid and fumaric acid aqueous solution, thereby obtaining an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0081] Step 2, spraying the acidic water-based treatment agent obtained in step 1 on the gray cast iron for 5 times, and then washing off the treatment agent remaining on the surface with water to obtain the cast iron with a corrosion-resistant passivation layer on the surface;

[0082] The corrosion rate of cast iron treated with the acidic water-based treatment agent in seawater is reduced from 25 mm / y before treatment to 0.26 mm / y, and it can remain corrosion-free for 5 days in the acid mist test.

[0083] Example 16

[0084] Step 1, using polymaleic acid with a molecular weight of 800-1200, zinc gluconate and sodium phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 1wt%, a zinc ion molar concentration of 0.05mol / L, and a phosphate ion molar concentration of 0.5mol / L, and adjusting the solution pH to 2.0 with formic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0085] Step 2, soaking the Mn13 manganese steel in the acidic water-based treatment agent obtained in step 1 overnight, and then washing off the treatment agent remaining on the surface with water to obtain a manganese steel having a corrosion-resistant passivation layer on the surface;

[0086] The corrosion rate of Mn13 manganese steel treated with the acidic water-based treatment agent in seawater is reduced from 3mm / y before treatment to 0.01mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0087] Embodiment 17

[0088] Step 1, using a polyisoprene maleic acid copolymer with a molecular weight of 400-800 and sodium monohydrogen phosphate to prepare an acidic water-based treatment agent with a solid content of 3wt% and a molar concentration of phosphate ions of 0.6mol / L, and adjusting the pH value of the solution to 2.5 with acetic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and forming an anti-rust passivation layer at the same time;

[0089] Step 2, soaking the 410 chrome steel in the acidic water-based treatment agent obtained in step 1 overnight, and then washing off the treatment agent remaining on the surface with water, thereby obtaining chrome steel having a corrosion-resistant passivation layer on the surface;

[0090] The corrosion rate of 410 chrome steel treated with the acidic water-based treatment agent in seawater is reduced from 2 mm / y before treatment to 0.01 mm / y, and it can remain corrosion-free for 20 days in an acid mist test.

[0091] Embodiment 18

[0092] Step 1, using polymaleic acid with a molecular weight of 400-800 and zinc lactate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 10wt% and a zinc ion molar concentration of 0.1mol / L, and adjusting the solution pH to 2.0 with citric acid and formic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and forming an anti-rust passivation layer at the same time;

[0093] Step 2: Use a brush to apply the acidic water-based treatment agent obtained in step 1 to the surface of the 20 carbon steel that has pitting corrosion. After it dries, brush it with the acidic water-based treatment agent again. Repeat the above process 10 times to obtain carbon steel with a corrosion-resistant passivation layer on the surface.

[0094] The corrosion rate of 20 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.06mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0095] Embodiment 19

[0096] Step 1, using a polypropylene maleic acid copolymer with a molecular weight of 800-5000 and zinc sulfate to prepare an acidic water-based treatment agent with a solid content of 3wt% and a molar concentration of zinc ions of 0.3mol / L, and adjusting the pH value of the solution to 2.0 with acetic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and forming an anti-rust passivation layer at the same time;

[0097] Step 2: soak the acidic treatment agent obtained in step 1 with cotton cloth, and then use it to cover the Q195 carbon steel with surface corrosion overnight, and cover the outermost layer with a plastic film to slow down the evaporation rate of the treatment agent. Then, rinse off the treatment agent remaining on the surface with water, and the carbon steel with the surface corrosion removed and a corrosion-resistant passivation layer can be obtained;

[0098] The corrosion rate of Q195 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.09mm / y, and it can remain corrosion-free for 10 days in the acid mist test.

[0099] Embodiment 20

[0100] Step 1, using polymaleic acid with a molecular weight of 400-800 and zinc phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 0.5wt%, a zinc ion molar concentration of 0.3mol / L, and a phosphate ion molar concentration of 0.3mol / L, and adjusting the solution pH to 3.0 with citric acid and acetic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0101] Step 2, soaking the ASTM1095 carbon steel that has suffered corrosion fatigue in the above solution overnight, and then washing away the treatment agent remaining on the surface with water to obtain carbon steel with a corrosion-resistant passivation layer on the surface;

[0102] The corrosion rate of ASTM1095 carbon steel treated with the acidic water-based treatment agent in seawater is reduced from 4.5 mm / y before treatment to 0.02 mm / y, and it can remain corrosion-free for 15 days in the acid mist test.

[0103] Embodiment 21

[0104] Step 1, using polymaleic acid with a molecular weight of 400-800 and zinc phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 5wt%, a zinc ion molar concentration of 0.3mol / L, and a phosphate ion molar concentration of 0.3mol / L, and adjusting the solution pH to 2.0 with formic acid and acetic acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0105] Step 2: Spray the acidic water-based treatment agent obtained in step 1 onto the surface of the HRB400 steel bar where stress corrosion has occurred, wait for 30 minutes, and then spray again. Repeat the above process 20 times. Rinse off the treatment agent remaining on the surface with water to obtain carbon steel with a high-performance corrosion-resistant passivation layer on the surface;

[0106] The corrosion rate of HRB400 steel bars treated with the acidic water-based treatment agent in seawater is reduced from 6.8 mm / y before treatment to 0.06 mm / y, and can remain free of corrosion for 10 days in the acid mist test.

[0107] Embodiment 22

[0108] Step 1, using polymaleic acid with a molecular weight of 800-1200 and zinc phosphate to prepare an acidic water-based treatment agent with a polymaleic acid solid content of 3wt%, a zinc ion molar concentration of 1mol / L, and a phosphate ion molar concentration of 1mol / L, and adjusting the solution pH to 2.5 with maleic acid and sulfuric acid to obtain an acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer;

[0109] Step 2: Spray the acidic water-based treatment agent obtained in step 1 onto the 20 carbon steel ornament with surface corrosion, wait for 10 minutes, and then spray again. After repeating the above process 10 times, rinse off the residual treatment agent on the surface with water, and the corrosion on the 20 carbon steel ornament can be completely removed, and a new high-performance corrosion-resistant and rust-proof passivation layer can be re-formed, and a new coating can be sprayed on it to prepare a new ornament.

[0110] The corrosion rate of the 20 carbon steel ornaments treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.08mm / y, and can remain corrosion-free for 10 days in the acid mist test.

[0111] Embodiment 23

[0112] Step 1, using an acrylic acid-maleic acid copolymer with a molecular weight of 400-800, sodium phosphate, and zinc nitrate to prepare an acidic water-based treatment agent with a solid content of 5wt% of the acrylic acid-maleic acid copolymer, a molar concentration of zinc ions of 1mol / L, and a molar concentration of phosphate ions of 0.8mol / L, and adjusting the pH value of the solution to 1.8 with acrylic acid to obtain an acidic water-based treatment agent for removing corrosion on the surface of ferrous metals and simultaneously forming an anti-rust passivation layer;

[0113] Step 2: Soak the Q235 steel faucet that has been worn and corroded in an acidic water-based treatment agent for 48 hours, then rinse off the treatment agent remaining on the surface with water to obtain a Q235 steel faucet with surface modification removed and a corrosion-resistant passivation layer on the surface. Then re-spray it with new wear-resistant paint and reuse it.

[0114] The corrosion rate of Q235 steel faucets treated with the acidic water-based treatment agent in seawater is reduced from 8mm / y before treatment to 0.08mm / y, and can remain corrosion-free for 10 days in the acid mist test.

[0115] In summary, the acidic water-based treatment agent capable of in-situ generating a dense anti-corrosion coating on the surface of ferrous metals of the present invention has a convenient preparation process. It is used to generate a dense anti-corrosion coating in-situ again after the rusted iron-based metal surface is removed by acid, thereby effectively improving the corrosion resistance of the metal substrate.

[0116] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims.

Claims

1. An acidic water-based treatment agent for removing metal surface corrosion and simultaneously forming an anti-rust passivation layer, characterized in that the ingredients include: Polymaleic acid and its derivatives, zinc ions, and phosphate ions; in a water-based treatment agent, the solid content of the polymaleic acid and its derivatives is 0.01-50wt%, the molar concentration of the zinc ions is 0-2mol / L, and the molar concentration of the phosphate ions is 0-2mol / L.

2. The acidic water-based treatment agent according to claim 1, characterized in that In the water-based treatment agent, the solid content of the polymaleic acid and its derivatives is 1-20wt%, the molar concentration of the zinc ions is 0.01-1mol / L, and the molar concentration of the phosphate ions is 0.01-1mol / L.

3. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The polymaleic acid and its derivatives include at least one of polymaleic acid, styrene maleic acid copolymer, acrylic acid maleic acid copolymer, polypropylene maleic acid copolymer, polyisobutylene maleic acid copolymer, methyl vinyl ether maleic acid copolymer or polyisoprene maleic acid copolymer.

4. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The zinc salt used to prepare the acidic water-based treatment agent includes one or more of zinc phosphate, zinc sulfate, zinc nitrate, zinc lactate, zinc nicotinate, zinc citrate, zinc acetate or zinc gluconate.

5. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The phosphate used to prepare the acidic water-based treatment agent includes one or more of zinc phosphate, sodium phosphate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium phosphate, aminotrimethylene phosphate, ethylenediaminetetramethylene phosphate or hydroxyethylene diphosphate.

6. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The pH value of the acidic water-based treatment agent is 0.5-5.

0.

7. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The pH value of the acidic water-based treatment agent is 1.0-3.

0.

8. The acidic water-based treatment agent according to claim 1 or 2, characterized in that: The pH of the acidic water treatment agent is adjusted with an acidic solution, and the acidic solution includes at least one of sulfuric acid, nitric acid, phosphoric acid, acetic acid, citric acid, maleic acid, fumaric acid, formic acid, glutamic acid or 2-propionic acid.

9. A method for using the acidic water-based treatment agent according to any one of claims 1 to 8, comprising applying the acidic water-based treatment agent to the surface of a ferrous metal by one or more of spraying, spin coating, immersion, electrospraying, and brushing.

10. An application of the acidic water-based treatment agent according to any one of claims 1 to 8, which is suitable for alloys whose main components are iron, manganese, chromium and the three metals, and can form a new high-performance anti-corrosion passivation coating that is resistant to corrosion by acids, alkalis, salts, seawater, etc. while removing surface corrosion.

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