阅读说明：本技术 一种耐腐蚀无缝不锈钢管及其加工工艺 (Corrosion-resistant seamless stainless steel pipe and processing technology thereof ) 是由 陈秋 黄胜波 于 2021-08-27 设计创作，主要内容包括：本申请涉及一种耐腐蚀无缝不锈钢管及其加工工艺,一种耐腐蚀无缝不锈钢管包括钢管本体,钢管本体的表面涂覆有耐腐蚀层,耐腐蚀层包括如下重量份数的组分：30-40份不饱和聚酯树脂；8-9份液体丁腈橡胶；10-12份椰油醇聚醚硫酸酯钠；1-2份催化剂；2-3份磷酸三油烯酯；1-2份硅藻土；1-2份锌粉；耐腐蚀无缝不锈钢管的加工工艺,包括耐腐蚀涂料制备和耐腐蚀层的涂覆。本申请具有以下优点和效果：将椰油醇聚醚硫酸酯钠与不饱和聚酯树脂混合,降低不饱和聚酯树脂的黏性同时提高固化效率,使不饱和聚酯树脂与液体丁腈橡胶均匀混合并紧密堆积形成致密结构,隔离腐蚀性物质对钢管的伤害；硅藻土和金属锌粉的进一步添加可增加耐腐蚀层的耐腐蚀性。(The application relates to a corrosion-resistant seamless stainless steel pipe and a processing technology thereof, the corrosion-resistant seamless stainless steel pipe comprises a steel pipe body, the surface of the steel pipe body is coated with a corrosion-resistant layer, and the corrosion-resistant layer comprises the following components in parts by weight: 30-40 parts of unsaturated polyester resin; 8-9 parts of liquid nitrile rubber; 10-12 parts of sodium coco-alcohol polyether sulfate; 1-2 parts of a catalyst; 2-3 parts of triolefin phosphate; 1-2 parts of diatomite; 1-2 parts of zinc powder; the processing technology of the corrosion-resistant seamless stainless steel pipe comprises the preparation of a corrosion-resistant coating and the coating of a corrosion-resistant layer. The application has the following advantages and effects: sodium coco-alcohol polyether sulfate is mixed with unsaturated polyester resin, so that the viscosity of the unsaturated polyester resin is reduced, the curing efficiency is improved, the unsaturated polyester resin and liquid nitrile rubber are uniformly mixed and closely stacked to form a compact structure, and the damage of corrosive substances to a steel pipe is isolated; the further addition of diatomaceous earth and metallic zinc powder may increase the corrosion resistance of the corrosion-resistant layer.)

1. The utility model provides a corrosion-resistant seamless stainless steel pipe, includes the steel pipe body, its characterized in that: the surface of the steel pipe body is coated with a corrosion-resistant layer, and the corrosion-resistant layer comprises the following components in parts by weight:

30-40 parts of unsaturated polyester resin;

8-9 parts of liquid nitrile rubber;

10-12 parts of sodium coco-alcohol polyether sulfate;

1-2 parts of a catalyst;

2-3 parts of triolefin phosphate;

1-2 parts of diatomite;

1-2 parts of zinc powder.

2. A corrosion resistant seamless stainless steel tube according to claim 1, wherein: the preparation method of the unsaturated polyester resin comprises the following steps: firstly, stirring 2-4 parts of terpene resin and 0.4-0.5 part of calcium oleate for reaction for 30-40min at 50-60 ℃ to obtain a resin mixture; adding 8-11 parts of diethylene glycol and 0.4-0.5 part of 4-methyl hexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at the temperature of 150 ℃ and 180 ℃, stopping the reaction after the reaction is performed for 1-1.5h, cooling to 80-90 ℃, and adding 4-5 parts of toluene; finally, 1-2 parts of 1, 4-cyclohexadiene are added and mixed evenly.

3. A corrosion resistant seamless stainless steel tube according to claim 1, wherein: according to the weight portion ratio, terpene resin: calcium oleate: diethylene glycol: 4-methylhexahydrophthalic anhydride =6:1:18: 1.

4. A corrosion resistant seamless stainless steel tube according to claim 1, wherein: the corrosion-resistant layer further comprises 2-3 parts by weight of lead isooctanoate and 5-6 parts by weight of polypropylene glycol diglycidyl ether.

5. A corrosion resistant seamless stainless steel tube according to claim 4, wherein: the corrosion-resistant layer also comprises 2-3 parts of dicyandiamide by weight.

6. A corrosion resistant seamless stainless steel tube according to claim 1, wherein: the catalyst is diketopiperazine.

7. The process of claim 1, comprising the steps of:

s1, preparing corrosion-resistant paint; firstly, mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 25-35min at the temperature of 30-40 ℃; then adding liquid nitrile rubber, heating to 90-100 ℃, and stirring for reaction for 1-1.5 h; finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 15-20min at the rotating speed of 500-600r/min, and continuously stirring for 25-30min to obtain the corrosion-resistant coating;

s2, coating a corrosion-resistant layer; heating the seamless stainless steel pipe to be coated to 150-200 ℃ in a heating furnace, taking out and placing, uniformly coating the corrosion-resistant coating prepared by S1 on the seamless stainless steel pipe with the thickness of 0.30-0.55mm to form a corrosion-resistant layer, and finally drying for 2-3h at the temperature of 50-60 ℃.

8. The process of claim 7, wherein the process comprises the following steps: the S1 further includes the steps of: firstly, stirring 2-4 parts of terpene resin and 0.4-0.5 part of calcium oleate for reaction for 30-40min at 50-60 ℃ to obtain a resin mixture; adding 8-11 parts of diethylene glycol and 0.4-0.5 part of 4-methyl hexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at the temperature of 150 ℃ and 180 ℃, stopping the reaction after the reaction is performed for 1-1.5h, cooling to 80-90 ℃, and adding 4-5 parts of toluene; finally, adding 1-2 parts of 1, 4-cyclohexadiene, and uniformly mixing to obtain unsaturated polyester resin;

mixing 5-6 parts of polypropylene glycol diglycidyl ether and 2-3 parts of dicyandiamide, stirring for 15-20min, adding 2-3 parts of lead isooctanoate, and continuously stirring for 10-15min to obtain a blend;

adding 8-9 parts of liquid nitrile rubber, heating to 90-100 ℃, stirring for reaction for 1-1.5h, cooling to 70-80 ℃, adding the blend, and stirring for 7-8 min; and finally, adding 1-2 parts of diatomite, 1-2 parts of zinc powder and 2-3 parts of triolefin phosphate which are stirred for 15-20min at the rotating speed of 500-600r/min, and continuously stirring for 25-30min to prepare the corrosion-resistant coating.

Technical Field

The application relates to the technical field of stainless steel pipes, in particular to a corrosion-resistant seamless stainless steel pipe and a processing technology thereof.

Background

In recent years, stainless steel pipes have become one of the fastest-developing varieties of steel products in China, and the application range of the stainless steel pipes is wider and wider, such as being widely used in fields of nuclear power stations, oil and gas exploitation, chemical industry, chemical fertilizers, environmental protection, automobiles, transportation, water supply, light industry, medicine, aviation, aerospace and the like; at present, the production process of the stainless steel seamless pipe mainly comprises hot extrusion, hot rolling, cold rolling and cold drawing.

The prior Chinese patent with the authorization publication number of CN112301288A discloses a method for processing an ultralong seamless stainless steel tube, which comprises the following steps: manufacturing a 0Cr18Ni10Ti stainless steel pipe blank; the tube blank comprises the following chemical components in parts by mass: the chemical components and the mass percentage are as follows: C. si, Mn, S, P, Cr, Ni, Nb, Mo, N, Ti, Sb, Pb, Ce, rare earth elements and the balance of Fe and inevitable impurities; the rare earth elements include: lanthanum, praseodymium, neodymium, samarium and yttrium, and the balance europium.

The above stainless steel pipes usually cause corrosion phenomena such as pitting corrosion and crevice corrosion due to improper maintenance or use, so the inventors believe that the current seamless stainless steel pipes still need to be improved.

Disclosure of Invention

In order to improve the corrosion resistance of the seamless stainless steel pipe, the application provides the corrosion-resistant seamless stainless steel pipe and the processing technology thereof.

In a first aspect, the corrosion-resistant seamless stainless steel tube provided by the application adopts the following technical scheme:

the corrosion-resistant seamless stainless steel pipe comprises a steel pipe body, wherein a corrosion-resistant layer is coated on the surface of the steel pipe body, and the corrosion-resistant layer comprises the following components in parts by weight:

30-40 parts of unsaturated polyester resin;

8-9 parts of liquid nitrile rubber;

10-12 parts of sodium coco-alcohol polyether sulfate;

1-2 parts of a catalyst;

2-3 parts of triolefin phosphate;

1-2 parts of diatomite;

1-2 parts of zinc powder.

By adopting the technical scheme, in the using process of the stainless steel pipe, corrosion and abrasion have interaction, the corrosion can accelerate the abrasion, the abrasion can accelerate the corrosion in turn, and the unsaturated polyester resin and the liquid nitrile rubber are mixed to improve the abrasion resistance of the corrosion-resistant layer; meanwhile, the addition of the triolefin phosphate and the unsaturated polyester resin is beneficial to improving the coagulation and drying speed of the corrosion-resistant layer after coating, and simultaneously the cured corrosion-resistant layer has better flexibility and weather resistance, thereby achieving the purposes of reducing the abrasion of the steel pipe and enhancing the corrosion resistance; in addition, under the action of a catalyst, sodium cocoalcohol polyether sulfate is mixed with unsaturated polyester resin, and the product obtained by reaction can reduce the viscosity of the unsaturated polyester resin on one hand and improve the curing efficiency on the other hand, so that the unsaturated polyester resin and liquid nitrile rubber are uniformly mixed and tightly stacked to form a compact structure, and the damage of corrosive substances to a steel pipe is isolated; the further addition of diatomaceous earth and metallic zinc powder may increase the corrosion resistance of the corrosion-resistant layer.

Preferably, the preparation method of the unsaturated polyester resin comprises the following steps: firstly, stirring 2-4 parts of terpene resin and 0.4-0.5 part of calcium oleate for reaction for 30-40min at 50-60 ℃ to obtain a resin mixture; adding 8-11 parts of diethylene glycol and 0.4-0.5 part of 4-methyl hexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at the temperature of 150 ℃ and 180 ℃, stopping the reaction after the reaction is performed for 1-1.5h, cooling to 80-90 ℃, and adding 4-5 parts of toluene; finally, 1-2 parts of 1, 4-cyclohexadiene are added and mixed evenly.

By adopting the technical scheme, the high molecular compound terpene resin has the advantages of high hardness, high adhesive force, good oxidation resistance and compatibility and the like, and the unsaturated polyester resin prepared by mixing the diglycol, the terpene resin, the calcium oleate and the 4-methylhexahydrophthalic anhydride can increase the steric hindrance and reduce the ester group concentration in the unsaturated polyester resin, thereby improving the corrosion resistance and further improving the corrosion resistance of the steel pipe.

Preferably, the terpene resin: calcium oleate: diethylene glycol: 4-methylhexahydrophthalic anhydride =6:1:18: 1.

By adopting the technical scheme, tests prove that the corrosion resistance is better when the weight part ratio of the terpene resin, the calcium oleate, the diethylene glycol and the 4-methyl hexahydrophthalic anhydride is 6:1:18: 1.

Preferably, the corrosion-resistant layer further comprises 2-3 parts by weight of lead isooctanoate and 5-6 parts by weight of polypropylene glycol diglycidyl ether.

By adopting the technical scheme, the corrosion resistance can be further improved by adding the metal compound lead isooctanoate, a tough and continuous protective layer can be formed, and the purpose of inhibiting corrosion is achieved.

Preferably, the corrosion-resistant layer further comprises 2-3 parts by weight of dicyandiamide.

By adopting the technical scheme, the dicyandiamide has a curing effect, the dicyandiamide and the polypropylene glycol diglycidyl ether are mixed to promote the curing of the corrosion-resistant layer, and the obtained product can be tightly adhered to the stainless steel pipe to form a firm protective film, so that the corrosion resistance of the steel pipe is improved.

Preferably, the catalyst is a diketopiperazine.

In a second aspect, the present application provides a process for processing a corrosion-resistant seamless stainless steel tube, which adopts the following technical scheme:

a processing technology of a corrosion-resistant seamless stainless steel pipe comprises the following steps:

s1, preparing corrosion-resistant paint; firstly, mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 25-35min at the temperature of 30-40 ℃; then adding liquid nitrile rubber, heating to 90-100 ℃, and stirring for reaction for 1-1.5 h; and finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 15-20min at the rotating speed of 500-600r/min, and continuously stirring for 25-30min to obtain the corrosion-resistant coating.

S2, coating a corrosion-resistant layer; heating the seamless stainless steel pipe to be coated to 150-200 ℃ in a heating furnace, taking out and placing, uniformly coating the corrosion-resistant coating prepared by S1 on the seamless stainless steel pipe with the thickness of 0.30-0.55mm to form a corrosion-resistant layer, and finally drying for 2-3h at the temperature of 50-60 ℃.

Preferably, the S1 further includes the following steps: firstly, stirring 2-4 parts of terpene resin and 0.4-0.5 part of calcium oleate for reaction for 30-40min at 50-60 ℃ to obtain a resin mixture; adding 8-11 parts of diethylene glycol and 0.4-0.5 part of 4-methyl hexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at the temperature of 150 ℃ and 180 ℃, stopping the reaction after the reaction is performed for 1-1.5h, cooling to 80-90 ℃, and adding 4-5 parts of toluene; finally, adding 1-2 parts of 1, 4-cyclohexadiene, and uniformly mixing to obtain unsaturated polyester resin;

mixing 5-6 parts of polypropylene glycol diglycidyl ether and 2-3 parts of dicyandiamide, stirring for 15-20min, adding 2-3 parts of lead isooctanoate, and continuously stirring for 10-15min to obtain a blend;

adding 8-9 parts of liquid nitrile rubber, heating to 90-100 ℃, stirring for reaction for 1-1.5h, cooling to 70-80 ℃, adding the blend, and stirring for 7-8 min; and finally, adding 1-2 parts of diatomite, 1-2 parts of zinc powder and 2-3 parts of triolefin phosphate which are stirred for 15-20min at the rotating speed of 500-600r/min, and continuously stirring for 25-30min to prepare the corrosion-resistant coating.

To sum up, the application comprises the following beneficial technical effects:

1. under the action of a catalyst, sodium cocoanut oil alcohol polyether sulfate is mixed with unsaturated polyester resin, the product obtained by reaction can reduce the viscosity of the unsaturated polyester resin on one hand and improve the curing efficiency on the other hand, so that the unsaturated polyester resin and liquid nitrile rubber are uniformly mixed and closely stacked to form a compact structure, the triolefin phosphate and the unsaturated polyester resin enable the cured corrosion-resistant layer to have better flexibility and weather resistance, and diatomite and zinc powder are further added, so that the damage of corrosive substances to the steel pipe is isolated, and the corrosion resistance of the seamless stainless steel pipe is improved;

2. according to the unsaturated polyester resin, the advantages of high hardness, high adhesive force, good oxidation resistance and compatibility of the high molecular compound terpene resin are utilized, diethylene glycol, the terpene resin, calcium oleate and 4-methyl hexahydrophthalic anhydride are mixed for preparation, the steric hindrance can be increased, the ester group concentration in the unsaturated polyester resin is reduced, the corrosion resistance is improved, and the corrosion resistance of a steel pipe is improved;

3. the addition of the metal compound lead isooctanoate can further improve the corrosion resistance, form a tough and continuous protective layer and achieve the purpose of inhibiting corrosion, the addition of the polypropylene glycol diglycidyl ether can reduce the interfacial tension, promote the improvement of the dispersion degree of the lead isooctanoate and improve the stability of phase morphology, and the dicyandiamide and the polypropylene glycol diglycidyl ether are mixed, so that the obtained product can be tightly adhered with a stainless steel pipe to form a firm protective film, and the purpose of improving the corrosion resistance of the seamless stainless steel pipe is achieved.

Detailed Description

The present application is described in further detail below.

In the application, the liquid nitrile rubber is produced by denna sanderi chemical limited; sodium cocoeth sulfate was produced by modest and chemical co ltd, southwest city; the terpene resin is produced by Shandong Liang New Material science and technology Limited company, and is brand T-100; diatomaceous earth is produced by Jiangsu Qiangsheng functional chemical corporation; polypropylene glycol diglycidyl ether is produced by west asia chemical technology (Shandong) Co., Ltd.

The raw materials used in the following embodiments may be those conventionally commercially available unless otherwise specified.

Examples

Example 1

The application discloses a corrosion-resistant seamless stainless steel pipe and a preparation method thereof; the utility model provides a corrosion-resistant seamless nonrust steel pipe, includes the steel pipe body, and the surface coating of steel pipe body has corrosion-resistant layer, and corrosion-resistant layer includes following component: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolefin phosphate, diatomite and zinc powder; wherein, the catalyst is diketopiperazine, and the adopted unsaturated polyester resin has the following preparation method:

firstly, stirring 2 parts of terpene resin and 0.4 part of calcium oleate for reaction for 30min at 50 ℃ to obtain a resin mixture; adding 8 parts of diethylene glycol and 0.4 part of 4-methylhexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at 150 ℃, stopping the reaction after the reaction is performed for 1 hour, cooling to 80 ℃, and adding 4 parts of toluene; finally, 1 part of 1, 4-cyclohexadiene is added and mixed evenly.

The contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps:

s1, preparing corrosion-resistant paint; firstly, mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 25min at the temperature of 30 ℃; then adding liquid nitrile rubber, heating to 90 ℃, and stirring for reaction for 1 h; finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 15min at the rotating speed of 500r/min, and continuously stirring for 25min to obtain the corrosion-resistant coating;

s2, coating a corrosion-resistant layer; and (3) heating the seamless stainless steel pipe to be coated to 150 ℃ in a heating furnace, taking out and placing, uniformly coating the corrosion-resistant coating prepared in the step (S1) on the seamless stainless steel pipe to form a corrosion-resistant layer with the thickness of 0.30mm, and finally drying for 2 hours at the temperature of 50 ℃.

Example 2

The application discloses a corrosion-resistant seamless stainless steel pipe and a preparation method thereof; the utility model provides a corrosion-resistant seamless nonrust steel pipe, includes the steel pipe body, and the surface coating of steel pipe body has corrosion-resistant layer, and corrosion-resistant layer includes following component: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolefin phosphate, diatomite and zinc powder; wherein, the catalyst is diketopiperazine, and the adopted unsaturated polyester resin has the following preparation method:

firstly, stirring 4 parts of terpene resin and 0.5 part of calcium oleate for reaction for 40min at 60 ℃ to obtain a resin mixture; adding 11 parts of diethylene glycol and 0.5 part of 4-methylhexahydrophthalic anhydride into the resin mixture, mixing, performing polycondensation at 180 ℃, stopping the reaction after reacting for 1.5h, cooling to 90 ℃, and adding 5 parts of toluene; finally, 2 parts of 1, 4-cyclohexadiene are added and mixed uniformly.

The contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps:

s1, preparing corrosion-resistant paint; firstly, mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 35min at 40 ℃; then adding liquid nitrile rubber, heating to 100 ℃, and stirring for reaction for 1.5 h; finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 20min at the rotating speed of 600r/min, and continuously stirring for 30min to obtain the corrosion-resistant coating;

s2, coating a corrosion-resistant layer; and heating the seamless stainless steel pipe to be coated to 200 ℃ in a heating furnace, taking out and placing, uniformly coating the corrosion-resistant coating prepared in the step S1 on the seamless stainless steel pipe to form a corrosion-resistant layer with the thickness of 0.55mm, and finally drying for 3 hours at the temperature of 60 ℃.

Example 3

The application discloses a corrosion-resistant seamless stainless steel pipe and a preparation method thereof; the utility model provides a corrosion-resistant seamless nonrust steel pipe, includes the steel pipe body, and the surface coating of steel pipe body has corrosion-resistant layer, and corrosion-resistant layer includes following component: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolefin phosphate, diatomite and zinc powder; wherein, the catalyst is diketopiperazine, and the adopted unsaturated polyester resin has the following preparation method:

firstly, stirring 3 parts of terpene resin and 0.4 part of calcium oleate for reaction for 35min at 55 ℃ to obtain a resin mixture; then adding 10 parts of diethylene glycol and 0.4 part of 4-methyl hexahydrophthalic anhydride into the resin mixture, mixing, carrying out polycondensation at 160 ℃, stopping the reaction after reacting for 1.2h, cooling to 85 ℃, and then adding 5 parts of toluene; finally, 2 parts of 1, 4-cyclohexadiene are added and mixed uniformly.

The contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps:

s1, preparing corrosion-resistant paint; firstly, mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 30min at 35 ℃; then adding liquid nitrile rubber, heating to 95 ℃, and stirring for reaction for 1.2 h; finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 18min at the rotating speed of 560r/min, and continuously stirring for 28min to obtain the corrosion-resistant coating;

s2, coating a corrosion-resistant layer; and heating the seamless stainless steel pipe to be coated to 180 ℃ in a heating furnace, taking out and placing, uniformly coating the corrosion-resistant coating prepared in the step S1 on the seamless stainless steel pipe to form a corrosion-resistant layer with the thickness of 0.40mm, and finally drying for 2.5 hours at the temperature of 55 ℃.

Example 4

The difference from the embodiment 1 is that a corrosion-resistant seamless stainless steel pipe comprises a steel pipe body, the surface of the steel pipe body is coated with a corrosion-resistant layer, and the corrosion-resistant layer comprises the following components: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolein phosphate, diatomite, zinc powder, lead isooctanoate, polypropylene glycol diglycidyl ether and dicyandiamide; wherein the catalyst is diketopiperazine; the contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps of S1:

mixing and stirring polypropylene glycol diglycidyl ether and dicyandiamide for 15min, adding lead isooctanoate, and continuously stirring for 10min to obtain a blend;

then mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 25min at the temperature of 30 ℃; then adding liquid nitrile rubber, heating to 90 ℃, and stirring for reaction for 1 h; cooling to 70 deg.C, adding the blend, and stirring for 7 min; and finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 15min at the rotating speed of 500r/min, and continuously stirring for 25min to prepare the corrosion-resistant coating.

Example 5

The difference from the embodiment 2 is that the corrosion-resistant seamless stainless steel pipe comprises a steel pipe body, wherein the surface of the steel pipe body is coated with a corrosion-resistant layer, and the corrosion-resistant layer comprises the following components: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolein phosphate, diatomite, zinc powder, lead isooctanoate, polypropylene glycol diglycidyl ether and dicyandiamide; wherein the catalyst is diketopiperazine; the contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps of S1:

mixing and stirring polypropylene glycol diglycidyl ether and dicyandiamide for 20min, adding lead isooctanoate, and continuously stirring for 15min to obtain a blend;

then mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 35min at 40 ℃; then adding liquid nitrile rubber, heating to 100 ℃, and stirring for reaction for 1.5 h; cooling to 80 deg.C, adding the blend, and stirring for 8 min; and finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 20min at the rotating speed of 600r/min, and continuously stirring for 30min to prepare the corrosion-resistant coating.

Example 6

The difference from the embodiment 3 is that the corrosion-resistant seamless stainless steel pipe comprises a steel pipe body, wherein the surface of the steel pipe body is coated with a corrosion-resistant layer, and the corrosion-resistant layer comprises the following components: unsaturated polyester resin, liquid nitrile rubber, sodium coco-alcohol polyether sulfate, a catalyst, triolein phosphate, diatomite, zinc powder, lead isooctanoate, polypropylene glycol diglycidyl ether and dicyandiamide; wherein the catalyst is diketopiperazine; the contents of the components are shown in table 1 below.

A preparation method of a corrosion-resistant seamless stainless steel pipe comprises the following steps of S1:

mixing and stirring polypropylene glycol diglycidyl ether and dicyandiamide for 18min, adding lead isooctanoate, and continuously stirring for 12min to obtain a blend;

then mixing sodium coco-alcohol polyether sulfate with unsaturated polyester resin, adding a catalyst, and stirring for 30min at 35 ℃; then adding liquid nitrile rubber, heating to 95 ℃, and stirring for reaction for 1.2 h; cooling to 75 deg.C, adding the blend, and stirring for 8 min; and finally, adding the diatomite, the zinc powder and the triolefin phosphate which are stirred for 18min at the rotating speed of 560r/min, and continuously stirring for 28min to prepare the corrosion-resistant coating.

Example 7

The difference from the embodiment 1 is that, according to the weight portion ratio, the terpene resin: calcium oleate: diethylene glycol: 4-methyl hexahydrophthalic anhydride =6:1:18:1, namely 3 parts of terpene resin, 0.5 part of calcium oleate, 9 parts of diethylene glycol and 0.5 part of 4-methyl hexahydrophthalic anhydride.

Example 8

The difference from example 1 is that the components of the corrosion-resistant layer further include lead isooctanoate and polypropylene glycol diglycidyl ether, and the contents of the components are shown in table 2 below.

Example 9

The difference from example 8 is that lead isooctanoate was replaced with calcium carbonate, and the contents of the respective components are shown in table 2 below.

Example 10

The difference from example 4 is that the polypropylene glycol diglycidyl ether is replaced with glycerin, and the contents of the respective components are shown in table 2 below.

Example 11

The difference from example 4 is that dicyandiamide is replaced with p-hydroxybenzene sulfonic acid, and the contents of the components are shown in table 2 below.

Example 12

The difference from example 1 is that the catalyst diketopiperazine was replaced by tetrabutyltitanate.

Comparative example

Comparative example 1

The difference from example 1 is that the stainless steel pipe is not coated with a corrosion-resistant layer.

Comparative example 2

The difference from example 1 is that the unsaturated polyester resin is prepared by the following method: mixing 8 parts of propylene glycol and 2.8 parts of maleic anhydride, carrying out polycondensation at 150 ℃, stopping the reaction after 1 hour of reaction, cooling to 80 ℃, and adding 4 parts of toluene; and finally, adding 1 part of styrene and uniformly mixing. The contents of the respective components are shown in the following table 3.

Comparative example 3

The difference from example 1 is that sodium cocoeth sulfate was replaced with styrene and the component contents are shown in table 3 below.

Comparative example 4

The difference from example 1 is that the liquid nitrile rubber was replaced with an epoxy resin and the contents of the components are shown in table 3 below.

Comparative example 5

The difference from example 1 is that triolefin phosphate is replaced by diphenyl phosphate and the contents of each component are shown in table 3 below.

Comparative example 6

The difference from example 1 is that, without adding diatomaceous earth, the contents of each component are shown in table 3 below.

TABLE 1 component content tables of examples 1 to 6 and comparative examples 3 to 6

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							Unsaturated polyester resin	30	40	35	30	40	35
Liquid nitrile rubber	8	9	9	8	9	9
							Sodium coco-alcohol polyether sulfate	5	6	5	5	6	5
Catalyst and process for preparing same	1	2	2	1	2	2
							Triolefin phosphate ester	2	3	2	2	3	2
Diatomite	1	2	2	1	2	2
							Zinc powder	1	2	1	1	2	1
Lead isooctoate	/	/	/	2	3	2
							Polypropylene glycol diglycidyl ether	/	/	/	5	6	6
Dicyandiamide	/	/	/	2	3	3

TABLE 2 ingredient content tables for examples 8-12

	Example 8	Example 9	Example 10	Example 11	Example 12
						Unsaturated polyester resin	30	30	30	30	30
Liquid nitrile rubber	8	8	8	8	8
						Sodium coco-alcohol polyether sulfate	5	5	5	5	5
Catalyst and process for preparing same	1	1	1	1	1
						Triolefin phosphate ester	2	2	2	2	2
Diatomite	1	1	1	1	1
						Zinc powder	1	1	1	1	1
Lead isooctanoate/calcium carbonate	2	2	2	2	/
						Polypropylene glycol diglycidyl ether/glycerol	5	5	5	5	/
Dicyandiamide/p-hydroxybenzenesulfonic acid	/	/	2	2	/

TABLE 3 ingredient content of comparative examples 2 to 6

	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6
						Unsaturated polyester resin	30	30	30	30	30
Liquid nitrile rubber/epoxy resin	8	8	8	8	8
						Sodium coco-alcohol polyether sulfate/styrene	5	5	5	5	5
Catalyst and process for preparing same	1	1	1	1	1
						Triolefin phosphate/diphenyl phosphate	2	2	2	2	2
Diatomite	1	1	1	1	/
						Zinc powder	1	1	1	1	1

Performance test

The seamless stainless steel pipes of each example and comparative example were processed into samples of 60mm × 60mm × 2mm, and the samples of each example and comparative example were subjected to a corrosion resistance test by the following test method: according to the requirements of GB/T10125-.

TABLE 4 Corrosion resistance test results of examples and comparative examples

	Weight loss/g
		Example 1	0.40
Example 2	0.31
		Example 3	0.35
Example 4	0.20
		Example 5	0.10
Example 6	0.16
		Example 7	0.33
Example 8	0.36
		Example 9	0.40
Example 10	0.23
		Example 11	0.27
Example 12	0.42
		Comparative example 1	0.55
Comparative example 2	0.49
		Comparative example 3	0.42
Comparative example 4	0.45
		Comparative example 5	0.43
Comparative example 6	0.44

In summary, the following conclusions can be drawn:

1. as can be seen from examples 1 and 7 in combination with table 4, when the weight part ratio of the terpene resin, calcium oleate, diethylene glycol, and 4-methylhexahydrophthalic anhydride is 6:1:18:1, the corrosion resistance effect of the corrosion-resistant layer can be improved well, and the corrosion resistance of the seamless stainless steel pipe can be improved.

2. As can be seen from examples 1 and 8 to 9 in combination with table 4, the corrosion resistance of the corrosion-resistant layer was improved to some extent by adding lead isooctanoate in combination with polypropylene glycol diglycidyl ether, and the corrosion resistance of the seamless stainless steel pipe was improved.

3. As can be seen from example 4 and examples 10 to 11 in combination with table 4, the co-addition of polypropylene glycol diglycidyl ether and dicyandiamide has a synergistic effect on enhancing the corrosion resistance of the corrosion-resistant layer.

4. As can be seen from example 1 and comparative example 1 in combination with table 4, the seamless stainless steel pipe coated with the corrosion-resistant layer of the present application has high corrosion resistance.

5. According to example 1 and comparative examples 2-3 in combination with Table 4, it can be seen that the co-addition of the unsaturated polyester resin and sodium coco-polyether sulfate used in the present application has a synergistic effect, which results in a seamless stainless steel pipe with high corrosion resistance.

6. According to the embodiment 1 and the comparative examples 2 and 4, and the combination of the liquid nitrile rubber and the unsaturated polyester resin, the corrosion resistance of the corrosion-resistant layer can be effectively improved by blending the liquid nitrile rubber and the unsaturated polyester resin, so that the corrosion resistance of the seamless stainless steel pipe is improved.

7. According to example 1 and comparative examples 5 and 6, and in combination with table 4, it can be seen that the addition of triolefin phosphate and diatomite has a certain effect on improving the corrosion resistance of the corrosion-resistant layer, and assists in improving the corrosion resistance of the seamless stainless steel pipe.

The present embodiment is only for explaining the present application, and the protection scope of the present application is not limited thereby, and those skilled in the art can make modifications to the present embodiment without inventive contribution as needed after reading the present specification, but all are protected by patent law within the scope of the claims of the present application.