阅读说明：本技术 一种用于Ni-Cr-Mo合金钢焊接的低毒镍基焊条及其制备 (Low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel and preparation thereof ) 是由 苏东东 公茂涛 刘鑫 张敏娟 吴宝鑫 林永祥 于 2019-09-18 设计创作，主要内容包括：本发明涉及一种用于Ni-Cr-Mo合金钢焊接的低毒镍基焊条及其制备,焊条由焊芯以及裹覆在焊芯表面的药皮组成,所述药皮由粉料组分与粘结剂混合而成,所述粉料组分包括以焊芯重量百分比计算的以下成分：大理石15-20％,冰晶石9～15％,萤石3～5％,金红石10～16％,电解锰1～3％,铌铁2～7％,金属铬1～4％,纯碱0.1～0.5％,所述粘结剂为粉料组分总重量的15-25％。与现有技术相比,本发明制得的低毒镍基焊条具备焊接烟尘低毒、工艺性能优良、力学性能与母材接近。(The invention relates to a low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel and a preparation method thereof, wherein the welding rod consists of a core wire and a coating wrapped on the surface of the core wire, the coating is formed by mixing a powder component and a binder, and the powder component comprises the following components in percentage by weight of the core wire: 15-20% of marble, 9-15% of cryolite, 3-5% of fluorite, 10-16% of rutile, 1-3% of electrolytic manganese, 2-7% of ferroniobium, 1-4% of chromium metal and 0.1-0.5% of soda ash, wherein the binder accounts for 15-25% of the total weight of the powder components. Compared with the prior art, the low-toxicity nickel-based welding rod prepared by the invention has the advantages of low toxicity of welding fume, excellent processing performance and mechanical property close to that of a parent metal.)

1. The low-toxicity nickel-based welding rod for welding the Ni-Cr-Mo alloy steel is characterized by consisting of a core wire and a coating wrapped on the surface of the core wire, wherein the coating is formed by mixing a powder component and a binder, and the powder component comprises the following components in percentage by weight of the core wire: 15-20% of marble, 9-15% of cryolite, 3-5% of fluorite, 10-16% of rutile, 1-3% of electrolytic manganese, 2-7% of ferroniobium, 1-4% of chromium metal and 0.1-0.5% of soda ash, wherein the binder accounts for 15-25% of the total weight of the powder components.

2. The low toxicity nickel-based electrode for Ni-Cr-Mo alloy steel welding of claim 1, wherein said binder is water glass.

3. The low-toxicity nickel-based welding electrode for welding of Ni-Cr-Mo alloy steel according to claim 2, wherein said binder is sodium water glass, potassium water glass or potassium sodium water glass.

4. The low toxicity nickel-based electrode for Ni-Cr-Mo alloy steel welding of claim 1, wherein said core wire comprises the following components in weight percent: 0.01-0.08% of C, 0.10-0.80% of Mn, less than or equal to 0.005% of P, less than or equal to 0.006% of S, less than or equal to 0.10% of Si, 55.0-70.0% of Ni, 19.0-23.0% of Cr, 7.50-10.5% of Mo, less than or equal to 0.20% of Ti, less than or equal to 0.10% of Cu, less than or equal to 0.20% of Al, less than or equal to 8% of Fe, less than or equal to 0.03% of Co and 3.; o is less than or equal to 50ppm, and N is less than or equal to 40 ppm. The balance being impurities.

5. The low toxicity nickel-based electrode for Ni-Cr-Mo alloy steel welding of claim 1, wherein, in the marble, CaCO₃More than or equal to 97 wt%; in cryolite, Na₃AlF₆More than or equal to 97 wt%; in fluorite, CaF₂More than or equal to 95 wt%; TiO in rutile₂More than or equal to 95 wt%; in electrolytic manganese, Mn is more than or equal to 99.7 wt%; in the ferrocolumbium, the Nb content is more than or equal to 50wt percent, the Si content is less than or equal to 4wt percent, and the Al content is less than or equal to 2wt percent; in the metal chromium, Cr is more than or equal to 99 wt%; in sodium carbonate, Na₂CO₃≥99wt％。

6. The method of making a low toxicity nickel-based electrode for Ni-Cr-Mo alloy steel welding as defined in any of claims 1-5, comprising the steps of:

(1) uniformly mixing the powder components, adding a binder, and mixing to obtain a coating;

(2) and (2) coating the surface of the core wire with the coating prepared in the step (1), and baking to obtain the low-toxicity nickel-based welding rod.

7. The method for preparing a nickel-based welding rod with low toxicity for welding Ni-Cr-Mo alloy steel according to claim 6, wherein the baking process comprises a low temperature baking process and a high temperature baking process.

8. The method for preparing the low-toxicity nickel-based welding rod for welding the Ni-Cr-Mo alloy steel according to claim 7, wherein the low-temperature baking is carried out at 80-120 ℃ for 1-3 h;

the high-temperature baking temperature is 220-350 ℃, and the time is 0.5-1.5 h.

Technical Field

The invention belongs to the technical field of welding materials, and relates to a low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel and a preparation method thereof.

Background

Energy conservation and environmental protection are the problems generally concerned by countries in the world at present, and reduction of fuel consumption and reduction of CO must be considered in the design process of a thermal power station₂The emission needs to increase the steam temperature and pressure of the utility boiler, and further, higher requirements are put on key materials of the utility, especially the high-temperature strength, high-temperature corrosion resistance, oxidation resistance and the like of the materials. Among the nickel-based alloys, the UNS N06625 alloy belongs to a solid solution strengthening nickel-based alloy, has better high-temperature strength and oxidation resistance and corrosion resistance, and can be used as a candidate material of a new generation of ultra-supercritical unit.

The production and trade of Liquefied Natural Gas (LNG) is becoming more active and is becoming a new hot spot in the world's oil and Gas industry. In order to ensure diversified energy supply and improve energy consumption structure, some energy consumption countries pay more and more attention to the introduction of LNG, and LNG will become the next global popular energy commodity after petroleum. w (Ni) 9% steel is also called 9Ni steel or Ni9 steel, is w (Ni) 8.5% -9.5% ultralow temperature steel, and has the advantages of less alloy content and low price compared with stainless steel with excellent performance; compared with the low-temperature aluminum alloy, the alloy has the advantages of large allowable stress and small thermal expansion rate. The steel is widely used for constructing LNG storage tanks.

The welding rod for Ni-Cr-Mo alloy steel, such as the Ni-Cr-Mo alloy steel welding nickel-based welding rod disclosed in Chinese patent CN102430876A, is used for welding UNS N06625 and 9% Ni steel, and adopts marble, fluorite, barium carbonate, rutile, ferrocolumbium, chromium metal powder, soda ash, electrolytic manganese, zircon sand, binder and the like as raw materials. The welding rod adopts barium carbonate as a raw material, although the content of deposited metal impurities is reduced to a certain extent, the material belongs to barium salt, and has strong toxicity, for example, if the barium carbonate is accumulated on bones, the bone marrow leucocyte tissue hyperplasia is caused, and chronic poisoning is caused. And barium carbonate reacts with hydrochloric acid in gastric juice to become soluble barium chloride, which belongs to soluble barium salt and is a toxic substance, so that the barium chloride can be poisoned quickly if not rescued in time and can die in serious cases. The material has dangerous factors in the storage and use processes, which is not favorable for safe production and health of users.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel and a preparation method thereof.

The purpose of the invention can be realized by the following technical scheme:

one of the technical schemes of the invention is to provide a low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel, which consists of a core wire and a coating wrapped on the surface of the core wire, wherein the coating is formed by mixing a powder component and a binder, and the powder component comprises the following components in percentage by weight of the core wire: 15-20% of marble, 9-15% of cryolite, 3-5% of fluorite, 10-16% of rutile, 1-3% of electrolytic manganese, 2-7% of ferroniobium, 1-4% of chromium metal and 0.1-0.5% of soda ash, wherein the binder accounts for 15-25% of the total weight of the powder components.

Further, the binder is water glass.

Further, the binder is sodium water glass, potassium water glass or potassium sodium water glass.

Further, the core wire comprises the following components in percentage by weight: 0.01-0.08% of C, 0.10-0.80% of Mn, less than or equal to 0.005% of P, less than or equal to 0.006% of S, less than or equal to 0.10% of Si, 55.0-70.0% of Ni, 19.0-23.0% of Cr, 7.50-10.5% of Mo7, less than or equal to 0.20% of Ti, less than or equal to 0.10% of Cu, less than or equal to 0.20% of Al, less than or equal to 8% of Fe, less than or equal to 0.03% of Co and 3; o is less than or equal to 50ppm, and N is less than or equal to 40 ppm. The balance being impurities.

Further, in the marble, CaCO₃More than or equal to 97 wt%; in cryolite, Na₃AlF₆More than or equal to 97 wt%; in fluorite, CaF₂More than or equal to 95 wt%; TiO in rutile₂More than or equal to 95 wt%; in electrolytic manganese, Mn is more than or equal to 99.7 wt%; in the ferrocolumbium, the Nb content is more than or equal to 50wt percent, the Si content is less than or equal to 4wt percent, and the Al content is less than or equal to 2wt percent; in the metal chromium, Cr is more than or equal to 99 wt%; in sodium carbonate, Na₂CO₃≥99wt％。

The second technical scheme of the invention is to provide a preparation method of the low-toxicity nickel-based welding rod for welding Ni-Cr-Mo alloy steel, which comprises the following steps:

(1) uniformly mixing the powder components, adding a binder, and mixing to obtain a coating;

(2) and (2) coating the surface of the core wire with the coating prepared in the step (1), and baking to obtain the low-toxicity nickel-based welding rod.

Further, the baking treatment process comprises two procedures of low-temperature baking and high-temperature baking.

Further, the low-temperature baking temperature is 80-120 ℃, and the time is 1-3 h;

the high-temperature baking temperature is 220-350 ℃, and the time is 0.5-1.5 h.

The main functions of the components in the coating adopted by the invention are as follows:

and (3) marble: the method is mainly used for slagging and gas making, and welding seams are protected from being oxidized and nitrided by air; the melting point, viscosity, surface tension and interfacial tension of the slag can be adjusted.

Cryolite: the main functions are slagging, adjusting the physical property of the slag (the melting point of the slag is obviously reduced compared with fluorite), improving the processing property of the welding rod and being beneficial to reducing the diffusible hydrogen content of deposited metal. When the cryolite content is too high, the stability of the electric arc is deteriorated, and the slag adhesion phenomenon occurs; when the content is too low, the fluidity of the slag becomes difficult to control and the covering of the slag becomes poor, so that the amount of addition thereof is strictly controlled.

Fluorite: the surface tension of the liquid metal and the melting point of the slag can be reduced, the fluidity of the slag can be improved, the weld joint is attractive in appearance, the pore sensitivity of the weld joint is reduced, and the diffusible hydrogen content of the deposited metal can be reduced. The proper proportion of marble and fluorite is the key, and the stability of electric arc, the covering of slag and the slagging are better when the proportion is proper.

Rutile: the main functions are arc stabilization and slag forming, low-melting-point short slag is formed, the melting point, viscosity, surface tension and fluidity of the slag can be adjusted, the weld forming is improved, and splashing is reduced.

Electrolytic manganese: manganese element is mainly transited to the welding seam, so that the strength and the crack resistance of the welding seam are improved; secondly, the desulfurization and deoxidation functions are realized.

Ferrocolumbium: transition Nb elements are mainly added into deposited metal to meet the requirement on Nb content. Prevent the precipitation of harmful carbide, reduce the sensitivity of intergranular corrosion and reduce the tendency of hot cracking during welding.

Metallic chromium: chromium is mainly transited into the welding seam to supplement the burning loss in the welding core, thereby meeting the requirements of deposited metal components and improving the corrosion resistance.

Soda ash: the main function of the welding rod is to increase the smoothness and improve the press coating property of the welding rod, and the excessive addition amount is unfavorable for the press coating of the welding rod, so the addition amount is controlled.

Water glass: mainly as a binder, the water glass is beneficial to the stability of electric arc and is suitable for the press coating of the formula.

Core wire: by adopting ERNiCrMo-3, the impurity content is controlled, the S is less than or equal to 0.006 wt%, the P is less than or equal to 0.005 wt%, the O is less than or equal to 50ppm, and the N is less than or equal to 40ppm, so that the mechanical property of the deposited metal is ensured.

Compared with the prior art, the invention has the advantages of low toxicity of welding fume, excellent process performance and mechanical property close to that of the parent metal. The method is mainly used for welding Ni-Cr-Mo alloy, especially for welding and surfacing welding of UNS N06625 alloy and other steel grades and Ni-Cr-Mo composite steel, and can also be used for welding 9% Ni steel (such as ASTM A353 and A553).

Detailed Description

The present invention will be described in detail with reference to specific examples. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the following examples, unless otherwise specified, the starting materials and treatment techniques are all conventional and commercially available materials or conventional treatment techniques in the art.