阅读说明：本技术 一种超低碳耐高温焊丝及其制备方法 (ultralow-carbon high-temperature-resistant welding wire and preparation method thereof ) 是由 毛兰秀 于 2019-09-27 设计创作，主要内容包括：本发明涉及一种超低碳耐高温焊丝及其制备方法,超低碳耐高温焊丝的化学组分按照质量百分比计：C为0.01～0.04%,Cr为22.0～24.0%,Si为1.5～3.5%,Ni为12.0～14.0%,Ti为0.5～1.2%,Mn为0.1～0.4%,Zr为0.2～0.5%,Sc为0.3～0.6%,Mo为0.1～0.3%,Nb为0.3～0.5%,Mg为3.0～5.0%,Al为0.6～1.2%,P为0.03～0.07%,S为0.02～0.05%,V为0.2～0.4%,B为1.3～1.6%,余量为Fe及其它不可避免的杂质元素。本发明在保证焊丝低碳的同时,能够提高焊丝的力学性能。(The invention relates to an ultra-low carbon high temperature resistant welding wire and a preparation method thereof, wherein the ultra-low carbon high temperature resistant welding wire comprises the following chemical components in percentage by mass: 0.01 to 0.04% of C, 22.0 to 24.0% of Cr, 1.5 to 3.5% of Si, 12.0 to 14.0% of Ni, 0.5 to 1.2% of Ti, 0.1 to 0.4% of Mn, 0.2 to 0.5% of Zr, 0.3 to 0.6% of Sc, 0.1 to 0.3% of Mo, 0.3 to 0.5% of Nb, 3.0 to 5.0% of Mg, 0.6 to 1.2% of Al, 0.03 to 0.07% of P, 0.02 to 0.05% of S, 0.2 to 0.4% of V, 1.3 to 1.6% of B, and the balance of Fe and other inevitable impurity elements. The invention can improve the mechanical property of the welding wire while ensuring the low carbon of the welding wire.)

1. An ultra-low carbon high temperature resistant welding wire is characterized in that: the chemical components of the ultra-low carbon high temperature resistant welding wire are as follows by mass percent: 0.01 to 0.04% of C, 22.0 to 24.0% of Cr, 1.5 to 3.5% of Si, 12.0 to 14.0% of Ni, 0.5 to 1.2% of Ti, 0.1 to 0.4% of Mn, 0.2 to 0.5% of Zr, 0.3 to 0.6% of Sc, 0.1 to 0.3% of Mo, 0.3 to 0.5% of Nb, 3.0 to 5.0% of Mg, 0.6 to 1.2% of Al, 0.03 to 0.07% of P, 0.02 to 0.05% of S, 0.2 to 0.4% of V, 1.3 to 1.6% of B, and the balance of Fe and other inevitable impurity elements.

2. The ultra-low carbon high temperature resistant welding wire of claim 1, wherein: the chemical components of the ultra-low carbon high temperature resistant welding wire are as follows by mass percent: 0.02% of C, 23.5% of Cr, 2.5% of Si, 13.2% of Ni, 0.8% of Ti, 0.28% of Mn, 0.35% of Zr, 0.45% of Sc, 0.22% of Mo, 0.41% of Nb, 4.3% of Mg, 0.9% of Al, 0.05% of P, 0.04% of S, 0.33% of V, 1.45% of B, and the balance of Fe and other unavoidable impurity elements.

3. the ultra-low carbon high temperature resistant welding wire of claim 1, wherein: the chemical components of the ultra-low carbon high temperature resistant welding wire are as follows by mass percent: 0.03% of C, 22.8% of Cr, 2.8% of Si, 13.6% of Ni, 0.6% of Ti, 0.35% of Mn, 0.41% of Zr, 0.52% of Sc, 0.22% of Mo, 0.41% of Nb, 4.3% of Mg, 0.9% of Al, 0.05% of P, 0.04% of S, 0.33% of V, 1.45% of B, and the balance of Fe and other unavoidable impurity elements.

4. A preparation method of an ultra-low carbon high temperature resistant welding wire is characterized by comprising the following steps: the method specifically comprises the following steps:

Step 1, ingredient smelting: weighing the components according to the proportion, and then adding the components into a heating furnace for smelting;

step 2, refining: after all the components in the heating furnace are completely melted, adding a refining agent, and uniformly stirring, wherein the refining agent accounts for 0.3-0.5% of the total mass of the alloy liquid;

Step 3, casting: and (3) standing for 10-30 min after refining, removing molten slag on the surface of the alloy liquid, and casting into ingots:

Step 4, preparing a wire blank: heating the cast ingot, and performing hot extrusion to obtain a line blank;

Step 5, drawing: drawing the wire blank prepared in the step 4 through a wire drawing machine, then performing intermediate annealing, and continuing to draw the wire blank to a certain specification;

step 6, welding wire surface treatment: and carrying out acid washing, polishing and passivation treatment on the surface of the welding wire to obtain the finished welding wire.

5. the method for preparing the ultra-low carbon high temperature resistant welding wire according to claim 4, wherein: the smelting temperature in the step 1 is 1850-1950 ℃.

6. The method for preparing the ultra-low carbon high temperature resistant welding wire according to claim 4, wherein: the refining temperature in the step 2 is 1600-1700 ℃.

7. the method for preparing the ultra-low carbon high temperature resistant welding wire according to claim 4, wherein: the acid washing solution in the step 6 is a sulfuric acid solution with the mass fraction of 15-20%, the acid washing temperature is 30-50 ℃, and the acid washing time is 2-5 min.

Technical Field

The invention relates to the technical field of welding wires, in particular to an ultra-low-carbon high-temperature-resistant welding wire and a preparation method thereof.

Background

The wire is used as a filler metal or as a conductive wire welding material, and is used as a filler metal in gas welding and gas tungsten arc welding, and is used as a filler metal and a conductive electrode in submerged arc welding, electroslag welding, and other gas metal arc welding. Stainless steel has good corrosion resistance, durability, wear resistance and other properties, and is widely applied in various fields, stainless steel needs to be welded in order to meet large-size requirements in the industrial application process, and intergranular corrosion of stainless steel welding seams is a great problem in the chemical industry.

at room temperature, the solubility of carbon in stainless steel is small, about 0.02-0.03%, and the content of carbon in general stainless steel exceeds this value, so that the excessive carbon continuously diffuses to the grain boundaries of the stainless steel and combines with chromium, and compounds of chromium formed in the intergranular region, such as (CrFe) ₂₃ C ₆, lead to the reduction of chromium content near the grain boundaries, and generate intergranular corrosion.

the carbon content in the welding wire is reduced, the carbon content in a welding seam can be effectively reduced, but the carbon content in the welding wire is reduced to influence the mechanical property of the welding wire, so that the problem to be solved at present is to improve the mechanical property of the welding wire while ensuring the low carbon of the welding wire.

Disclosure of Invention

The invention aims to provide an ultra-low-carbon high-temperature-resistant welding wire, which can improve the mechanical property of the welding wire while ensuring the low carbon of the welding wire; the invention also aims to provide a preparation method of the ultralow-carbon high-temperature-resistant welding wire.

The technical purpose of the invention is realized by the following technical scheme: an ultra-low carbon high temperature resistant welding wire comprises the following chemical components in percentage by mass: 0.01 to 0.04% of C, 22.0 to 24.0% of Cr, 1.5 to 3.5% of Si, 12.0 to 14.0% of Ni, 0.5 to 1.2% of Ti, 0.1 to 0.4% of Mn, 0.2 to 0.5% of Zr, 0.3 to 0.6% of Sc, 0.1 to 0.3% of Mo, 0.3 to 0.5% of Nb, 3.0 to 5.0% of Mg, 0.6 to 1.2% of Al, 0.03 to 0.07% of P, 0.02 to 0.05% of S, 0.2 to 0.4% of V, 1.3 to 1.6% of B, and the balance of Fe and other inevitable impurity elements.

By adopting the technical scheme, the ultra-low carbon content can reduce and avoid forming chromium compounds at a welding seam, thereby reducing the intergranular corrosion of stainless steel, improving the strength of the stainless steel, prolonging the service life of the stainless steel, adding Si, reducing the melting point of the alloy, and having small linear expansion coefficient, so that the alloy is not easy to generate crystal cracks, and has good weldability and casting property after melting, in addition, Si is used as a deoxidizing element, can prevent iron from being combined with oxidation, can reduce FeO.Ti, Zr, Sc, V and B in a heating furnace, is beneficial to improving the performance of the welding seam, refines crystal grains of crack metal, reduces the tendency of generating welding cracks during welding, can improve the ductility and toughness of the welding seam, and adding a small amount of Ti can enable alloy steel to precipitate an initial TiO ₃ phase from a melt during the solidification process, the grains are very close to an alpha (Al) matrix in the lattice structure and size, is a good substrate on which Al atoms are accumulated, can provide a core for the alpha (Al) matrix, thereby refining the grain structure, adding Sc, ₃ grains, and secondary fine grains are added, and Sc are added to strengthen the alloy, so that the Sc and Sc are added to strengthen the alloy, so that the alloy has strong dispersion strengthening effect of strengthening the Al grains and the strengthening effect of strengthening the strengthening of strengthening Al 6335 and strengthening.

Mn plays roles of microalloying and strengthening and toughening, and can also improve the stress corrosion resistance of alloy steel, and the addition of Mn can ensure that Mg phase is uniformly precipitated, so that the corrosion sensitivity of the alloy steel is reduced, particularly the stress corrosion cracking resistance is obviously improved, and the mechanical property of a welding line is improved. Mo in the alloy steel can improve the strength and hardness of the steel, refine crystal grains, prevent the tempering brittleness and overheating tendency, improve the plasticity of the alloy steel, reduce the tendency of generating cracks and improve the impact toughness.

After Mg is added, Mg and Si atoms are gathered on a crystal face of a substrate to form a solute atom enrichment area, the Mg and Si atoms are further enriched and tend to be ordered along with the increase of aging temperature and the extension of time, the atoms rapidly grow into a needle shape or a rod shape, the Mg and the Si can form a beta (Mg ₂ Si) strengthening phase to improve the tensile strength of the welding wire, and meanwhile, the addition of the Mg can also enable the surface of the prepared welding wire to be smooth and clean, the deformation resistance of the alloy in the preparation process of the welding wire is increased along with the increase of the Mg content, the Mg content is high, the forming processing of the welding wire is not facilitated, and therefore the Mg content is 3.0-.

The invention is further provided with: the chemical components of the ultra-low carbon high temperature resistant welding wire are as follows by mass percent: 0.02% of C, 23.5% of Cr, 2.5% of Si, 13.2% of Ni, 0.8% of Ti, 0.28% of Mn, 0.35% of Zr, 0.45% of Sc, 0.22% of Mo, 0.41% of Nb, 4.3% of Mg, 0.9% of Al, 0.05% of P, 0.04% of S, 0.33% of V, 1.45% of B, and the balance of Fe and other unavoidable impurity elements.

The invention is further provided with: the chemical components of the ultra-low carbon high temperature resistant welding wire are as follows by mass percent: 0.03% of C, 22.8% of Cr, 2.8% of Si, 13.6% of Ni, 0.6% of Ti, 0.35% of Mn, 0.41% of Zr, 0.52% of Sc, 0.22% of Mo, 0.41% of Nb, 4.3% of Mg, 0.9% of Al, 0.05% of P, 0.04% of S, 0.33% of V, 1.45% of B, and the balance of Fe and other unavoidable impurity elements.

The second technical purpose of the invention is realized by the following technical scheme: a preparation method of an ultra-low carbon high temperature resistant welding wire specifically comprises the following steps:

Step 1, ingredient smelting: weighing the components according to the proportion, and then adding the components into a heating furnace for smelting;

Step 2, refining: after all the components in the heating furnace are completely melted, adding a refining agent, and uniformly stirring, wherein the refining agent accounts for 0.3-0.5% of the total mass of the alloy liquid;

step 3, casting: and (3) standing for 10-30 min after refining, removing molten slag on the surface of the alloy liquid, and casting into ingots:

Step 4, preparing a wire blank: heating the cast ingot, and performing hot extrusion to obtain a line blank;

Step 5, drawing: drawing the wire blank prepared in the step 4 through a wire drawing machine, then performing intermediate annealing, and continuing to draw the wire blank to a certain specification;

Step 6, welding wire surface treatment: and carrying out acid washing, polishing and passivation treatment on the surface of the welding wire to obtain the finished welding wire.

By adopting the technical scheme, the molten alloy is refined after the raw materials are melted, and the refining aims to remove impurities in the alloy, eliminate or reduce oxide inclusions and gas as much as possible and improve the purification degree of metal. The refined alloy liquid is cast and drawn to form a welding wire with a certain specification, the wire blank is subjected to work hardening in the drawing process to cause plasticity reduction, and the phenomenon that the wire blank is broken easily occurs, so that intermediate annealing is needed in the drawing process to recover the plasticity of the wire blank, the dislocation density in the wire blank is reduced in the annealing process, the residual stress is partially released, and the wire blank is softened, so that the drawing can be continuously carried out, and the possibility of breaking the wire blank is reduced. The surface of the drawn welding wire has greasy dirt impurities such as lubricating oil and the like, a layer of black ash is easily formed on the surface of stainless steel in the welding process, and the purpose of acid washing is to remove the greasy dirt on the surface of the welding wire. The polishing can reduce the roughness of the surface of the welding wire, a uniform and compact passive film is formed on the surface of the welding wire, the corrosion resistance of the welding wire is improved, and in addition, the polished welding wire can enable the welding wire to be stable in a wire feeding process, so that the stability of the welding process is ensured.

The invention is further provided with: the smelting temperature in the step 1 is 1850-1950 ℃.

By adopting the technical scheme, the temperature of 1850-1950 ℃ can ensure that all the added components can be melted to form uniform alloy liquid.

the invention is further provided with: the refining temperature in the step 2 is 1600-1700 ℃.

By adopting the technical scheme, the refining effect is good at 1600-1700 ℃.

The invention is further provided with: the acid washing solution in the step 6 is a sulfuric acid solution with the mass fraction of 15-20%, the acid washing temperature is 30-50 ℃, and the acid washing time is 2-5 min.

through adopting above-mentioned technical scheme, the pickling temperature is high is favorable to improving the pickling effect, but too high pickling temperature leads to acid mist to form easily, influences operating environment, brings certain harm for operating personnel's health.

In conclusion, the beneficial technical effects of the invention are as follows:

1. The ultra-low carbon content can reduce and avoid chromium compounds formed at the welding seam, thereby reducing the intergranular corrosion of the stainless steel, improving the strength of the stainless steel and prolonging the service life of the stainless steel. The addition of Si can lower the melting point of the alloy and reduce the linear expansion coefficient, so that the alloy is not easy to generate crystal cracks and has good weldability and castability after being melted. Si is a deoxidizing element, and can prevent iron from being combined with oxygen, and FeO can be reduced in a heating furnace. Ti, Zr, Sc, V and B are beneficial to improving the performance of the welding seam, refining crystal grains of crack metal, reducing the tendency of generating welding cracks during welding and improving the ductility and toughness of the welding seam. The addition of a small amount of Ti can ensure that the alloy steel can precipitate a primary TiAl3 phase from a melt in the solidification process, the particles are very close to an alpha (Al) matrix in the lattice structure and size, are good substrates on which Al atoms are accumulated, and can provide cores for the heterogeneous nucleation of the alpha (Al) matrix, thereby refining the weld grain structure.

Mn plays roles of microalloying and strengthening and toughening, and can also improve the stress corrosion resistance of the alloy steel, and the addition of Mn can ensure that Mg phase is uniformly precipitated, so that the corrosion sensitivity of the alloy steel is reduced, and particularly, the stress corrosion cracking resistance is obviously improved, thereby improving the mechanical property of a welding line. Mo in the alloy steel can improve the strength and hardness of the steel, refine crystal grains, prevent temper brittleness and overheating tendency, improve the plasticity of the alloy steel, reduce the tendency of generating cracks and improve impact toughness;

3. The Sc is high in cost, in order to reduce the Sc content, Zr is added to form dispersed Al ₃ (Sc.Zr) particles, and the Zr and the Sc in the alloy generate strong strengthening effects such as fine grain strengthening, substructure strengthening, dispersion strengthening, coherent strengthening and the like on the alloy;

4. After Mg is added, Mg and Si atoms are gathered on a crystal face of a substrate to form a solute atom enrichment area, the Mg and Si atoms are further enriched and tend to be ordered along with the increase of aging temperature and the extension of time, the atoms rapidly grow into a needle shape or a rod shape, the Mg and the Si can form a beta (Mg ₂ Si) strengthening phase to improve the tensile strength of the welding wire, and meanwhile, the addition of the Mg can also enable the surface of the prepared welding wire to be smooth and clean, the deformation resistance of the alloy in the preparation process of the welding wire is increased along with the increase of the Mg content, the Mg content is high, the forming processing of the welding wire is not facilitated, and therefore the Mg content is 3.0-.

drawings

FIG. 1 is a flow chart of the preparation method of the ultra-low carbon high temperature resistant welding wire of the invention.

Detailed Description

The present invention will be described in further detail with reference to examples.