CN115805389A - Gas protection solid welding wire suitable for being matched with sulfuric acid dew point corrosion resistant pipeline - Google Patents
Gas protection solid welding wire suitable for being matched with sulfuric acid dew point corrosion resistant pipeline Download PDFInfo
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- CN115805389A CN115805389A CN202211663009.1A CN202211663009A CN115805389A CN 115805389 A CN115805389 A CN 115805389A CN 202211663009 A CN202211663009 A CN 202211663009A CN 115805389 A CN115805389 A CN 115805389A
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Abstract
The invention provides a gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline, which comprises the following chemical components in percentage by weight: 0.07 to 0.09 weight percent of C, 1.20 to 1.60 weight percent of Mn, 0.26 to 0.38 weight percent of Si, 0.90 to 1.00 weight percent of Cr, less than or equal to 0.025 weight percent of S, less than or equal to 0.025 weight percent of P, 0.07 to 0.09 weight percent of Sb, 0.25 to 0.35 weight percent of Cu, and the balance of Fe and inevitable impurities, wherein the sum of the mass fractions of the components is 100 percent. The welding wire provided by the invention has the advantages that the chemical components are scientifically proportioned, the welding performance is stable, and the obtained cladding metal has comprehensive mechanical properties, acid resistance, high temperature resistance and the like.
Description
Technical Field
The invention belongs to the field of welding wire processing, and particularly relates to a gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline.
Background
In the industrial fields of metallurgy, electric power, petrochemical industry and the like, flue gas treatment systems using heavy oil or coal as main industrial fuel, such as air preheaters, heat exchangers, economizers, flues, chimneys, desulphurization devices and the like at low-temperature parts of boilers, generally encounter the situation that the sulfur content in the fuel is higher, and SO is generated after combustion 2 Wherein a part of the water is regenerated to SO 3 。SO 2 Combined with water vapor to form H when the dew point temperature is reached 2 SO 4 The phenomenon of corrosion of the equipment caused by the dilution to the concentrationReferred to as "sulfuric acid dew point corrosion". Different from the common atmospheric corrosion phenomenon, the corrosion inhibitor not only corrodes common carbon steel, but also can corrode stainless steel and the like, and has great harm to industrial production devices.
In order to solve the problem of sulfuric acid corrosion of equipment, technicians propose various methods, such as fuel or flue gas desulfurization, heating surface wall temperature increase, use of sulfuric acid corrosion resistant materials, and the like, but all have advantages and disadvantages. After long-term continuous experimental research and production practice, the sulfuric acid corrosion resistant material has the best effect from the viewpoints of cost control, process simplification, energy conservation and the like. The sulfuric acid dew point corrosion resistant steel has the characteristics of low cost, excellent acid resistance and the like, is widely applied to coal economizers, flues and waste gas desulfurization equipment, and achieves good practical effect. At present, welding materials matched with the sulfuric acid dew point corrosion resistant steel are conventional welding materials, and the welding seam does not have the characteristics of acid resistance and the like, so that the phenomenon of corrosion at the welding seam is easy to occur, and the service life of an industrial production device is greatly reduced. Therefore, the development of a welding material suitable for the pipeline with sulfuric acid dew point corrosion resistance is needed.
Compared with an electric welding rod and a flux-cored wire, the gas shielded solid wire has the advantages of good operation process performance, attractive weld forming, easy operation of welders and the like, and meanwhile, the preparation process of the gas shielded solid wire is relatively simple.
Due to the harsh service environment, the sulfuric acid corrosion resistant welding material requires acid resistance, and meanwhile, the weld metal needs to meet the requirements of heat resistance, high temperature resistance and the like. In addition, in order to reduce the dead weight and bear high pressure, low-alloy high-strength steel is generally adopted, so the design of welding materials also meets the requirements of low alloy high strength and high toughness.
Disclosure of Invention
In view of this, the invention aims to provide a gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline comprises the following chemical components in percentage by weight: 0.07-0.09wt% of C, 1.20-1.60wt% of Mn1.26-0.38 wt% of Si, 0.90-1.00wt% of Cr, less than or equal to 0.025wt% of S, less than or equal to 0.025wt% of P, 0.07-0.09wt% of Sb, 0.25-0.35wt% of Cu, and the balance of Fe and inevitable impurities, wherein the sum of the mass fractions of the components is 100%.
Further, the mass percent of S is less than or equal to 0.008wt%.
Further, the mass percent of P is less than or equal to 0.015wt%.
Further, the mass percent of Mn is 1.20-1.30wt%.
Further, the mass percent of Cu is 0.25-0.30wt%.
Further, the mechanical properties of the welding wire cladding metal are as follows: the yield strength Rp0.2 is more than or equal to 490MPa; the tensile strength Rm is more than or equal to 620MPa; the elongation A after fracture is more than or equal to 19 percent, and the low-temperature impact toughness is as follows: the impact energy of the welding seam reaches more than 47J at the temperature of minus 20 ℃.
The welding method of the gas protection solid welding wire suitable for being matched with the sulfuric acid dew point corrosion resistant pipeline is characterized by comprising the following steps of: the method comprises the following steps: the composition by volume percentage is Ar 70-90%, CO 2 Welding 10-30% of Ar-rich mixed gas, wherein the welding parameters are as follows: welding speed: 4-8mm/s, gas flow, 15-25L/min, current: 260-300A, voltage: 27-32V, and the temperature is 150-180 ℃.
Further, the Ar-rich mixed gas comprises 80-90% by volume of Ar and CO 2 10-20％。
Carbon element (C): carbon is an essential element in low alloy wire steel, and its presence increases the strength of the weld, but too high a carbon content affects the weldability of the steel, so the carbon content in the steel should be controlled within a suitable range. An increase in the carbon content reduces the corrosion resistance of the weld joint, high carbon steel in open air is particularly susceptible to corrosion and rust, and an increase in the carbon content correspondingly increases the cold brittleness and the aging sensitivity of the weld joint. Research shows that the corrosion resistance of the low-carbon copper-containing steel is the best.
Manganese element (Mn): manganese is a basic component element in low-alloy welding wire steel, can properly improve the strength of a welding seam and improve the processing performance, but the manganese element has adverse effect on the corrosion resistance of the steel. Therefore, the manganese element must comprehensively consider the dual functions of corrosion resistance and nitrogen fixation.
Elemental silicon (Si): silicon is also an essential element in low alloy wire steel, and when silicon and copper coexist, the corrosion resistance of the weld can be improved appropriately, but too high a silicon content in the wire steel deteriorates the workability of the steel.
Chromium element (Cr): the addition of chromium element can not only improve the heat intensity performance and high-temperature oxidation resistance of the welding line, but also improve the corrosion resistance of the welding line. The chromium has lower potential and has a tendency of passivation, thereby playing a role in improving the corrosion resistance, and the corrosion resistance effect of the chromium is more obvious under the coordination of copper. The chromium element can be combined with the carbon element in the molten pool, so the corrosion resistance of the chromium can be reduced along with the increase of the carbon element, and the corrosion resistance of the chromium element can be better exerted only by reasonably controlling the content ratio of the carbon element to the chromium element in the welding wire.
Antimony element (Sb): the addition of antimony element has great help to improve the sulfuric acid corrosion resistance and the wear resistance of the welding line, antimony can inhibit the anodic reaction, and simultaneously Cu is formed on the surface of the welding line 2 The Sb thin film can also suppress the cathode reaction. However, higher antimony content reduces weld strength and increases brittleness.
Copper element (Cu): the copper element plays a role in strengthening ferrite in the welding seam and plays an important role in improving the corrosion resistance of the welding seam. The copper plays a role of an active cathode in the corrosion process of the welding seam, and can promote the welding seam to generate anodic passivation under certain conditions, so that the corrosion speed of the welding seam is reduced; meanwhile, copper is easy to combine with sulfur in steel, and Cu is formed on the surface of a welding seam 2 And the S passivates the film, so that the anode reaction and the cathode electrochemical reaction are inhibited, and the sulfuric acid dew point corrosion is relieved. When the content of the copper element exceeds 0.50 percent, the plasticity of the welding line can be greatly reduced, and the hot working performance of the welding line is influenced.
Phosphorus (P): even if the content of phosphorus is low, cracks can be nucleated on MnS, but the size is small and cannot be detected. However, if the phosphorus content is high, cracks can be nucleated and propagated in oxide inclusions and grain boundaries even if S is low (S = 0.001%). Meanwhile, P also belongs to easily segregated elements, so that cold brittleness of the welding line is caused, grain boundary segregation of other harmful residual elements is promoted, and the quality of the welding line is further deteriorated, therefore, the lower the P in the welding wire is, the better the P is.
Sulfur (S): for resistance to sulfuric acid dew point corrosion, the presence of sulfur in an amount that promotes Cu formation on the weld surface 2 And S passivates the film, thereby suppressing an anode reaction and an electrochemical reaction of the cathode. However, when S, cu and Sb are simultaneously present in steel, a low-melting-point coexisting body is easily generated at a grain boundary, the comprehensive performance of a weld joint is seriously damaged, and a corrosion source point of sulfide inclusion is formed, so that the S content needs to be strictly controlled.
Compared with the prior art, the invention has the following advantages:
the gas protection solid welding wire suitable for being matched with the sulfuric acid dew point corrosion resistant pipeline has the following advantages:
compared with the traditional welding wire, the solid welding wire for gas protection matched with the sulfuric acid dew point corrosion-resistant pipeline has the characteristics of acid resistance and high temperature resistance, and has high strength and high toughness. The welding wire improves the corrosion resistance of the welding line by adding a proper amount of elements such as Cr, cu, sb and the like; by controlling proper Mn, si, P, S and other elements, the good mechanical property of the welding seam is ensured.
Detailed Description
Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.
The present invention will be described in detail with reference to examples.
Example 1
A gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline comprises the following chemical components in percentage by weight: 0.078wt.% of C, 1.25wt.% of Mn, 0.30wt.% of Si, 0.91wt.% of Cr, 0.008wt.% of S, 0.015wt.% of P, 0.075wt.% of Sb, 0.26wt.% of Cu, the total amount of unavoidable impurity elements being less than or equal to 0.30wt.%, and the balance being Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 545MPa; tensile strength R m Is 652MPa; elongation after break A was 19.5%; the low-temperature impact toughness is as follows: the weld joint impact energy at minus 20 ℃ is 58.3J; the sample is immersed in 50% sulfuric acid solution at 70 +/-2 deg.C for 24 hr to obtain a corrosion soaking test, and the average corrosion rate of the sample is 34.81g/m 2 .h。
Example 2
A gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline comprises the following chemical components in percentage by weight: 0.082wt.%, 1.21wt.% Mn, 0.35wt.% Si, 0.95wt.% Cr, 0.007wt.% S, 0.015wt.% P, 0.078wt.% Sb, 0.28wt.% Cu, the sum of impurity elements is less than or equal to 0.30wt.% and the balance Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 Is 532MPa; tensile strength R m Is 676MPa; the elongation A after fracture is 19.0%; the low-temperature impact toughness is as follows: the weld joint impact energy at the temperature of minus 20 ℃ is 52.6J; the sample is immersed in 50% sulfuric acid solution at 70 +/-2 deg.c for 24 hr to obtain corrosion soaking test with average corrosion rate of 34.23g/m 2 .h。
Example 3
A gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline comprises the following chemical components in percentage by weight: 0.071wt.% of C, 1.21wt.% of Mn, 0.32wt.% of Si, 0.94wt.% of Cr, 0.006wt.% of S, 0.014wt.% of P, 0.078wt.% of Sb, 0.25wt.% of Cu, the sum of impurity elements not exceeding 0.30wt.% being unavoidable, and the balance being Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 Is 508MPa; tensile strength R m Is 625MPa; elongation after break A is 21.0%; the low-temperature impact toughness is as follows: the weld joint impact energy at the temperature of minus 20 ℃ is 72J; the sample was immersed at a temperature of (70 + -)2) The corrosion immersion test was carried out in a 50% sulfuric acid solution at 50 ℃ for 24 hours, and the average corrosion rate of the test piece was 33.12g/m 2 .h。
Example 4
A gas protection solid welding wire suitable for being matched with a sulfuric acid dew point corrosion resistant pipeline comprises the following chemical components in percentage by weight: 0.082wt.% of C, 1.30wt.% of Mn, 0.32wt.% of Si, 0.92wt.% of Cr, 0.008wt.% of S, 0.014wt.% of P, 0.081wt.% of Sb, 0.25wt.% of Cu, the total amount of impurity elements is not more than 0.30wt.%, and the balance of Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 523MPa; tensile strength R m Is 686MPa; the elongation A after fracture is 19.0%; the low-temperature impact toughness is as follows: the impact work of the welding seam at the temperature of minus 20 ℃ is 61.5J; the sample is immersed in 50% sulfuric acid solution at 70 +/-2 deg.C for 24 hr to obtain a corrosion soaking test, and the average corrosion rate of the sample is 32.51g/m 2 .h。
Comparative example 1
A gas shielded welding wire comprises the following chemical components in percentage by weight: 0.067wt.% of C, 1.55wt.% of Mn, 0.78wt.% of Si, 0.08wt.% of Ti, 0.015wt.% of S, 0.018wt.% of P, 0.10wt.% of Cu, the total amount of unavoidable impurity elements is less than or equal to 0.30wt.%, and the balance of Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 Is 531MPa; tensile strength R m Is 620MPa; the elongation A after fracture is 20 percent; the low-temperature impact toughness is as follows: the weld joint impact energy at minus 20 ℃ is 76.5J; the sample is immersed in 50 percent sulfuric acid solution at the temperature of 70 +/-2 ℃ for 24 hours of corrosion immersion test, and the average corrosion rate of the sample is 412.23g/m 2 .h。
Comparative example 2
A gas shielded welding wire comprises the following chemical components in percentage by weight: 0.074wt.% of C, 1.67wt.% of Mn, 0.60wt.% of Si, 0.30wt.% of Mo, 0.012wt.% of S, 0.014wt.% of P, 0.07wt.% of Ti, 0.10wt.% of Cu, the sum of impurity elements is not more than 0.30wt.% and the balance of Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 Is 512MPa; tensile strength R m 623MPa; the elongation A after fracture is 23.0 percent; the low-temperature impact toughness is as follows: the weld joint impact energy at minus 20 ℃ is 85J; immersing the sample in 50% sulfuric acid solution at 70 + -2 deg.C for 24 hr to obtain average corrosion rate of 389.12g/m 2 .h。
Comparative example 3
A gas shielded welding wire comprises the following chemical components in percentage by weight: 0.062wt.%, 1.45wt.% Mn, 0.87wt.% Si, 0.12wt.% Ti, 0.006wt.% S, 0.015wt.% P, 0.0028wt.% B, 0.10wt.% Cu, the total of impurity elements is less than or equal to 0.30wt.% and the balance Fe; the sum of the mass percentages of the components is 100 percent.
The obtained welding wire is subjected to deposited metal performance experiment: yield strength R p0.2 Is 545MPa; tensile strength R m Is 640MPa; elongation after break A is 22.0%; the low-temperature impact toughness is as follows: the weld joint impact energy at the temperature of minus 20 ℃ is 86.3J; the sample is immersed in 50 percent sulfuric acid solution at the temperature of 70 +/-2 ℃ for 24 hours of corrosion immersion test, and the average corrosion rate of the sample is 324.55g/m 2 .h。
In the above embodiments and comparative examples, the welding wire is welded by using an Ar-rich mixed gas containing, by volume, 80% of Ar and 20% of CO2 to obtain a deposited metal, where the welding parameters are: welding speed: 7mm/s; gas flow rate: 22L/min; current: 280A, voltage: about 30V and 140 ℃ per road temperature.
A summary of the chemical composition of the welding wire of the examples of the invention and the comparative examples is shown in Table 1.
TABLE 1 chemical composition
The properties of the wire clad metals of the examples of the present invention and the comparative examples are summarized in table 2.
TABLE 2 cladding Metal Properties
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (8)
1. The utility model provides a supporting gas shielded solid welding wire that uses suitable for sulphuric acid dew point corrosion resistant pipeline which characterized in that: the solid welding wire comprises the following chemical components in percentage by weight: 0.07 to 0.09 weight percent of C, 1.20 to 1.60 weight percent of Mn, 0.26 to 0.38 weight percent of Si, 0.90 to 1.00 weight percent of Cr, less than or equal to 0.025 weight percent of S, less than or equal to 0.025 weight percent of P, 0.07 to 0.09 weight percent of Sb, 0.25 to 0.35 weight percent of Cu, and the balance of Fe and inevitable impurities, wherein the sum of the mass fractions of the components is 100 percent.
2. The gas-shielded solid welding wire suitable for the sulfuric acid dew point corrosion-resistant pipeline as claimed in claim 1, wherein: the mass percent of S is less than or equal to 0.008wt%.
3. The gas protection solid welding wire suitable for the pipeline with the resistance to the sulfuric acid dew point corrosion as claimed in claim 1, wherein: the mass percentage of P is less than or equal to 0.015wt%.
4. The gas protection solid welding wire suitable for the pipeline with the resistance to the sulfuric acid dew point corrosion as claimed in claim 1, wherein: the mass percent of Mn is 1.20-1.30wt%.
5. The gas-shielded solid welding wire suitable for the sulfuric acid dew point corrosion-resistant pipeline as claimed in claim 1, wherein: the mass percent of the Cu is 0.25-0.30wt%.
6. The gas protection solid welding wire suitable for the pipeline with the resistance to the sulfuric acid dew point corrosion as claimed in claim 1, wherein: the mechanical properties of the welding wire cladding metal are as follows: the yield strength Rp0.2 is more than or equal to 490MPa; the tensile strength Rm is more than or equal to 620MPa; the elongation A after fracture is more than or equal to 19 percent, and the low-temperature impact toughness is as follows: the impact energy of the welding seam reaches more than 47J at the temperature of minus 20 ℃.
7. A welding method using the gas shielded solid welding wire suitable for the sulfuric acid dew point corrosion-resistant pipeline as set forth in any one of claims 1 to 6, characterized in that: the method comprises the following steps: the composition by volume percentage is Ar 70-90%, CO 2 Welding 10-30% of Ar-rich mixed gas, wherein the welding parameters are as follows: welding speed: 4-8mm/s, gas flow, 15-25L/min, current: 260-300A, voltage: 27-32V, and the temperature is 150-180 ℃.
8. The welding method of the gas protection solid welding wire suitable for the sulfuric acid dew point corrosion resistant pipeline, which is used together with the pipeline, according to claim 7, is characterized in that: the Ar-rich mixed gas comprises 80-90% of Ar and CO in percentage by volume 2 10-20％。
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| CN202211663009.1A CN115805389A (en) | 2022-12-23 | 2022-12-23 | Gas protection solid welding wire suitable for being matched with sulfuric acid dew point corrosion resistant pipeline |
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| CN202211663009.1A CN115805389A (en) | 2022-12-23 | 2022-12-23 | Gas protection solid welding wire suitable for being matched with sulfuric acid dew point corrosion resistant pipeline |
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