CN112846566B

CN112846566B - Solid solution strengthening type heat-resistant alloy C-HRA-2 argon arc welding wire

Info

Publication number: CN112846566B
Application number: CN202011638415.3A
Authority: CN
Inventors: 陈正宗; 刘正东; 梁宝琦; 包汉生; 何西扣; 王立民; 杨钢
Original assignee: Central Iron and Steel Research Institute
Current assignee: Central Iron and Steel Research Institute
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-03-29
Anticipated expiration: 2040-12-31
Also published as: CN112846566A

Abstract

A solid solution strengthening type welding wire for C-HRA-2 argon arc welding of heat-resistant alloy belongs to the technical field of heat-resistant alloy welding materials. The welding wire comprises the following components in percentage by weight: 0.06-0.12% of C; si is less than 1.0 percent; mn is less than 1.0 percent; p is less than or equal to 0.015 percent; s is less than or equal to 0.001 percent; 20-22% of Cr; 10-13% of Co; 8.1 to 8.8 percent of Mo; 0.1 to 1.0 percent of W; n is less than or equal to 0.0025 percent; o is less than or equal to 0.0025 percent; the balance being Ni and unavoidable impurity elements. The welding process has the advantages that the hot crack resistance sensitivity is improved by 90%, the welding strain aging cracks of the alloy are eliminated fundamentally, the alloy has excellent physical and mechanical properties and excellent impact toughness matched with the base metal, the welding process performance is excellent, the metal fluidity of a welding line is good, the formability of the welding line is good, and the production cost is 10-15% lower than that of the conventional ERNiCrCoMo-1 welding wire.

Description

Solid solution strengthening type heat-resistant alloy C-HRA-2 argon arc welding wire

Technical Field

The invention belongs to the technical field of welding materials, and particularly provides a solid solution strengthening type welding wire for C-HRA-2 argon arc welding of a heat-resistant alloy, which is suitable for bottoming or filling of manual argon arc welding/semi-automatic argon arc welding or narrow-gap hot wire TIG welding of a novel heat-resistant alloy C-HRA-2.

Background

The improvement of steam parameters (temperature and pressure) of the thermal power generating unit is the most important way for improving the thermal efficiency of coal-fired power generation and realizing coal saving and emission reduction. However, the biggest "bottleneck" problem that restricts the development of thermal power generating units to higher parameters is the higher grade heat-resistant material and its engineering welding. The 630 ℃ ultra-supercritical coal-fired power plant in great Tangshan is the first thermal power unit with the highest steam parameter in the world, the power plant is fully started before 2020, and the heat-resistant materials selected in the highest temperature sections of a boiler header, a main steam pipeline and the like are the only optional engineering in the world at present

A martensitic heat-resistant steel. G115 steel is independently researched by the inventor group for more than ten yearsA novel martensite heat-resistant steel (patent number: ZL 201210574445.1) capable of being used for 630-grade 650-DEG C steam parameters is developed and developed by a material research and development unit, a steel mill, a pipe plant, a boiler plant, a steam turbine plant, an electric construction company, a pipe plant, a welding material plant and other electric station construction whole chain unit to jointly participate and cooperatively attack and solve the engineering welding problem of restricting the final difficult problem of G115 steel engineering application, namely a large-caliber thick-wall pipe (the maximum wall thickness of engineering application is 120mm) in 6 months in 2020, and the G115 boiler pipe batch and stable engineering supply is provided in China at present. Through the research on the application of the G115 steel engineering by the lead organization, numerous failures are experienced during the period, and valuable engineering experience and teaching are accumulated, so that the following can be realized: in order to obtain engineering application, a new material which is independently researched and developed must solve the engineering welding problem, including the development of matched welding materials.

Solid solution strengthened heat-resistant alloy

(patent No.: ZL 201510813308.2) is in heat-resistant alloy

(patent No. ZL 201410095587.9) by completely removing gamma' phase (Ni)₃(Al, Ti)) to form elements Al and Ti, regulating and controlling the maximum solid solution strength limit of a matrix, and the independently developed pure solid solution strengthening type nickel-based heat-resisting alloy initially has market admittance evaluation conditions. In order to lead the development of world thermal power technology, further reduce coal consumption and improve heat efficiency, several power groups in China actively demonstrate 650-. China successfully constructs an autonomous controllable 630-700 ℃ ultra-supercritical coal-fired boiler material system in which pure solid solution strengthening type nickel-based heat-resistant alloy

And

is one of the candidate materials of the relevant pipelines of the ultra-supercritical coal-fired power plant boiler at 650 ℃ and 700 ℃ in the futureAnd the industrial manufacture of boiler pipes of basically all dimensions of novel heat-resistant materials required by the construction of power station boilers is completed, and a solid material foundation is provided for the material selection of the ultra-supercritical power station boiler with the temperature of 650 ℃ in China. (Liu Zhengdong, Cheng Zheng Zong et al. 630 ℃. 700 ℃ ultra-supercritical coal-fired power station heat-resistant pipe and manufacturing technology development thereof [ J]The journal of metals 2020,56(4): 539-.

In the process of building a power station and installing a boiler, the pipelines are connected by welding, so that the performance of a welding joint is directly related to whether the power station can run safely and reliably. The nickel-based alloy has a complex component system, more types of added elements are added in a matrix, and compared with ferrite system or austenite system heat-resistant steel, the nickel-based alloy has higher welding crack sensitivity and is easy to generate welding cracks. The research shows that: the general nickel-based alloy is easy to generate hot cracks and reheat cracks, and is divided into four types: crystal cracks, liquefaction cracks, plastic loss cracks, and strain age cracks. The thermal cracks are divided into crystal cracks and liquefied cracks, and the reheat cracks are mainly strain age cracks. The mechanism of formation of the liquation cracks and the crystal cracks is the same, and the liquation cracks and the crystal cracks are cracked under the action of higher stress in the welding thermal cycle due to the existence of weak low-melting phases or eutectic crystals among the crystals. The difference between the two is that the crystal cracks are formed in the process of solidifying the liquid weld metal, and the liquefied cracks are formed by remelting the intercrystalline layer of the solid base metal under the action of the peak temperature of the thermal cycle. Strain age cracking generally occurs when aging is applied after welding or when the alloy is used at high temperatures after welding. When Al and Ti are contained in the Ni-based alloy matrix, the matrix is internally provided with a gamma' phase (Ni)₃(Al, Ti)) is strengthened, and the grain boundary strength is generally lower than the intergranular strength in a high temperature environment, which weakens the grain boundary, easily causes plastic deformation of the grain boundary, increases the strain age cracking tendency, and when the actual deformation amount of the grain boundary exceeds its plastic deformation capability, strain age cracking occurs, and thus, the strain age cracking is closely related to the precipitation rate and the amount of the precipitated phase. (State of the Art for welding cracks in Caui Nickel-based alloys [ J ]].DOI 10.11900/0412.1961.2020.00200)

European in 1998The method comprises the steps of conducting material selection research on 700 ℃ ultra-supercritical power stations, establishing a 700 ℃ test platform in a Germany E.ON Scholven power plant, and examining an Inconel 617 modified alloy (Inconel 617B, also called CCA 617) large-caliber thick-wall pipeline for nearly two years through the platform to find that annular cracks appear in a welding heat affected zone. Research shows that the annular cracks appear at the welded joints and propagate along the crystal, and are local over-high residual stress caused by the aggregation of precipitates (mainly gamma' -phase) in the service period, and belong to strain age cracks, also called stress relaxation cracks. Inconel 617 alloy (UNS N06617) and its improved alloy common welding materials are special matched welding wires (AWS A5.14: ERNiCrCoMo-1, ISO 18274SNi6117 and GB/T15620: SNi6117) and welding rods (AWS A5.11: ENiCrCoMo-1, ISO 14172ENi6117 and GB/T13814: ENi 6117); the ENiCrCoMo-1 welding rod core comprises the following components in percentage by mass: 0.05 to 0.15 percent of C; si is less than or equal to 1.0 percent; mn is less than or equal to 3.0 percent; s is less than or equal to 0.015 percent; p is less than or equal to 0.020%; 20.0 to 26.0 percent of Cr; 9.0 to 15.0 percent of Co; 8.0 to 10.0 percent of Mo; nb is less than or equal to 1.0 percent; al is less than or equal to 1.5 percent; ti is less than or equal to 0.6 percent; cu is less than or equal to 0.5 percent; fe is less than or equal to 5.0 percent; ni is more than or equal to 45.0 percent; the ERNiCrCoMo-1 welding wire comprises the following components in percentage by mass: 0.05 to 0.15 percent of C; si is less than or equal to 1.0 percent; mn is less than or equal to 1.0 percent; s is less than or equal to 0.015 percent; p is less than or equal to 0.03 percent; 20.0 to 24.0 percent of Cr; 10.0 to 15.0 percent of Co; 8.0 to 10.0 percent of Mo; 0.8 to 1.5 percent of Al; ti is less than or equal to 0.6 percent; cu is less than or equal to 0.50 percent; fe is less than or equal to 3.0 percent; the balance being Ni. As can be seen, the Inconel 617(UNS N06617) special matching electrode and welding wire both contain a gamma' phase (Ni)₃(Al, Ti)) form elements Al and Ti, and welded joints are prone to strain age cracking during high temperature, high pressure, long service life of utility boilers. In order to improve the strain aging cracks of Inconel 617 and the improved alloy welded joint thereof, the strain aging cracks can be relieved by post-welding stress relief annealing heat treatment (980 ℃/3h/AC), but are difficult to be eliminated fundamentally (see the documents of van Wortel and the like), so if ENiCrCoMo-1 and ER NiCrCoMo-1 welding materials are adopted to weld a pure solid solution strengthening type heat-resistant alloy C-HRA-2 steel pipe, the construction cost and time of a power station are greatly increased, the strain aging cracks of the welded joint are difficult to be eliminated fundamentally, and from the aspect of engineering application, a special matched welding material needs to be developed aiming at the physical metallurgy characteristics of a pure solid solution strengthening type novel heat-resistant alloy C-HRA-2.

The patent CN 109848609A "a low expansibility nickel-based welding wire", the welding wire is prepared from the following components by weight percent: fe is less than or equal to 1.5 percent; 14-18% of Cr; 1.4 to 1.5 percent of Al; 1.4 to 1.5 percent of Ti; 1.5 to 2.5 percent of Mo; 0.5 to 1 percent of W; si is less than or equal to 0.05 percent; mn is less than or equal to 0.5 percent; cu is less than or equal to 0.1 percent; c is less than or equal to 0.05 percent; b is less than or equal to 0.004 percent; zr is less than or equal to 0.02 percent; the balance being Ni. The welding wire contains gamma' phase (Ni)₃(Al, Ti)) form elements Al and Ti, and the content is higher, so that the alloy is used for precipitation strengthening nickel-base superalloy welding.

The patent CN 108067763A "nickel-based welding wire", the welding wire composition is according to the mass percent: c0.02-0.09%; 18-22% of Cr; 7-11% of Mo; 11-14% of Co; ta 0.05-0.2%; 0.2 to 0.4 percent of Nb; 0.7-1.2% of Al; 1.5-2.5% of Ti; the balance of Ni and impurity elements; the welding wire contains gamma' phase (Ni)₃(Al, Ti)) form elements of Al and Ti, have high content and are used for welding and repairing steam turbine parts in a high-temperature service environment of 700 ℃.

The welding wire has the technical problems that the matching performance of the chemical components, the mechanical properties and the like of deposited metal and the pure solid solution strengthening type heat-resistant alloy C-HRA-2 of the base metal is poor and the like which cannot be overcome. The novel nickel-based heat-resistant alloy C-HRA-2 is one of candidate materials of a pipeline related to a 650 ℃ ultra-supercritical power station boiler, and the novel welding wire which is matched with the novel nickel-based heat-resistant alloy C-HRA-2, low in cost and high in crack resistance sensitivity is researched and developed, so that the industrial popularization and application of the C-HRA-2 heat-resistant alloy which is independently researched and developed in China are promoted, the national clean coal electric strategy layout is promoted, the world thermal power technology is led, and important strategic significance and engineering value are achieved. Therefore, the solid-core welding wire for solid solution strengthening type novel heat-resistant alloy C-HRA-2 argon arc welding is urgent.

Disclosure of Invention

The invention aims to provide a solid-core welding wire for solid solution strengthening type heat-resistant alloy C-HRA-2 argon arc welding. By considering the chemical components and the comprehensive performance of the heat-resistant alloy C-HRA-2, the welding practicability in engineering, the high-temperature service requirement of a joint and the like, a novel heat-resistant alloy C-HRA-2 argon arc welding solid-core welding wire is researched and developed, so that the welding deposited metal not only has chemical components close to the parent metal of a C-HRA-2 alloy pipeline, but also has excellent strength-toughness matching, high endurance strength and excellent crack sensitivity resistance matched with the parent metal, particularly has strain aging crack resistance, the service life of the C-HRA-2 alloy pipeline is prolonged, the safe and reliable operation of a unit is ensured, the electric arc is stable during welding, the fluidity of the weld metal is good, and the weld joint is formed well.

The invention improves the thermal crack resistance sensitivity by 90 percent by the comprehensive action of each element, particularly no Al and Ti elements and strictly controlling the content of O, N, S, P and five-harmful elements at the same time as a whole, thereby fundamentally eliminating the welding strain aging cracks of the alloy, and the weld deposit metal does not have large block of Mo-rich metal formed by micro segregation of Mo-rich element₆C phase; the deposited metal components of the welding seam not only have chemical components similar to those of the parent metal, but also have excellent physical and mechanical properties and excellent impact toughness matched with the parent metal, the welding process performance is excellent, the fluidity of the welding seam metal is good, the formability of the welding seam is good, and the production cost is 10-15% lower than that of the conventional ERNiCrCoMo-1 welding wire.

The welding wire comprises the following components in percentage by weight: 0.06-0.12% of C; si is less than or equal to 1.0 percent; mn is less than or equal to 1.0 percent; p is less than or equal to 0.015 percent; s is less than or equal to 0.001 percent; 20-22% of Cr; 10-13% of Co; 8.1 to 8.8 percent of Mo; 0.1 to 1.0 percent of W; n is less than or equal to 0.0025 percent; o is less than or equal to 0.0025 percent; fe is less than or equal to 0.1 percent; the balance being Ni and unavoidable impurity elements; the fine materials required by the production of the welding wires with the components are put into a vacuum induction furnace according to a conventional welding wire smelting process, a certain proportion and a certain sequence, and are smelted, die-cast, forged and made into a wire rod, and the wire rod is drawn to a required diameter, then subjected to surface treatment and coiled.

The welding performance of the invention is as follows: the sensitivity of thermal crack resistance is improved by 90 percent, the welding strain aging cracks of the alloy are eliminated fundamentally, and the room-temperature impact energy of a welding joint is more than or equal to 110J; tensile strength R at room temperature_mNot less than 720MPa, yield strength R_p0.2More than or equal to 460MPa, and the elongation is more than or equal to 35 percent.

The principle of the invention is as follows:

c: the higher the C content in the wire, the greater the tendency for porosity and cracking in the weld. At the same time, the large amount of CO formed in the liquid metal by carbon oxidation also increases spatter or forms pores in the weld. Therefore, the content of C in the welding wire is controlled to be 0.05-0.13%.

Cr: the function of the medicine is mainly divided into three aspects: firstly, the solution is dissolved in a matrix and plays a role in solid solution strengthening; secondly, Cr is easily formed₂O₃The oxide film improves the high-temperature oxidation resistance and corrosion resistance; thirdly, forming M₂₃C₆The carbide plays a role in precipitation strengthening. Although the high temperature corrosion resistance is advantageous to increase the Cr content, the endurance strength is lowered by excessively increasing the Cr content. Therefore, the Cr content in the welding wire is controlled to be 20-22 percent.

Co: the main effect is solid solution strengthening because Co element can lower the stacking fault energy of γ matrix. The stacking fault can be reduced, the probability of occurrence of the stacking fault is increased, so that the cross slip of the dislocation is more difficult, the deformation needs larger external force, the strength is improved, the stacking fault can be reduced, the creep rate is reduced, and the creep resistance is increased. In addition, in the polycrystalline alloy, Co can increase the solubility of Cr, Mo, W, and C in the γ matrix, and further enhance the solid solution strengthening effect of the deposited metal. Therefore, in the welding wire, the content of Co is controlled to be 10-13%.

Mo and W: they are all refractory elements, the difference between the atomic radius of the elements and Ni is larger, and the addition of the elements can improve the interatomic bonding force, the recrystallization temperature and the diffusion activation energy, thereby effectively improving the permanent strength of deposited metal. In addition, higher Mo tends to promote the formation of harmful phases, such as the μ phase, of TCP. When discussing the effects of the two elements, W and Mo, one usually pays attention to their common aspect, but careful comparative studies show that the effects of the two elements are not equivalent. W has lower thermal diffusion coefficient than Mo element and stronger solid solution strengthening effect. W tends to segregate in the dendrite trunk region during solidification, while Mo tends to segregate in the interdendritic region. Excessive Mo and W are added into deposited metal, so that the short-term solid solution strength is high, but harmful phases such as metal solid solution, mu phase and Laves are formed in a long-term mode, and the structure stability and the impact toughness after long-term aging are affected. Therefore, not only is it better to maximize the solid solution strength of the deposited metal matrix if the solid solution strengthening element is added alone, but also the solid solution of the Ni matrix must be considered, and C, Co and Cr elements must be consideredElement matching is carried out to achieve the purpose of optimal solid solution strength, and simultaneously micro segregation of deposited metal is avoided to form large Mo blocks₆C phase, as shown in figure 1, welding C-HRA-2 small-bore pipe (specification: phi 44.5 × 10mm) by using existing mature commercial ERNiCrCoMo-1 welding wire, and scanning, observing and testing to obtain large Mo blocks formed by Mo microsegregation in weld joint₆The C phase not only influences the high-temperature endurance strength of the welding seam, but also reduces the impact toughness of the welding seam. The method comprehensively considers the maximization of the solid solution strengthening effect of the matrix and avoids the micro segregation of Mo element in the welding seam, the content of the Mo element in the alloy is controlled to be 8.1-8.8%, and the content of the W element is controlled to be 0.1-1.0%.

N and O: the heat-resisting alloy used at high temperature has service temperature over equal strength temperature and grain boundary precipitated phase (M)₂₃C₆Carbides) are prone to early failure. B element is easy to be deviated to grain boundary and enter M₂₃C₆Partial C atoms are replaced in the carbide, so that the growth and coarsening of the carbide are delayed, and the stability of the structure is improved. B is easy to combine with N into BN in the process of molten pool metal solidification, if the content of N is too high, coarse BN particles can be formed, the B element used for strengthening grain boundaries is consumed while the toughness of the alloy is weakened, and the high-temperature durable strength of deposited metal is seriously damaged. The base material is considered to contain B element, the welding rod is also added with B element, and the B element is burnt and N is increased when the manual arc welding is carried out. Therefore, the content of N and the content of O in the welding wire are controlled to be less than or equal to 0.002 percent.

N, O, S, P and five-harmful elements in the welding core have larger influence on the lasting strength and the lasting plasticity, so that the influence is the lowest possible, and N is respectively controlled to be less than or equal to 0.002 percent; o is less than or equal to 0.002 percent; s is less than or equal to 0.001 percent; p is less than or equal to 0.015 percent; pb is less than or equal to 0.001 percent; sb is less than or equal to 0.001 percent; sn is less than or equal to 0.001 percent; bi is less than or equal to 0.0001 percent; as is less than or equal to 0.001 percent.

The invention has the advantages and beneficial effects that: because the invention passes the comprehensive action of each element, especially no Al and Ti element, and simultaneously strictly controls O, N, S, P and the content of five harmful elements, as a whole, the thermal crack resistance sensitivity is improved by 90 percent, thereby fundamentally eliminating the welding strain aging cracks of the alloy, micro segregation of Mo element-free weld deposit metal and massive Mo-rich M of the weld deposit metal₆C phase; the welding seam deposited metal components not only have chemical components similar to those of the parent metal, but also have excellent physical and mechanical properties and excellent impact toughness matched with the parent metal; the impact energy of the welded joint at room temperature is more than or equal to 110J; tensile strength R at room temperature_mNot less than 720MPa, yield strength R_p0.2More than or equal to 460MPa, and the elongation is more than or equal to 35 percent; deposited metal 675 deg.C/10⁵The hour endurance strength extrapolated value is higher than 100 MPa; the welding process has excellent performance, good metal fluidity of the welding seam, good welding seam formability and 10 to 15 percent lower production cost than the prior ERNiCrCoMo-1 welding wire.

Drawings

FIG. 1 shows that the existing mature commercial ERNiCrCoMo-1 welding wire is adopted to weld a C-HRA-2 small-caliber pipe (specification: phi 44.5 multiplied by 10mm) and Mo element micro-segregation exists in a welding seam to form a large Mo block₆Scanning observation of phase C.

Detailed Description

The present invention will be further described with reference to the following specific examples. In the following examples, wire rods are manufactured according to a conventional nickel-based alloy argon arc welding wire smelting process, and are drawn to diameters phi 1.6 and phi 2.4mm, and then are subjected to surface treatment and coil splitting to obtain finished welding wires.

Example 1:

the welding wire comprises the following chemical components in percentage by weight: 0.05 percent of C; 0.9 percent of Si; 0.9 percent of Mn; 0.015 percent of P; 0.001% of S; 22 percent of Cr; 14 percent of Co; 8.8 percent of Mo; 1.0 percent of W; 0.0018% of N; 0.0015 percent of O; the balance being Ni and unavoidable impurity elements. The welding wire of the embodiment adopts manual argon arc welding, and the specification of the C-HRA-2 alloy pipe is as follows: phi is 44.5 multiplied by 10mm, the back surface in the tube is protected by high-purity argon (more than or equal to 99.99 percent), the gas flow is 10L/min, and the welding gun protects the gas flow to be 8L/min; specification of welding wire: phi 2.4mm, and the welding parameters are as follows: the welding current is 130A, the arc voltage is 13V, the preheating temperature is 100 ℃, and the interlayer temperature is 100 ℃; and carrying out heat treatment after no welding. The welding joint is qualified by 100% of ray inspection, and the mechanical properties of the welding seam metal are as follows: impact work at room temperature 115J; the tensile strength is 780MPa and the yield strength is 465MPa at room temperature.

Example 2:

the welding wire comprises the following chemical components in percentage by weight: 0.10 percent of C; 0.3 percent of Si; 0.6 percent of Mn; p is 0.010 percent; 0.001% of S; 20 percent of Cr; 10 percent of Co; 8.1 percent of Mo; 0.5 percent of W; 0.0015% of N; 0.002% of O; the balance being Ni and unavoidable impurity elements. The welding wire of the embodiment adopts manual argon arc welding, and the specification of the C-HRA-2 alloy pipe is as follows: phi is 44.5 multiplied by 10mm, the back surface in the tube is protected by high-purity argon (more than or equal to 99.99 percent), the gas flow is 10L/min, and the welding gun protects the gas flow is 9L/min; specification of welding wire: phi 2.4mm, and the welding parameters are as follows: the welding current is 110A, the arc voltage is 14V, the preheating temperature is 100 ℃, and the interlayer temperature is 100 ℃; and carrying out heat treatment after no welding. The welding joint is qualified by 100% of ray inspection, and the mechanical properties of the welding seam metal are as follows: the impact energy at room temperature is 125J; the tensile strength at room temperature is 775MPa, and the yield strength is 465 MPa.

Example 3:

the welding wire comprises the following chemical components in percentage by weight: 0.08 percent of C; 0.5 percent of Si; 0.6 percent of Mn; p is 0.010 percent; 0.001% of S; 21% of Cr; 12 percent of Co; 8.5 percent of Mo; 0.5 percent of W; 0.0019% of N; 0.002% of O; the balance being Ni and unavoidable impurity elements. The welding wire of the embodiment adopts narrow-gap hot wire TIG welding, and the specification of the C-HRA-2 alloy pipe is as follows: outer diameter phi 510mm multiplied by wall thickness 85mm, welding wire specification: Φ 1.6mm, welding parameters: and (3) priming parameters: the current is 120A, the voltage is 10V, the wire feeding speed is 70cm/min, the welding speed is 110mm/min, the protective gas is high-purity argon (not less than 99.99 percent), and the flow is 25L/min; filling parameters: the current is 150A, the voltage is 11V, the wire feeding speed is 90cm/min, the welding speed is 70mm/min, the protective gas is high-purity argon (more than or equal to 99.99 percent), and the flow rate is 27L/min; and (3) the parameters of the cover surface: the current is 170A, the voltage is 10V, the wire feeding speed is 70cm/min, the welding speed is 50mm/min, the protective gas is high-purity argon (not less than 99.99 percent) and the flow is 30L/min. The interlayer temperature is 120 ℃; and carrying out heat treatment after no welding. The welding joint is qualified by 100% of ray inspection, and the mechanical properties of the welding seam metal are as follows: impact work at room temperature is 140J; the tensile strength at room temperature is 740MPa, and the yield strength is 461 MPa.

By adopting the scheme, the welding deposited metal components not only have chemical components similar to those of the parent metal, but also have excellent physical and mechanical properties and excellent impact toughness matched with the parent metal; excellent welding process performance, small splashing during welding, good fluidity of weld metal, good weld forming, excellent crack resistance sensitivity, and is particularly suitable for weldingIs strain age-crack, and the welding seam has no large block rich Mo formed by Mo element microsegregation₆And meanwhile, the production cost of the phase C is 10-15% lower than that of the conventional ERNiCrCoMo-1 welding wire, and an ideal matched welding material is provided for promoting the engineering application of the novel heat-resistant alloy C-HRA-2.

Claims

1. A solid solution strengthening type welding wire for C-HRA-2 argon arc welding of heat-resistant alloy is characterized by comprising the following components in percentage by weight: 0.05 to 0.10 percent of C; si is less than 1.0 percent; mn is less than 1.0 percent; p is less than or equal to 0.015 percent; s is less than or equal to 0.001 percent; 20-22% of Cr; 10-13% of Co; 8.1 to 8.8 percent of Mo; 0.1 to 1.0 percent of W; n is less than or equal to 0.002%; o is less than or equal to 0.002 percent; the balance being Ni and unavoidable impurity elements;

welding performance: the sensitivity of thermal crack resistance is improved by 90 percent, the welding strain aging cracks of the alloy are eliminated fundamentally, and the room-temperature impact energy of a welding joint is more than or equal to 110J; tensile strength R at room temperature_mNot less than 720MPa, yield strength R_p0.2More than or equal to 460MPa, and the elongation is more than or equal to 35 percent.