CN112846565A

CN112846565A - Solid welding wire for pure solid solution strengthening type heat-resistant alloy C-HRA-2 submerged arc welding

Info

Publication number: CN112846565A
Application number: CN202011637892.8A
Authority: CN
Inventors: 刘正东; 陈正宗; 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: 2021-05-28
Anticipated expiration: 2040-12-31
Also published as: CN112846565B

Abstract

A solid welding wire for pure solid solution strengthening type heat-resistant alloy C-HRA-2 submerged arc welding belongs to the technical field of heat-resistant alloy welding materials. The solid 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 alloy has the advantages that the hot crack resistance sensitivity is improved by 90 percent, the welding strain aging cracks of the alloy are eliminated fundamentally, the welding process has good manufacturability, easy slag removal, attractive weld forming and no defects of slag adhesion, pits and the like on the surface; the welding process has excellent performance, good metal fluidity of welding seams, good formability of welding seams and low cost.

Description

Solid welding wire for pure solid solution strengthening type heat-resistant alloy C-HRA-2 submerged arc welding

Technical Field

The invention belongs to the technical field of heat-resistant alloy welding materials, and particularly provides a solid welding wire for pure solid solution strengthening type heat-resistant alloy C-HRA-2 submerged arc welding, which is suitable for automatic submerged arc welding of novel heat-resistant alloy C-HRA-2 related pipelines.

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 State energy agency has formally repeated the great Tangshan Dongye 37075, the 630 ℃ ultra-supercritical national electric power demonstration project in cities is the first thermal power generating unit in the world with the highest steam parameter, 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 selectable materials in the engineering in the world at present

A martensitic heat-resistant steel. The G115 steel is a novel martensite heat-resistant steel (patent number: ZL 201210574445.1) which is independently researched and developed for more than ten years by the inventor team and can be used for steam parameters of 630-650 ℃, and through the joint participation and the cooperative attack of a whole chain unit in the construction of electric stations such as 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 distribution plant, a welding material plant and the like, the engineering welding problem which restricts the final difficult problem of the engineering application of the G115 steel, namely a large-caliber thick-wall pipe (the maximum wall thickness of engineering application is 120mm) is thoroughly solved in 6 months in 2020, and the batch and stable engineering supply conditions of the G115 boiler pipe are 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, new materials which are independently researched and developed must solve the engineering welding problem, including development of matched welding materials and welding processes.

In order to lead the development of the world thermal power technology, further reduce the coal consumption and improve the heat efficiency, several power groups in China actively demonstrate 650-. Under the leadership and organization of the national department of science and technology and energy agency, an autonomous controllable 630- & ltSUB & gt plus one's complement 700 ℃ ultra-supercritical coal-fired boiler material system is successfully constructed in China, wherein the pure solid solution strengthening type nickel-based heat-resistant alloy

(patent)Number: ZL 201510813308.2) and

(patent No. ZL 201410095587.9) is one of the candidate materials of the ultra-supercritical coal-fired power station boiler pipeline at 650 ℃ and 700 ℃ in the future, and the industrial manufacturing of boiler pipes with basically all dimensions of novel heat-resistant materials required by power station boiler construction is completed, and a solid material foundation is provided for the selection of materials of ultra-supercritical power station boilers at 650 ℃ in China.

The alloy is as follows

Based on the (opposite standard Inconel 617B) alloy, the gamma' phase (Ni) is removed₃(Al, Ti)) form elements Al and Ti, and the self-developed pure solid solution strengthening type nickel-based heat-resisting alloy initially has market admittance evaluation conditions. (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. In a common welding method, the submerged automatic welding has high production efficiency, and a boiler factory generally adopts a submerged automatic welding mode to weld large-diameter pipes such as headers and the like when constructing boilers. However, the nickel-based alloy has a complex component system, more types of elements are added in a matrix, and compared with martensite or austenite heat-resistant steel, the welding crack sensitivity is higher, and the welding crack is easy to appear. 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 formation mechanism of the liquification cracks and the crystal cracks is the same, mainly because the weak low-melting phase or eutectic structure exists between the crystals and bears higher stress action in the welding thermal cycle processAnd is cracked. 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 a precipitation-strengthened nickel-base alloy is subjected to aging treatment 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)

In Europe, 700 ℃ ultra-supercritical power station material selection research is started in 1998, a 700 ℃ test platform is established in a German E.ON Scholven power plant, an Inconel 617 modified alloy Inconel 617B, also called CCA 617, is examined for a large-caliber thick-wall pipeline for nearly two years, and the phenomenon that the welding heat affected zone of the large-caliber thick-wall pipeline has annular cracks is found. 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(UNS N06617) and its improved alloy common welding materials are special matched welding rods (AWS A5.11: ENiCrCoMo-1, ISO 14172ENi6117 and GB/T13814: ENi6117) and welding wires (AWS A5.14: ERNiCrCoMo-1, ISO 18274SNi6117 and GB/T15620: SNi 6117). The Inconel 617 special matched welding rod core 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 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 Inconel 617 special-purpose matching 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; cr 20.0-24.0%; 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, in particular in the wire composition, Al is specified: 0.8 to 1.5 percent; easily cause strain aging cracks of the welding joint. In order to improve the strain aging cracks of Inconel 617 and the improved alloy welding joint thereof, the strain aging cracks can be relieved by post-welding stress relief annealing heat treatment (980 ℃/3h/AC), but are difficult to eliminate 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 welding joint are difficult to eliminate fundamentally, and from the aspect of engineering application, a special matched welding material for submerged arc welding is needed to be developed aiming at the physical metallurgy characteristics of the 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 ℃.

Patent CN 105215578A, "submerged arc welding agent, welding wire and welding method of nickel base alloy", the welding wire composition is according to the mass percent: 0.019% of C; 2.95 percent of Mn; 0.13 percent of Si; 0.002% of S; 0.008% of P; 70.70 percent of Ni;20.88 percent of Cr; 2.41 percent of Nb; 0.01 percent of Cu; 0.35 percent of Ti; 1.70 percent of Fe; the balance of trace impurities; meanwhile, the nickel-based alloy submerged arc welding flux is prepared from the following components: 5-8 parts of Mn; al (Al)₂O₃34-36 parts by weight; CaF₂52-54 parts by weight; 2-3 parts of Cr; k₄TiO₄3-4 parts by weight; the welding wire contains gamma' phase (Ni)₃(Al, Ti)) form the element Ti 0.35% for welding of Inconel 600, 601 alloy and Incoloy 800 alloy themselves and between them and carbon steel or stainless steel, but also for welding of 9Ni steel.

The welding wire and the welding flux have the technical problems that the chemical components, the mechanical properties and the like of deposited metal are poor in matching with the base metal pure solid solution strengthening type heat-resistant alloy C-HRA-2, and the like, which cannot be overcome. The national energy agency is planning a 650 ℃ ultra-supercritical demonstration power station, the novel nickel-based heat-resistant alloy C-HRA-2 is one of candidate materials of a pipeline related to a 650 ℃ ultra-supercritical demonstration unit, and novel welding wires and welding fluxes which are matched with the novel nickel-based heat-resistant alloy C-HRA-2, low in cost and high in crack resistance sensitivity are 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 power strategic layout is promoted, the world thermal power technology is led, and important strategic significance and engineering value are achieved. Therefore, the solid welding wire for submerged-arc welding of the solid solution strengthened novel heat-resistant alloy C-HRA-2 is forced to be quick.

Disclosure of Invention

The invention aims to provide a solid welding wire for submerged arc welding of pure solid solution strengthening type heat-resistant alloy C-HRA-2. By considering the components and the comprehensive performance of the novel heat-resistant alloy C-HRA-2, the characteristics of welding practicability in engineering, high-temperature service requirements of joints and the like, the 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 the 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 technical scheme adopted by the invention for solving the technical problem is as follows:

the solid 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 solid welding wire 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 100J; 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 0.06-0.12%.

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 facilitated by increasing the Cr content, the endurance strength is reduced by excessively increasing the Cr content, the resistivity is increased strongly by the Cr element, the resistivity of the core wire is reduced by the transition of the Cr element in the coating, and the electrode is free from red tail. Therefore, the Cr content in the welding wire is controlled to be 20-22 percent.

Co: its main role 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 also increase the solubility of Cr, Mo, W, and C in the γ matrix, further enhancing the solid solution strengthening effect. 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 endurance strength of the alloy. 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, the maximum solid solution strength of the deposited metal matrix is obtained, and not only the higher the content of the solid solution strengthening element is, the better the solid solution strength is, the solid solubility of the Ni matrix is considered, but also the matching between C, Co and Cr element is considered, so as to achieve the purpose of the optimal solid solution strength. The content of Mo element in the alloy is controlled to be 8.1-8.8%. In order to achieve the maximum solid solution strengthening effect by matching with Mo, and simultaneously, segregation does not occur in deposited metal, and the W element is controlled to be 0.1-1.0%.

N: 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 to form BN in the process of molten pool metal solidification, if the content of N is too high, coarse BN particles can be formed, and when the toughness of the alloy is weakened,the B element for grain boundary strengthening is also consumed, thereby seriously impairing the high-temperature permanent strength of the deposited metal. 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 in the welding wire is controlled to be less than or equal to 0.0025 percent.

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 O is respectively controlled to be less than or equal to 0.0025 percent; p is less than or equal to 0.015 percent; s is less than or equal to 0.001 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 of the comprehensive action of each element, particularly no Al and Ti elements, and simultaneously the content of O, N, S, P and five-harmful elements is strictly controlled, the thermal crack resistance sensitivity is improved by 90 percent as a whole, the welding strain aging cracks of the alloy are fundamentally eliminated, the welding process has good manufacturability, easy slag removal, attractive weld forming, no slag sticking, pits and other defects on the surface and the like; 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 100J; 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; and the welding process has excellent performance, good metal fluidity of the welding seam, good welding seam formability and 10 to 15 percent lower cost than the prior ERNiCrCoMo-1 welding wire.

Detailed Description

The present invention will be further described with reference to the following specific examples. The following examples are all made into wire rods according to the conventional welding wire smelting process, and the wire rods are drawn to the diameters phi 1.6 and phi 2.4mm, and then 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; 13 percent of Co; 9.0 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 is matched with a conventional welding flux, automatic submerged arc welding is adopted, and the specification of a C-HRA-2 alloy pipe is as follows: phi 510 × 70mm, wire gauge: phi 2.4mm, and the welding parameters are as follows: the welding current is 340A, the arc voltage is 28V, the preheating temperature is 150 ℃, and the interlayer temperature is 90 ℃. 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 105J; the tensile strength at room temperature is 775MPa, and the yield strength is 460 MPa.

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 is matched with a conventional welding flux, automatic submerged arc welding is adopted, and the specification of a C-HRA-2 alloy pipe is as follows: phi 510 × 70mm, wire gauge: phi 2.4mm, and the welding parameters are as follows: the welding current is 330A, the arc voltage is 30V, the preheating temperature is 150 ℃, and the interlayer temperature is 90 ℃. 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; tensile strength at room temperature is 790MPa, and yield strength is 470 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 is matched with a conventional welding flux, automatic submerged arc welding is adopted, and the specification of a C-HRA-2 alloy pipe is as follows: phi 510 × 70mm, wire gauge: phi 1.6mm, and welding parameters are as follows: the welding current is 320A, the arc voltage is 30V, the preheating temperature is 150 ℃, and the interlayer temperature is 90 ℃. 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 120J; the tensile strength at room temperature is 795MPa, and the yield strength is 475 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; the welding process has the advantages of excellent performance, small splashing during welding, good metal fluidity of a welding line, good formation of the welding line, excellent crack sensitivity resistance, particularly strain aging cracks, and simultaneously, the cost is 10-15 percent lower than that of the existing ERNiCrCoMo-1 welding wire, thereby providing an ideal matched welding material for submerged arc welding for promoting the engineering application of novel heat-resistant alloy C-HRA-2.

Claims

1. A solid welding wire for submerged arc welding of pure solid solution strengthening type heat-resistant alloy C-HRA-2 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;