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CN-122007712-A - High-strength and high-toughness iron-nickel base alloy welding wire, preparation method thereof and postweld heat treatment process

CN122007712ACN 122007712 ACN122007712 ACN 122007712ACN-122007712-A

Abstract

A high-strength and high-toughness iron-nickel base alloy welding wire, a preparation method thereof and a post-welding heat treatment process belong to the technical field of welding materials. The chemical components and the mass percentage of the alloy are C≤0.05%,Si≤0.15%,Mn≤0.35%,Cr：14～16%,Mo：3～5%,Al：1.8～2.2%,Ti：2.5～3.0%,Nb：2.5～3.5%,Ta：2.0～2.5%,Ni：35～38%,P≤0.005%,S≤0.002%,, and the balance of Fe and unavoidable impurities. The preparation method comprises the working procedures of vacuum smelting, electroslag remelting, high-temperature homogenization, forging cogging, wire rod rolling, wire rod solid solution and welding wire drawing. The iron-nickel base alloy welding wire prepared by the invention has good toughness matching in 298K and 4.2K temperature ranges after welding and postwelding heat treatment, and the preparation flow is simple.

Inventors

  • SUN ZHIYAN
  • SHE YADONG
  • HAN YANGUANG
  • LI RUI
  • ZHANG ZHEN
  • ZHANG ZEFENG
  • WU YINGFEI
  • JI SHUANG
  • FAN MINGQIANG
  • XIE LEIPENG
  • ZHAO ZHENGRONG
  • ZHANG CAIDONG
  • YAN WENJIN
  • SONG YUE
  • ZHAO NAN
  • BAI LIJUAN
  • ZHANG DAWEI
  • ZHANG YUNFEI
  • ZHAO YINGLI
  • Zhou Zetao
  • REN SHUAI
  • CHEN WEN
  • ZHANG ZHIWANG
  • CHEN WEI

Assignees

  • 河北河钢材料技术研究院有限公司
  • 河钢集团有限公司
  • 河钢股份有限公司

Dates

Publication Date
20260512
Application Date
20260122

Claims (10)

  1. 1. A high-strength and high-toughness iron-nickel base alloy welding wire is characterized in that the welding wire comprises the following chemical components in percentage by mass of ：C≤0.05%,Si≤0.15%,Mn≤0.35%,Cr：14～16%,Mo：3～5%,Al：1.8～2.2%,Ti：2.5～3.0%,Nb：2.5～3.5%,Ta：2.0～2.5%,Ni：35～38%,P≤0.005%,S≤0.002%, and the balance of Fe and unavoidable impurities; Wherein, the mass percent of Mo, nb, ta, al, ti elements satisfies the relation: 3.65≤Mo+0.1Nb+0.2Ta≤5.65;0.6≤Al/Ti≤0.8。
  2. 2. The high strength and toughness iron-nickel based alloy welding wire according to claim 1, wherein the diameter of the welding wire is 1.2-2.0 mm.
  3. 3. The method for preparing the high-strength and high-toughness iron-nickel base alloy welding wire according to claim 1 or 2, which is characterized by comprising the working procedures of vacuum smelting, electroslag remelting, high-temperature homogenization, forging cogging, wire rod rolling, wire rod solid solution and wire rod drawing; and the high-temperature homogenization procedure is to keep the temperature of the casting blank at 1150-1200 ℃ for 48-100 hours and perform homogenization treatment.
  4. 4. The method for producing a high-strength and high-toughness iron-nickel base alloy welding wire according to claim 3, wherein in the forging and cogging process, a homogenized casting blank is cooled to 1100-1150 ℃ in a furnace, and after heat preservation for 2-5 hours, the casting blank is forged into a square blank, and the final forging temperature is more than or equal to 900 ℃.
  5. 5. The method for producing a high strength and toughness iron-nickel base alloy welding wire according to claim 4, wherein the wire rod rolling process is performed by heating the square billet to 1100-1150 ℃, preserving heat for 2-5 hours, and then rolling the square billet into a wire rod with phi 8mm, wherein the final rolling temperature is more than or equal to 900 ℃.
  6. 6. The method for producing a high strength and toughness iron-nickel base alloy welding wire according to claim 5, wherein the wire rod is heated to 1050-1080 ℃ in the wire rod solid solution process, kept for 30-60 min, subjected to solid solution treatment, and cooled to room temperature by water.
  7. 7. The method of manufacturing a high strength and toughness iron-nickel based alloy wire according to claim 6, wherein the wire drawing step is performed to obtain a finished wire by performing surface treatment on the wire rod after solution treatment and then performing multi-pass drawing to a target diameter.
  8. 8. The post-weld heat treatment process of a high-strength and toughness iron-nickel base alloy welding wire according to claim 7, wherein the wire drawing process is performed with an intermediate annealing treatment at 1050-1080 ℃ when the accumulated deformation amount reaches 40-60% in the drawing process.
  9. 9. The post-weld heat treatment process of a high strength and toughness iron-nickel based alloy welding wire according to claim 8, comprising the steps of: (1) Solution treatment, namely heating the welding piece to 950-1020 ℃, preserving heat for 1-5 hours, and then cooling the welding piece to room temperature by water, and carrying out solution treatment; (2) And (3) performing double-stage aging treatment, namely heating the welding piece subjected to solution treatment to 700-750 ℃, preserving heat for 5-10 hours, then furnace cooling to 600-650 ℃, preserving heat for 5-10 hours, and performing double-stage aging treatment.
  10. 10. The post-weld heat treatment process of high strength and toughness iron-nickel based alloy welding wire according to claim 9, wherein the yield strength of the heat treated welded joint is equal to or more than 850MPa, the tensile strength is equal to or more than 1150MPa, the elongation is equal to or more than 20%, the fracture toughness is equal to or more than 130 MPa-m 1/2 , the yield strength is equal to or more than 1050MPa, the tensile strength is equal to or more than 1680MPa, the elongation is equal to or more than 30% and the fracture toughness is equal to or more than 220 MPa-m 1/2 at 298K.

Description

High-strength and high-toughness iron-nickel base alloy welding wire, preparation method thereof and postweld heat treatment process Technical Field The invention belongs to the technical field of welding materials, and particularly relates to a high-strength and high-toughness iron-nickel-base alloy welding wire, a preparation method thereof and a post-welding heat treatment process. Background Iron-nickel based alloys (generally referred to as alloys having a nickel content of 30-55 wt.%) have become an irreplaceable core structural material for critical equipment in advanced low temperature engineering by virtue of their unique combination of austenitic stability and excellent toughness at room temperature, low temperature, or even ultra-low temperature environments. The alloy is widely applied to the important technological infrastructure and the front field with extreme requirements on material performance, such as superconducting magnet structures of international thermonuclear fusion experimental reactor (ITER), particle accelerator vacuum chambers, liquid hydrogen (-253 ℃) and liquid helium (-269 ℃) storage and transportation equipment, deep space probe fuel storage tanks and the like. In these applications, welding is an indispensable key element in the manufacturing process, and the performance of the welded joint, in particular its strength, toughness and stability under the action of thermal cycles, directly determine the service safety, operational reliability and service life of the whole equipment. At present, aiming at the welding of the high-performance iron-nickel base alloy, the engineering practice mainly faces the challenge of insufficient welding material matching, and the prior art scheme generally adopts the following two types of welding materials: Austenitic stainless steel weldments such as ER309L, ER L, etc. The main advantages of the welding material are low cost and mature process. However, the fundamental disadvantage is that the alloy system design differs significantly from the iron-nickel based alloys. The nickel content is low, chromium is used as a main alloy element, so that the room temperature and low temperature strength of weld metal is obviously lower than that of a base metal, a 'low-matching' joint is formed, the joint becomes a weak link in the whole structure, and the strength requirement of a high-bearing structural member cannot be met. High temperature nickel base alloy welding materials such as ERNiCrMo-3 (Hastelloy C-276 alloy welding wire), ERNiCrFe-7 (Inconel 600 alloy welding wire) and the like. Although the welding materials have better high-temperature performance and corrosion resistance, the alloy design is not optimized for room temperature and low-temperature strength and toughness. The main problems are that the room temperature yield strength of the weld metal is generally difficult to reach more than 900MPa, the weld metal cannot be matched with the high-strength tough iron-nickel base metal with the yield strength exceeding 1000MPa at equal strength, and the weld metal has the problem of insufficient toughness at extremely low temperature. Therefore, when the conventional commercial welding material is used for welding the high-strength and high-toughness iron-nickel base alloy, the comprehensive requirements of high strength and high toughness are difficult to meet. Therefore, developing a novel special welding wire to enable weld metal to have high strength and high toughness matched with advanced iron-nickel base metal in a range from room temperature to extremely low temperature is an urgent problem to be solved in the technical field of low-temperature engineering. Disclosure of Invention The invention aims to solve the technical problem of insufficient matching property of a high-performance iron-nickel-base alloy welding material through component design, a preparation method and a post-welding heat treatment process. In order to achieve the aim of the invention, the technical scheme adopted by the invention is as follows: A high-strength and high-toughness iron-nickel base alloy welding wire comprises the following chemical components in percentage by mass as ：C≤0.05%,Si≤0.15%,Mn≤0.35%,Cr：14～16%,Mo：3～5%,Al：1.8～2.2%,Ti：2.5～3.0%,Nb：2.5～3.5%,Ta：2.0～2.5%,Ni：35～38%,P≤0.005%,S≤0.002%, and the balance of Fe and unavoidable impurities, wherein the percentage by mass of Mo, nb, ta, al, ti element satisfies the relation: 3.65≤Mo+0.1Nb+0.2Ta≤5.65;0.6≤Al/Ti≤0.8。 the diameter of the welding wire is 1.2-2.0 mm. The action mechanism of each main element in the high-strength and high-toughness iron-nickel base alloy welding wire is as follows: The C element mainly forms reinforced MC carbide with Nb, ta and the like, and has a certain contribution to the strength and hardness of the alloy, however, too high C content can consume too much Nb and Ta to form massive carbide, become a crack source, and possibly increase the thickness of a grain boundary ca