CN-122007589-A - Electron beam welding method for high-carbon high-chromium stainless steel

Abstract

The invention belongs to the field of welding, and particularly relates to a high-carbon high-chromium stainless steel electron beam welding method; the welding method comprises the steps of welding a workpiece to be welded by adopting an electron beam welding method, and then carrying out online tempering scanning, wherein the workpiece to be welded is a workpiece obtained by clamping and fixing a stainless steel part A, a vanadium layer and a stainless steel part B in sequence, and the stainless steel part A and the stainless steel part B both contain carbon with the mass percent of more than or equal to 0.95% and chromium with the mass percent of more than or equal to 16%. The welding method can lead the tensile strength of the welding line to be 1250-1450MPa, the bending strength to be 2020-2250MPa, the center hardness of the welding line to be 570-650MPa and the deformation to be 0.20-0.25mm.

Inventors

• LUO BINGBING
• FANG WEIPING
• YI YAOYONG
• YANG MAOHONG

Assignees

• 广东省科学院中乌焊接研究所

Dates

Publication Date

20260512

Application Date

20260313

Claims (10)

1. 1. The electron beam welding method for the stainless steel is characterized by comprising the following steps of: welding the workpiece to be welded by adopting an electron beam welding method, and then carrying out online tempering scanning; the workpiece to be welded is a workpiece obtained by clamping and fixing the stainless steel part A, the vanadium layer and the stainless steel part B in sequence; The stainless steel part A contains more than or equal to 0.95% of carbon by mass and more than or equal to 16% of chromium by mass; the stainless steel part B contains more than or equal to 0.95% of carbon by mass and more than or equal to 16% of chromium by mass.
2. 2. A method of electron beam welding stainless steel according to claim 1, wherein said electron beam welding method comprises at least one of the following: (a1) The accelerating voltage is 120-150 kV; (a2) The beam intensity is 15-25 mA; (a3) The welding speed is 600-1000 mm/min; (a4) Defocusing is selected for focusing current, and the focusing current is 2450-2550mA; (a5) The diameter of the beam spot is 0.3-0.45mm; (a6) The scanning mode is to scan by adopting any mode selected from circular wave, triangular wave or sawtooth wave, and the scanning amplitude is 0.5-1.5mm.
3. 3. A method of electron beam welding stainless steel according to claim 1, wherein said in-line temper scan is characterized by at least one of: (b1) The online tempering scanning adopts an electron beam defocusing heating mode, so that defocusing electron beams do reciprocating scanning movement in a welding line area; (b2) The accelerating voltage is 120-150 kV; (b3) The beam intensity is 5-8mA; (b4) The welding speed is 1500-3000mm/min; (b5) Defocusing under the focusing current selection, wherein the focusing current is 2200-2300mA; (b5) The scanning times are 60-100 times; (b6) The peak surface temperature of the weld zone is 450-550 ℃.
4. 4. A method of electron beam welding for stainless steel according to claim 1, wherein a butt gap between the stainless steel member A and the stainless steel member B is 0.05mm or less; and/or the residual magnetic induction intensity of the stainless steel component A and the stainless steel component B is less than or equal to 2Gs; And/or the vanadium layer contains more than or equal to 99.5 mass percent of vanadium.
5. 5. A method of electron beam welding stainless steel according to claim 1, wherein said welding and/or said on-line tempering scanning is performed at a vacuum level of 7X 10 -5 mbar or more.
6. 6. A method of electron beam welding for stainless steel according to claim 1, wherein the stainless steel part A and the stainless steel part B are subjected to machining, polishing, cleaning and demagnetizing treatment respectively on the butt joint surfaces of the stainless steel part A and the stainless steel part B before use, so that the butt joint gap between the stainless steel part A and the stainless steel part B is less than or equal to 0.05mm, and the residual magnetic induction intensity of the stainless steel part A and the stainless steel part B is less than or equal to 2Gs.
7. 7. A method of electron beam welding for stainless steel according to any one of claims 1 to 6, wherein the vanadium layer has a thickness T and the total thickness of the stainless steel member A and the stainless steel member B is T, and the ratio of T to T satisfies T/T=0.01 to 0.03.
8. 8. The stainless steel product is characterized by comprising a stainless steel part A, an intermediate connecting layer and a stainless steel part B, wherein the stainless steel part A and the stainless steel part B are connected through the intermediate connecting layer; the stainless steel product is obtained by welding by adopting the stainless steel electron beam welding method according to any one of claims 1 to 7.
9. 9. The stainless steel product according to claim 8, wherein the intermediate connecting layer contains at least one of equiaxed crystals, carbides and columnar crystals; and/or, the average grain size of the intermediate connection layer is 10-40 μm; And/or the stainless steel product is selected from a cutter, a rotating shaft, a die, or a bearing.
10. 10. Use of the stainless steel product according to any one of claims 8-9 in mechanical equipment, transportation equipment or electronic products.

Description

Electron beam welding method for high-carbon high-chromium stainless steel Technical Field The invention belongs to the technical field of welding, and particularly relates to an electron beam welding method for high-carbon high-chromium stainless steel. Background With the rapid development of numerical control technology, more and more machine tool equipment is developed to high precision, high speed and high intelligence. The ultra-high speed rotating shaft is a core functional component of a high-grade numerical control machine tool, and the raw materials of the ultra-high speed rotating shaft need to have the characteristics of high strength, high hardness, high wear resistance, high temperature resistance and oxidation resistance. The high-carbon high-chromium stainless steel (such as 9Cr18 Mo) contains various alloy elements such as Cr, mo, ni and the like, has high C and Cr contents and a large number of carbides after heat treatment, has good strength, hardness and creep resistance, is widely applied to high-end cutters, precision dies, bearings and wear-resistant parts, and is also a preferred material of a new generation of ultra-high-speed rotating shafts. Because the structural design of the ultra-high speed rotating shaft is complex, the integrated forming cannot be realized in the prior art, and the welding technology is required to be adopted to realize the connection between the high-carbon high-chromium flange and the rotating shaft. However, such materials have large carbon equivalent and very poor weldability. The high crack sensitivity is caused by high carbon content during welding, and the segregation of carbon during welding is very easy to form a hard and brittle carbide network, so that cracks are generated under the action of welding stress. Although the high-carbon high-chromium stainless steel has better strength and hardness, the high-carbon high-chromium stainless steel is more brittle than common stainless steel, is more sensitive to the welding heat process, and is easy to generate larger deformation and residual stress after welding. Meanwhile, large heat input is adopted in the welding process, so that coarse columnar crystals are formed in the center of a molten pool, and the toughness of the joint is seriously damaged. All the above problems result in low joint performance, which will result in serious loss of materials and great increase in production cost. This is a major technical bottleneck limiting its application to critical load bearing or impact load bearing components. Therefore, there is a need to develop more efficient welding techniques and joint strengthening processes to solve the problem of low joint performance caused by coarsening of grains and insufficient toughness of welded joints of high-carbon high-chromium stainless steel. The electron beam welding technology has high energy density, high welding speed and concentrated welding energy, can independently adjust each technological standard parameter, and is an ideal welding method for high-carbon high-chromium stainless steel materials. However, currently, aiming at the problems that the electron beam welding of a high-carbon high-chromium stainless steel joint is easy to generate cracks, coarse grains and continuous distribution of carbide along grain boundaries, which results in low joint performance and large residual stress and deformation of a welded structure, the prior art is usually a parameter optimization method, namely, the heat input amount is reduced by precisely controlling the technological parameters such as beam intensity, welding speed and the like, or complex post-welding heat treatment is carried out. However, these methods have limited effects on grain refinement, narrow process window, and poor stability. Therefore, there is a need to develop a welding process suitable for high carbon high chromium stainless steel welded joints. Disclosure of Invention In order to overcome at least one technical problem of the prior art, one of the purposes of the present invention is to provide a stainless steel electron beam welding method, wherein a metal vanadium layer is introduced into a stainless steel part A and a stainless steel part B during welding, and an on-line tempering treatment is performed immediately after welding, so as to refine a weld joint structure, reduce residual stress and deformation after welding, and improve mechanical properties of a joint. It is a second object of the present invention to provide a stainless steel product. It is a further object of the present invention to provide the use of the stainless steel product described above in mechanical equipment, transportation equipment or electronic products. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The first aspect of the invention provides a method for electron beam welding of stainless steel, comprising the steps of: welding the workpiece to be welded by a