CN-117488034-B - Heat treatment method for manufacturing low alloy steel/duplex stainless steel structural member by additive
Abstract
The invention discloses a heat treatment method for manufacturing a low alloy steel/duplex stainless steel structural member by additive manufacturing, which comprises the following steps of carrying out surface treatment on a low alloy steel substrate, sequentially adding low alloy steel and duplex stainless steel on the low alloy steel substrate to obtain the low alloy steel/duplex stainless steel structural member, placing the low alloy steel/duplex stainless steel structural member manufactured by additive manufacturing in the step one into a box-type resistance furnace for heating, heating to a preset temperature, keeping the temperature of the low alloy steel/duplex stainless steel structural member at a constant temperature, taking out a test piece for quenching and rapidly cooling after the heat preservation is finished. The method improves the structural uniformity and mechanical properties of the low alloy steel/duplex stainless steel composite structure.
Inventors
- LI JIHONG
- MAO WEI
- LIU ZHIBO
- MA KE
- XUE TIANQI
- LI CHAOXU
Assignees
- 西安理工大学
Dates
- Publication Date
- 20260508
- Application Date
- 20231023
Claims (2)
- 1. The heat treatment method for additively manufacturing the low alloy steel/duplex stainless steel structural member is characterized by comprising the following steps of: carrying out surface treatment on a low alloy steel substrate, and then sequentially adding low alloy steel and duplex stainless steel on the low alloy steel substrate to obtain a low alloy steel/duplex stainless steel structural member; The method comprises the steps of sequentially adding low alloy steel and duplex stainless steel on a low alloy steel substrate to obtain a low alloy steel/duplex stainless steel structural member, wherein a cold metal transition welding method is adopted, firstly ER50-6 welding wires are used for manufacturing the low alloy steel on the low alloy steel substrate, the technological parameters are that welding current is 170A-180A, welding voltage is 18.6V-19V, welding speed is 0.20 mm/min-0.25 mm/min, welding amplitude is 6mm-8mm, shielding gas is mixed gas with the volume fraction of 80% Ar+ and the volume fraction of 20% CO 2 , the sum of the volume percentages of the components is 100%, after the low alloy steel is manufactured, a cold metal transition method is continuously used, ER2209 welding wires are used as raw materials for additive manufacturing of the duplex stainless steel, and the technological parameters are that welding current is 130A-140A, welding voltage is 20V 21V, welding speed is 0.23 mm/min-0.27 mm/min, welding amplitude is 6-8mm, shielding gas is 100% Ar, and the composite Ar/duplex stainless steel is obtained; Step two, placing the low alloy steel/duplex stainless steel structural member obtained by the additive manufacturing in the step one into a box-type resistance furnace for heating; In the second step, the heating temperature is 1060-1140 ℃, the heating rate is set to be 200-300 ℃ per minute, and the heating rate is kept constant; heating to a preset temperature, and then keeping the low alloy steel/duplex stainless steel structural member at a constant temperature for 1h; Step four, after the heat preservation is finished, taking out the test piece, quenching and rapidly cooling; In the fourth step, the cooling mode is water cooling, and the cooling rate is 300-400 ℃ per minute.
- 2. The heat treatment method for manufacturing the low alloy steel/duplex stainless steel structural member by additive manufacturing according to claim 1, wherein in the first step, the specific process of carrying out surface treatment on the low alloy steel substrate is that the low alloy steel substrate is polished until the surface has metallic luster, then the low alloy steel substrate is placed in an ultrasonic vibration instrument filled with absolute ethyl alcohol for cleaning, oil stains on the surface are removed, and the low alloy steel substrate is dried.
Description
Heat treatment method for manufacturing low alloy steel/duplex stainless steel structural member by additive Technical Field The invention belongs to the technical field of material heat treatment, and particularly relates to a heat treatment method for manufacturing a low alloy steel/duplex stainless steel structural member by additive. Background Heterogeneous materials or gradient functional materials can have specific localized properties through varying spatial chemistry and microstructure. So as to adapt to various complex service environments. Wherein the bimetal composite structure is composed of two different metals, and combines the distinct characteristics (thermal, physical, mechanical) of dissimilar metals. The low alloy steel/duplex stainless steel bimetal composite structure not only has the excellent corrosion resistance of the duplex stainless steel, but also has the advantage of low cost of the low alloy steel. In practical application, the cost can be saved, and the waste is avoided. Compared with the traditional rolling, casting and other modes, the arc additive manufacturing technology can directly mold according to the three-dimensional data of the workpiece, and can realize the molding of parts with complex shapes. The arc additive manufacturing technology using wires as raw materials is high in efficiency and low in cost, and can manufacture various materials according to a certain sequence, so that the arc additive manufacturing technology is a key technology for manufacturing heterogeneous material structures. However, the direct energy deposition approach of fabricating bi-metallic composite structures using wire arc additive results in strong microstructural anisotropy, residual stresses at the interface, and deformation. Due to the thermal cycling and complex heat build-up processes of additive manufacturing, the microstructure of the resulting structural member of the additive manufacturing is quite complex, and thus the microstructure and phase composition must be tailored to achieve the desired properties. The heat treatment is an effective way for controlling the microstructure and mechanical property of the bimetal composite structure, and the microstructure of the bimetal structure can be more uniform through the heat treatment, so that the mechanical property is obviously improved. In the prior art, the manufacturing process of the low alloy steel/duplex stainless steel composite structure has been studied, but the heat treatment method of the composite structure has been studied less, so that the further improvement of the structural uniformity and the mechanical property of the additive manufacturing low alloy steel/duplex stainless steel composite structure is challenging. Disclosure of Invention The invention aims to provide a heat treatment method for manufacturing a low alloy steel/duplex stainless steel structural member by additive, which improves the structural uniformity and mechanical properties of a low alloy steel/duplex stainless steel composite structure. The technical scheme adopted by the invention is that the heat treatment method for manufacturing the low alloy steel/duplex stainless steel structural member by additive manufacturing is carried out according to the following steps: carrying out surface treatment on a low alloy steel substrate, and then sequentially adding low alloy steel and duplex stainless steel on the low alloy steel substrate to obtain a low alloy steel/duplex stainless steel structural member; Step two, placing the low alloy steel/duplex stainless steel structural member obtained by the additive manufacturing in the step one into a box-type resistance furnace for heating; heating to a preset temperature, and then keeping the low alloy steel/duplex stainless steel structural member at a constant temperature; And fourthly, taking out the test piece after heat preservation is finished, and quenching and rapidly cooling the test piece. The present invention is also characterized in that, The specific process of the surface treatment of the low alloy steel substrate comprises the steps of polishing the low alloy steel substrate until the surface has metallic luster, then placing the low alloy steel substrate in an ultrasonic vibration instrument filled with absolute ethyl alcohol for cleaning, removing oil stains on the surface, and airing. The method comprises the steps of sequentially adding low alloy steel and duplex stainless steel on a low alloy steel substrate to obtain a low alloy steel/duplex stainless steel structural member, wherein a cold metal transition welding method is adopted, ER50-6 welding wires are firstly used for manufacturing the low alloy steel on the low alloy steel substrate, the technological parameters are 170A-180A of welding current, 18.6-19V of welding voltage, 0.20-0.25 mm/min of welding speed, 6-8mm of welding amplitude, the shielding gas is mixed gas with the volume fraction of 80% Ar+ and the volume frac