CN113369642B - A kind of iron-based tungsten carbide and stainless steel heterogeneous additive structure and manufacturing method - Google Patents

Abstract

The invention discloses an iron-based tungsten carbide and stainless steel heterogeneous additive structure and a manufacturing method thereof. The additive manufacturing method adopts the same plasma arc, and a robot PLC alternately controls different wire feeding time of the iron-based tungsten carbide flux core and the stainless steel solid core wire, the starting time of a single additive channel of the iron-based tungsten carbide flux core wire and the starting time of a single channel between adjacent layers, so that each additive channel, the adjacent channels and the adjacent layers are in an alternate additive structure with superhard iron-based tungsten carbide and soft stainless steel regions alternately distributed. According to the invention, the wire feeding time, time and track are adjusted by heterogeneous alternate melting of the iron-based tungsten carbide flux-cored wire and the stainless steel wire, so that a heterogeneous structure with a three-dimensional superhard iron-based tungsten carbide additive region and a soft stainless steel additive region alternately distributed is realized, the combination of ultrahigh hardness and high toughness is achieved, and the difficult problem of realizing the additive of superhard and soft materials is broken through.

Description

A kind of iron-based tungsten carbide and stainless steel heterogeneous additive structure and manufacturing method

technical field

The invention belongs to the technical field of arc additive manufacturing, in particular to an iron-based tungsten carbide and stainless steel heterogeneous additive structure and a manufacturing method.

Background technique

With the rapid development of engineering technology, it is increasingly difficult to optimize and improve the performance of homogeneous metal materials to meet various requirements. The composite energy of two or more materials can expand the technical space for the performance improvement of metal components. Iron-based tungsten carbide additive parts have the characteristics of high strength and high hardness, but poor impact toughness, while stainless steel materials have better impact toughness. In addition, most of the additive materials of tungsten carbide are mainly powder materials, and the efficiency is low. Therefore, there is an urgent need for a superhard iron-based tungsten carbide and soft stainless steel alternately fused multi-dimensional heterogeneous additive structure to improve the performance of components.

The patent is a FeNi-based laser cladding doped tungsten carbide/chromium carbide composite reinforced high-temperature wear-resistant coating and its preparation method (application number CN201811022429.5), which discloses a preparation method of a tungsten carbide/chromium carbide composite coating. The method includes substrate pretreatment, surfacing treatment, laser cladding treatment, and vulcanization treatment. The steps are complicated, the resulting coating is thin, and the additive manufacturing of large-scale samples cannot be realized, and the equipment cost is relatively high. . Patent a method for plasma cladding composite tungsten carbide coating (application number CN202010068190.6) discloses a method for plasma cladding composite tungsten carbide coating. The coating prepared by this method maximizes the wear resistance of tungsten carbide without changing the impact toughness of the nickel-based alloy, but the nickel-based alloy has a high cost and cannot realize the additive manufacturing of large-scale samples.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an iron-based tungsten carbide and stainless steel heterogeneous additive structure and a manufacturing method, so as to realize a heterogeneous structure in which the three-dimensional superhard iron-based tungsten carbide additive region and the soft stainless steel additive region are alternately distributed, Achieving the combination of ultra-high hardness and high toughness, breaking through the problem of superhard and soft material additive realization; at the same time, it also effectively inhibits the generation of cracks in molten iron-based tungsten carbide additive, and breaks through the additive forming of iron-based tungsten carbide wire. Quality control problems.

To achieve the above object, the present invention adopts the following technical solutions:

A heterogeneous additive structure of iron-based tungsten carbide and stainless steel, the additive structure is distributed alternately in regions of superhard iron-based tungsten carbide and soft Cr-Ni stainless steel in the lateral X direction, the longitudinal Y direction and the vertical Z direction .

Further, in the longitudinal Y direction of the additive structure, the length of the soft Cr-Ni stainless steel region is less than the length of the superhard iron-based tungsten carbide region, the length L1 _of the iron-based tungsten carbide additive region is 24-45 mm, and the Cr-Ni region is 24-45 mm. The length L ₂ of the stainless steel additive area is 15-25 mm.

Further, in the vertical Z direction of the additive structure, the thickness of the soft Cr-Ni stainless steel region is close to the thickness of the superhard iron-based tungsten carbide region, and the thickness δ is 1-5 mm.

Further, in the lateral X direction of the additive structure, the width of the soft Cr-Ni stainless steel region is close to that of the superhard iron-based tungsten carbide region, and the width is 5-10 mm; the width of the soft Cr-Ni stainless steel region is increased. The width of each bead in the material process.

A method for manufacturing a heterogeneous additive structure based on iron-based tungsten carbide and stainless steel, comprising the following specific steps:

(1) Use a low-temperature heat treatment furnace to heat the stainless steel substrate to reach the preset temperature, select the process parameters of additive current, arc travel speed, ion gas flow rate and shielding gas flow rate, and ignite the arc on the stainless steel substrate;

(2) After igniting the arc, firstly use the robot PLC control signal to turn on the iron-based tungsten carbide wire feeding switch, the iron-based tungsten carbide wire is fed into the arc and melted according to the set wire feeding speed V _f1 , and the wire is fed according to the predetermined arc. The feeding time T ₁ of the traveling speed V _w is fixed, and the super-hard iron-based tungsten carbide additive area with a length of L ₁ is formed by melting; then the feeding of the iron-based tungsten carbide wire is closed by the robot PLC control, and the feeding of the stainless steel wire is turned on at the same time. switch, and then control the stainless steel wire to be fed into the arc at the set speed V _f2 for melting, the wire is fed for a fixed time T ₂ according to the predetermined arc travel speed V _w , and melted to form a soft Cr-Ni stainless steel additive with a length of L ₂ area; the wires of the two materials are alternately fed into the plasma arc area until the preset length of the first single-pass additive is reached, and the arc is extinguished, thereby forming the first longitudinal superhard iron-based tungsten carbide additive area and Single-pass structure with alternating areas of soft Cr-Ni stainless steel additive;

(3) The robot controls the welding torch to move to the starting point of the adjacent second additive, ignites the arc, and the iron-based tungsten carbide wire is fed into the arc to melt at the same set wire feeding speed V _f1 , and the wire feeding time is changed to On the basis of the fixed time T ₁ , reduce the track time T ₃ , so that the length of the super-hard iron-based tungsten carbide additive track at the starting end is reduced by L ₃ ; then the robot PLC is also used to control the feeding of the iron-based tungsten carbide wire to close and open at the same time. The stainless steel wire is fed into the switch, and then the stainless steel wire is controlled to be fed into the arc at the set speed V _f2 for melting, and the wire is fed for a fixed time T ₂ according to the predetermined arc travel speed V _w , and melted to form a soft material with a length of L ₂ Cr-Ni stainless steel additive area; then according to the single-pass additive method in step (2), the iron-based tungsten carbide wire is fed into the arc for melting according to the set wire feeding speed V _f1 , and the wire is fed according to the predetermined arc travel speed V _w Feeding fixed time T ₁ , melting to form a super-hard iron-based tungsten carbide additive area with a length of L ₁ ; this cycle is repeated until the preset length of the additive pass is reached; the next adjacent third pass of additive welding, The wire feeding time at the starting end of the iron-based tungsten carbide wire is reduced by 2 times the staggered time 2T ₃ from the fixed time T ₁ , and the third single-track super-hard iron-based tungsten carbide additive area and soft material are formed according to the same rule. High-quality Cr-Ni stainless steel with alternating single-pass structure of additive areas; the feeding time of the starting end of the iron-based tungsten carbide wire for the next adjacent weld bead, from a fixed time T ₁ , decreases by 3T ₃ , 4T in turn according to the number of additive passes ₃ …nT ₃ , until the time T ₂ is reduced to zero, the cycle starts again according to the feeding time T ₂ from the starting end of the iron-based tungsten carbide wire, until the size reaches the preset width of the transverse single-layer cladding, forming the first A single-channel structure in which n-channel super-hard iron-based tungsten carbide additive regions and soft Cr-Ni stainless steel additive regions alternate to complete single-layer addition, thereby forming super-hard iron-based tungsten carbide and soft Cr-Ni stainless steel in the lateral X direction The Ni stainless steel areas are all areas of alternating distribution structure;

(4) The robot controls the welding torch to move to the starting point of the first additive pass of the first layer, and then raises the same height according to the actual single-layer thickness δ, and then ignites the arc, iron-based tungsten carbide wire and stainless steel wire according to the first layer The starting end of the second wire feed reduces the staggered time T3 and starts to switch, and then the iron _- based tungsten carbide wire and the stainless steel wire are alternately fed and melted according to the fixed time T1 and T2, so as to form the _second layer of the _first supersonic wire. A single-pass structure with alternating hard iron-based tungsten carbide additive areas and soft Cr-Ni stainless steel additive areas; the second layer of the second layer, the second layer of the second layer, the third layer of the second layer, etc. Iron at the beginning of the adjacent weld bead of the second layer The feeding time of the base tungsten carbide wire is decreased by 2T ₃ , 3T ₃ ... n-1T _{3 in turn,} until the time T ₂ is reduced to zero, and the feeding time of the iron-based tungsten carbide wire at the starting point is T ₂ again, and it starts again. Cycle to complete the 2nd layer of additive; then the 1st track of each layer is the same as the 2nd track of the previous layer. The method of wire feeding and switching is the same. The n-1th lane of each layer is the same as the nth lane of the previous layer, until the predetermined height of the additive component is formed, and all the stacking is stopped. , thereby forming a structure in which the superhard iron-based tungsten carbide and soft Cr-Ni stainless steel regions in the longitudinal Y direction and the vertical Z direction of the multilayer are alternately distributed.

Further, the two alternately melted wires are iron-based tungsten carbide wires and stainless steel wires, the arc heat source is a plasma arc, the iron-based tungsten carbide wires are flux-cored wires with a diameter of 1.6 mm, and the mass fraction of tungsten carbide particles is 25. %～50%; the stainless steel wire is a solid core wire with a diameter of 1.2mm, and the grade is ER308 or ER316L.

Further, the two alternately melted _wires are iron-based tungsten carbide wires and stainless steel _wires . The speed is 1.8 ~ 5.3m/min to ensure the same single-track stacking height.

Further, when the iron-based tungsten carbide wire and the stainless steel wire are added in a single pass, the robot uses the PLC signal to control the wire feeding switch, and the arc travel speed _Vw ranges from 10 to 30 cm/min. The fixed feeding time T1 ranges from ₅ to 27s, and the stainless steel wire feeding fixed time T2 ranges from ₃ to 15s.

Further, for adjacent additive passes, the feeding time of the iron-based tungsten carbide wire material at the beginning of the latter pass is successively reduced by the mistracking time T ₃ , and the mistracking time T ₃ ranges from 1 to 3 s.

Further, for adjacent additive layers, the first pass of each layer is the same as the second pass of the previous layer, and the second pass of each layer is the same as the third pass of the previous layer. The n-1th pass of each layer is additive in the same way as the nth pass of the previous layer; n is set based on the width in the X direction and the width of the weld bead.

Compared with the prior art, the significant advantages of the present invention are as follows: 1. The three-dimensional superhard iron-based tungsten carbide additive region and the soft stainless steel additive region prepared by this method are alternately distributed to achieve a combination of ultra-high hardness and high toughness. 2. The additive parts have excellent mechanical properties, with ultra-high hardness and ultra-high impact toughness; 3. This method is suitable for the manufacture of multiple different types of three-dimensional heterogeneous large-scale additive parts , has the characteristics of flexible implementation and good flexibility; 4. This method is prepared by arc melting, and the equipment cost is lower than that of laser and electron beam cladding; 5. This method is compared with powder laser or electron beam additive. In terms of additive manufacturing, it is more efficient.

Description of drawings

Figure 1 is a schematic diagram of the first layer of a multi-dimensional heterostructure of superhard iron-based tungsten carbide and soft stainless steel alternately added. (The white area represents iron-based tungsten carbide material, and the black area represents stainless steel material)

Figure 2 is a front view of a multi-dimensional heterostructure of superhard iron-based tungsten carbide and soft stainless steel alternately added. (The white area represents iron-based tungsten carbide material, and the black area represents stainless steel material)

Figure 3 is the left view of the multi-dimensional heterostructure with the alternate additive regions of superhard iron-based tungsten carbide and soft stainless steel. (The white area represents iron-based tungsten carbide material, and the black area represents stainless steel material)

FIG. 4 is a schematic diagram of the heterostructure of the superhard iron-based tungsten carbide and the soft stainless steel layer.

Figure 5 is a flow chart of the layering procedure of superhard iron-based tungsten carbide and soft stainless steel.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

Example 1

In the multi-dimensional heterostructure of the present invention, a plasma arc is used as the heat source of the fuse, the additive current set in the additive process is 120A, the ion gas flow rate is 1.2L/min, and the protective gas flow rate is 18L/min.

Combined with Figures 1 to 3, the multi-dimensional heterostructure of superhard iron-based tungsten carbide and soft stainless steel alternately added, such as superhard iron-based tungsten carbide and soft stainless steel in the lateral X direction, the longitudinal Y direction and the vertical Z direction. The regions of Cr-Ni stainless steel are distributed alternately.

Multi-dimensional heterogeneous additive structure, in the longitudinal Y direction, the length of the soft Cr-Ni stainless steel area is less than the length of the superhard iron-based tungsten carbide area, the length L1 _of the iron-based tungsten carbide additive area is 30mm, and the Cr-Ni stainless steel increases the length of the area. The length L ₂ of the material area is 15 mm.

In the multi-dimensional heterogeneous additive structure, in the vertical Z direction, the thickness of the soft Cr-Ni stainless steel region is close to that of the superhard iron-based tungsten carbide region, and the thickness δ is 3 mm.

1-5, the manufacturing method of the multi-dimensional heterogeneous additive structure includes the following specific steps:

(1) Use a low-temperature heat treatment furnace to heat the stainless steel substrate to 100°C, select the process parameters of additive current, arc travel speed, ion gas flow rate and shielding gas flow rate, and then ignite the arc on the stainless steel substrate;

(2) After igniting the arc, firstly use the robot PLC control signal to turn on the iron-based tungsten carbide wire feeding switch, the iron-based tungsten carbide wire is fed into the arc to melt at the set 1.0m/min, and the wire travels according to the predetermined arc The feeding speed of 10 cm/min is fixed for 18s, and it melts to form a super-hard iron-based tungsten carbide additive area with a length of 30mm; then use the robot PLC to control the feeding of iron-based tungsten carbide wire to close and open the stainless steel wire feeding at the same time. switch, and then control the stainless steel wire to be fed into the arc at a set speed of 1.8m/min for melting. The wire is fed for a fixed time of 9s at a predetermined arc speed of 10cm/min, and melted to form a soft Cr-Ni stainless steel with a length of 15mm. Additive area. The wires of the two materials are alternately fed into the plasma arc area. After the length of the first single-channel additive reaches 27cm, the arc is extinguished, thereby forming the first ultra-hard iron-based tungsten carbide additive area and soft Cr- Alternating single-pass structure of Ni stainless steel additive area;

(3) The robot controls the welding torch to move the starting point of the adjacent second additive, ignites the arc, and the iron-based tungsten carbide wire is fed into the arc to melt at the same set 1.0m/min, and the wire feeding time is changed to a fixed time On the basis of 18s, the time of mistracking is reduced by 1s, so that the length of the super-hard iron-based tungsten carbide additive channel at the starting end is reduced by 1.7mm; then, the feeding of the iron-based tungsten carbide wire is also controlled by the robot PLC, and the feeding of the stainless steel wire is turned on at the same time. Enter the switch, and then control the stainless steel wire to be fed into the arc at a set speed of 1.8m/min for melting. The wire is fed for a fixed time of 9s at a predetermined arc speed of 10cm/min, and melted to form a soft Cr-Ni with a length of 15mm. Stainless steel additive area; then according to the single-pass additive method in step (2), the iron-based tungsten carbide wire is fed into the arc at a set 1.0m/min for melting, and the wire is fed at a predetermined arc travel speed of 10cm/min For a fixed time of 18s, melt to form a superhard iron-based tungsten carbide additive area with a length of 30mm; this cycle is repeated until the length of the additive channel of 27cm is reached. In the next adjacent third pass of additive welding, the wire feeding time at the starting end of the iron-based tungsten carbide wire is reduced by 2 times the time of staggering (ie 2s) from the fixed time of 18s, and the third pass is formed according to the same rule. A single-pass structure with alternating superhard Fe-based tungsten carbide additive regions and soft Cr-Ni stainless steel additive regions. The feeding time of the starting end of the iron-based tungsten carbide wire for the next adjacent weld bead is reduced from a fixed time of 18s by 3×1s, ₄ ×1s…n×1s according to the number of additive passes, until the time T2 is reduced to Zero, start the cycle again according to the feeding time from the starting end of the iron-based tungsten carbide wire to be 18s, and complete the single-layer addition after 20 additions, thereby forming super-hard iron-based tungsten carbide and soft tungsten carbide in the transverse X direction. The regions of high quality Cr-Ni stainless steel are all regions with alternating distribution structure;

(4) The robot controls the welding torch to move to the starting point of the first additive pass of the first layer, and then raises the same height according to the actual single-layer thickness of 3mm, and then ignites the arc, iron-based tungsten carbide wire and stainless steel wire according to the first layer. The starting end of the second wire feed reduces the staggered time by 1s to start switching, and then alternately feeds and melts the iron-based tungsten carbide wire and stainless steel wire for a fixed time of 18s and 9s, thereby forming the second layer of the first superhard iron base Single-pass structure with alternating tungsten carbide additive areas and soft Cr-Ni stainless steel additive areas; iron-based tungsten carbide at the beginning of adjacent weld passes of the second layer The wire feeding time is successively reduced by 2×1s, 3×1s…(n- ₁ )×1s _, until the T2 time is reduced to zero, and the feeding time of the iron-based tungsten carbide wire at the beginning is 18s again. Cycle again to complete the 2nd layer of additive. Then the 1st lane of each layer is the same as the 2nd lane of the previous layer, and the 2nd lane of each layer is the same as the 3rd lane of the previous layer. , the n-1th lane of each layer is the same as the nth lane of the previous layer, the wire feeding and switching additive method is the same, until the additive parts reach 50cm high, all stop stacking, thus forming a multi-layer longitudinal Y-direction and The superhard iron-based tungsten carbide and soft Cr-Ni stainless steel regions in the vertical Z direction are all alternately distributed structures.

The two alternately melted wires are iron-based tungsten carbide wire and stainless steel wire, the arc heat source is plasma arc, iron-based tungsten carbide wire is a powder core wire with a diameter of 1.6mm, and the mass fraction of tungsten carbide particles is 25%; stainless steel The wire is a solid wire with a diameter of 1.2mm, and the grade is ER308.

The two alternately melted wires are iron-based tungsten carbide wire and stainless steel wire. The wire feeding speed of iron-based tungsten carbide powder core wire is 1.0m/min, and the wire feeding speed of stainless steel wire is 1.8m/min. Single track stacking height.

When the iron-based tungsten carbide wire and the stainless steel wire are added in a single pass, the robot uses the PLC signal to control the wire feeding switch, the arc travel speed is 10cm/min, and the iron _- based tungsten carbide wire feeding time T1 is 18s. _The stainless steel wire is fed for a fixed time T2 of 9s.

Adjacent additive lanes, the feeding time of iron-based tungsten carbide wire at the beginning of the latter lane decreases by 1s in turn.

Adjacent additive layers, the first pass of each layer is the same as the second pass of the previous layer, and the second pass of each layer is the same as the third pass of the previous layer. The n-1th pass is the same as the nth pass of the previous layer.

The average microhardness value of the samples obtained by the additive reached 1432HV, which was significantly improved compared with the 202HV of pure stainless steel; the dynamic yield strength obtained by the Hopkinson bar test reached 1800MPa, which was also obtained compared with 600MPa of pure stainless steel. The impact value is 26KJ, which is also a certain improvement compared to the 5KJ of pure iron-based tungsten carbide.

Example 2

In the multi-dimensional heterostructure of the present invention, a plasma arc is used as a fuse heat source, the additive current set in the additive process is 150A, the ion gas flow rate is 1.0L/min, and the protective gas flow rate is 20L/min.

Combined with Figures 1 to 3, the multi-dimensional heterostructure of superhard iron-based tungsten carbide and soft stainless steel alternately added, superhard iron-based tungsten carbide and soft Cr- The Ni stainless steel regions are distributed alternately.

Multi-dimensional heterogeneous additive structure, in the longitudinal Y direction, the length of the soft Cr-Ni stainless steel region is less than the length of the superhard iron-based tungsten carbide region, the length L1 _of the iron-based tungsten carbide additive region is 45mm, and the Cr-Ni stainless steel increases the length of the region. The length L ₂ of the material area is 15 mm.

In the multi-dimensional heterogeneous additive structure, in the vertical Z direction, the thickness of the soft Cr-Ni stainless steel region is close to that of the superhard iron-based tungsten carbide region, and the thickness δ is 5 mm.

1 to 5, the manufacturing method of the multi-dimensional heterogeneous additive structure includes the following specific steps:

(1) Use a low-temperature heat treatment furnace to heat the stainless steel substrate to 150°C, select the process parameters of additive current, arc travel speed, ion gas flow rate and shielding gas flow rate, and then ignite the arc on the stainless steel substrate;

(2) After igniting the arc, firstly use the robot PLC control signal to turn on the iron-based tungsten carbide wire feeding switch, the iron-based tungsten carbide wire is fed into the arc to melt at the set 3m/min, and the wire travels at the predetermined arc speed. The feeding time of 18 cm/min is fixed for 15s, and it melts to form a super-hard iron-based tungsten carbide additive area with a length of 45mm; then use the robot PLC to control the feeding of iron-based tungsten carbide wire to turn off, and open the stainless steel wire feeding switch at the same time , and then control the stainless steel wire to be fed into the arc at a set speed of 5.3m/min for melting. The wire is fed for a fixed time of 5s at a predetermined arc travel speed of 18cm/min, and melted to form a soft Cr-Ni stainless steel with a length of 15mm. material area. The wires of the two materials are alternately fed into the plasma arc area. After the length of the first single-channel additive reaches 30 cm, the arc is extinguished, thereby forming the first ultra-hard iron-based tungsten carbide additive area and soft Cr- Alternating single-pass structure of Ni stainless steel additive area;

(3) The robot controls the welding torch to move the starting point of the adjacent second additive, ignites the arc, and the iron-based tungsten carbide wire is fed into the arc to melt at the same setting of 3.0m/min, and the wire feeding time is changed to a fixed time On the basis of 18s, the mistracking time was reduced by 1.5s, so that the length of the superhard iron-based tungsten carbide additive channel at the starting end was reduced by 4.5mm; then, the feeding of the iron-based tungsten carbide wire was also controlled by the robot PLC, and the stainless steel wire was opened at the same time. Feed the switch, and then control the stainless steel wire to be fed into the arc at a set speed of 5.3m/min for melting. The wire is fed for a fixed time of 7.5s at a predetermined arc travel speed of 18 cm/min, and melted to form a soft material with a length of 20mm. Cr-Ni stainless steel additive area; then according to the single-pass additive method in step (2), the iron-based tungsten carbide wire is fed into the arc for melting at a set 1.8m/min, and the wire travels at a predetermined arc speed of 18cm/min. The feeding time is 15s, and the superhard iron-based tungsten carbide additive area with a length of 40mm is formed by melting; this cycle is repeated until the length of the additive channel of 30cm is reached. In the next adjacent third pass of additive welding, the wire feeding time at the starting end of the iron-based tungsten carbide wire is reduced by 2 times the time of staggering (ie 3s) from the fixed time of 15s, and the third pass is formed according to the same rule. Single-pass structure with alternating superhard iron-based tungsten carbide additive regions and soft Cr-Ni stainless steel additive regions. The feeding time of the starting end of the iron-based tungsten carbide wire for the next adjacent welds, from a fixed time of 15s, decreases by 3×1.5s, ₄ ×1.5s…n×1.5s according to the number of additive passes, until the time T2 It is reduced to zero, and the cycle starts again according to the feeding time from the starting end of the iron-based tungsten carbide wire to be 15s. After 25 additions are completed, the single-layer addition is completed, thereby forming a super-hard iron-based carbide in the transverse X direction. The regions of tungsten and soft Cr-Ni stainless steel are regions alternately distributed;

(4) The robot controls the welding torch to move to the starting point of the first additive pass of the first layer, and then raises the same height according to the actual single-layer thickness of 5mm, and then ignites the arc, iron-based tungsten carbide wire and stainless steel wire according to the first layer The starting end of the second wire feed reduces the staggered time by 1.5s to start switching, and then alternately feeds and melts the iron-based tungsten carbide wire and stainless steel wire for a fixed time of 15s and 5s to form the second layer of the first superhard iron A single-pass structure in which the base tungsten carbide additive area and the soft Cr-Ni stainless steel additive area alternate; the second layer of the second layer, the second layer of the second layer, the third layer of the second layer, etc., the iron-based carbide at the beginning of the adjacent weld bead of the second layer The feeding time of the tungsten wire material is reduced by 2×1.5s, 3×1.5s…(n- ₁ )×1.5s in turn _, until the time T2 is reduced to zero, and the feeding time of the iron-based tungsten carbide wire at the beginning is re-calculated. For 15s, start the cycle again to complete the second layer of additive. Then the 1st lane of each layer is the same as the 2nd lane of the previous layer, and the 2nd lane of each layer is the same as the 3rd lane of the previous layer. , the n-1th lane of each layer is the same as the nth lane of the previous layer. The wire feed switching additive method is the same, until the additive parts reach 60cm high, all stop stacking, thus forming a multi-layer longitudinal Y-direction and The superhard iron-based tungsten carbide and soft Cr-Ni stainless steel regions in the vertical Z direction are all alternately distributed structures.

The two alternately melted wires are iron-based tungsten carbide wires and stainless steel wires, the arc heat source is plasma arc, iron-based tungsten carbide wires are powder core wires with a diameter of 1.6mm, and the mass fraction of tungsten carbide particles is 40%; stainless steel The wire is a solid wire with a diameter of 1.2mm, and the grade is ER316L.

The two alternately melted wires are iron-based tungsten carbide wire and stainless steel wire. The wire feeding speed of iron-based tungsten carbide powder core wire is 3.0m/min, and the wire feeding speed of stainless steel wire is 5.3m/min. Single track stacking height.

When the iron-based tungsten carbide wire and stainless steel wire are added in a single pass, the robot uses the PLC signal to control the wire feeding switch, the arc travel speed is 18cm/min, and the iron _- based tungsten carbide wire feeding fixed time T1 is 15s. The stainless steel wire is fed for a fixed time T ₂ of 5s.

Adjacent additive lanes, the feeding time of iron-based tungsten carbide wire at the beginning of the latter lane decreases sequentially by 1.5s.

Adjacent additive layers, the first pass of each layer is the same as the second pass of the previous layer, and the second pass of each layer is the same as the third pass of the previous layer. The n-1th pass is the same as the nth pass of the previous layer.

The average microhardness value of the samples obtained by the additive reached 1362HV, which was significantly improved compared with the 196HV of pure stainless steel; the dynamic yield strength obtained by the Hopkinson bar test reached 1640MPa, compared with 630MPa of pure stainless steel. The impact value is 30KJ, which is also improved compared to the 4KJ of pure iron-based tungsten carbide.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. All modifications, substitutions, improvements, etc. made under the principles of the present invention should fall within the protection scope of the present invention.

Claims (7)

1. A manufacturing method of an iron-based tungsten carbide and stainless steel heterogeneous additive structure is characterized in that regions of the additive structure, namely, ultra-hard iron-based tungsten carbide and soft Cr-Ni stainless steel, are distributed alternately in the transverse X direction, the longitudinal Y direction and the vertical Z direction, and comprises the following specific steps:

(1) heating a stainless steel substrate by using a low-temperature heat treatment furnace to reach a preset temperature, selecting technological parameters of additive current, arc advancing speed, ionic gas flow and protective gas flow, and igniting an arc on the stainless steel substrate;

(2) after the electric arc is ignited, firstly, the iron-based tungsten carbide wire is opened by using a PLC control signal of a robot to be fedTurning off the iron-based tungsten carbide wire according to the set wire feeding speed V _f1 Feeding into an arc for melting, the wire advancing at a predetermined arc speed V _w Is fed for a fixed time T ₁ Melt to a length L ₁ A superhard iron-based tungsten carbide additive region; then, the PLC of the robot is used for controlling the feeding of the iron-based tungsten carbide wire to be closed, simultaneously, a stainless steel wire feeding switch is opened, and then, the stainless steel wire is controlled to be at a set speed V _f2 Feeding into an arc for melting, the wire advancing at a predetermined arc speed V _w Is fed for a fixed time T ₂ Melt to a length L ₂ A soft Cr-Ni stainless steel additive area; the wires made of the two materials are circularly and alternately sent into a plasma arc area until the preset 1 st single-channel additive length is reached, and electric arcs are extinguished, so that a single-channel structure with the 1 st longitudinal superhard iron-based tungsten carbide additive area and the soft Cr-Ni stainless steel additive area alternately is formed;

(3) the robot controls the welding gun to move to the starting point of the adjacent 2 nd material increase, the electric arc is ignited, and the iron-based tungsten carbide wire material is fed at the same set wire feeding speed V _f1 The feeding time of the wire is changed into a fixed time T ₁ On the basis of reducing the track crossing time T ₃ So that the length of the superhard iron-based tungsten carbide additive channel at the starting end is reduced by L ₃ (ii) a Then, the PLC of the robot is also used for controlling the feeding of the iron-based tungsten carbide wire to be closed, simultaneously, a stainless steel wire feeding switch is opened, and then, the stainless steel wire is controlled to be at a set speed V _f2 Feeding into an arc for melting, the wire advancing at a predetermined arc speed V _w Is fed for a fixed time T ₂ Melt to a length L ₂ The soft Cr-Ni stainless steel additive area; then according to the single-pass material increase mode in the step (2), the iron-based tungsten carbide wire material is fed at a set wire feeding speed V _f1 Feeding into an arc for melting, the wire advancing at a predetermined arc speed V _w Is fed for a fixed time T ₁ Melt to a length L ₁ A superhard iron-based tungsten carbide additive region; the above steps are circulated until the preset length of the material adding channel is reached; next 3 adjacent additive welding passes, the feeding time of the starting end wire of the iron-based tungsten carbide wire is from the fixed time T ₁ On the basis of reducing 2 times of track crossingM 2T ₃ Forming a 3 rd single-channel superhard iron-based tungsten carbide additive region and a soft Cr-Ni stainless steel additive region in an alternating single-channel structure according to the same rule; the feeding time of the starting end of the iron-based tungsten carbide wire material of the next adjacent welding pass is from a fixed time T ₁ Sequentially reducing by 3T according to the number of additive tracks ₃ ，4T ₃ …nT ₃ Up to T ₁ The time is reduced to zero, and the feeding time from the starting end of the iron-based tungsten carbide wire is T ₁ Circulating again until the size reaches the preset transverse single-layer cladding width, forming a single-channel structure in which an nth super-hard iron-based tungsten carbide additive region and a soft Cr-Ni stainless steel additive region are alternated, and completing single-layer additive so as to form a structure in which the super-hard iron-based tungsten carbide and the soft Cr-Ni stainless steel regions are alternately distributed in the transverse X direction;

(4) the robot controls the welding gun to move to the starting point of the 1 st material increase channel on the 1 st layer, then the welding gun is lifted to the same height according to the actual single-layer thickness delta, then the electric arc is ignited, and the iron-based tungsten carbide wire and the stainless steel wire are fed according to the 2 nd channel on the 1 st layer and the starting end to reduce the channel crossing time T ₃ Starting to switch, and fixing the time T according to the iron-based tungsten carbide wire and the stainless steel wire ₁ And T ₂ The materials are alternately fed and melted in a mode, so that a single-channel structure with the 1 st channel of superhard iron-based tungsten carbide additive regions and the soft Cr-Ni stainless steel additive regions alternately on the 2 nd layer is formed; the feeding time of the iron-based tungsten carbide wire at the adjacent welding bead starting positions of the 2 nd layer, the 3 rd layer and the other second layers is sequentially reduced by 2T ₃ ,3T ₃ …n-1T _3, Up to T ₁ The time is reduced to zero, and the feeding time of the iron-based tungsten carbide wire at the beginning is T again ₁ Circulating again to finish the 2 nd layer material increase; then the 1 st channel of each layer is the same as the 2 nd channel of the previous layer in wire feeding and feeding switching additive mode, the 2 nd channel of each layer is the same as the 3 rd channel of the previous layer in wire feeding and feeding switching additive mode, the n-1 th channel of each layer is the same as the n-th channel of the previous layer in wire feeding and feeding switching additive mode until the preset height of the additive component is formed, and the stacking is stopped completely, so that a plurality of layers of super hard iron-based tungsten carbide and soft Cr-Ni stainless steel areas in the longitudinal Y direction and the vertical Z direction are alternately distributedAnd (5) structure.

2. The manufacturing method of the iron-based tungsten carbide and stainless steel heterogeneous additive structure according to claim 1, wherein the two alternately melted wires are an iron-based tungsten carbide wire and a stainless steel wire, an electric arc heat source is a plasma arc, the iron-based tungsten carbide wire is a flux-cored wire with the diameter of 1.6mm, and the mass fraction of tungsten carbide particles is 25% -50%; the stainless steel wire is a solid wire with the diameter of 1.2mm and the mark is ER308 or ER 316L.

3. The method of manufacturing an iron-based tungsten carbide and stainless steel heterogeneous additive structure according to claim 1, wherein: the two alternately melted wires are iron-based tungsten carbide wire and stainless steel wire, and iron-based tungsten carbide powder core wire is fed with wire V _f1 The speed is 1.0-3.0 m/min, and the stainless steel wire is fed with wire V _f2 The speed is 1.8-5.3 m/min, and the same single-channel stacking height is ensured.

4. The method of manufacturing an iron-based tungsten carbide and stainless steel heterogeneous additive structure according to claim 1, wherein: the robot controls the switch of wire feeding by PLC signal when the iron-based tungsten carbide wire and the stainless steel wire are added in a single channel, and the advancing speed V of the electric arc _w The range is 10-30 cm/min, and the iron-based tungsten carbide wire material is fed for a fixed time T ₁ The range is 5-27 s, the stainless steel wire rod is fed for a fixed time T ₂ The range is 3-15 s.

5. The method of manufacturing an iron-based tungsten carbide and stainless steel heterogeneous additive structure according to claim 1, wherein: the feeding time of the iron-based tungsten carbide wire at the starting position of the next material adding channel and the next material adding channel is reduced sequentially to reduce the channel crossing time T ₃ Time of crossing track T ₃ The range is 1-3 s.

6. The method of manufacturing an iron-based tungsten carbide and stainless steel heterogeneous additive structure according to claim 1, wherein: the 1 st channel of each layer is in the same material increase mode as the 2 nd channel of the previous layer, the 2 nd channel of each layer is in the same material increase mode as the 3 rd channel of the previous layer, and the n-1 th channel of each layer is in the same material increase mode as the nth channel of the previous layer; n is set based on the width in the X direction and the bead width.

7. An iron-based tungsten carbide and stainless steel heterogeneous additive structure prepared based on the manufacturing method of the iron-based tungsten carbide and stainless steel heterogeneous additive structure of any one of claims 1-6, wherein the manufacturing method comprises the following steps: the additive structure is characterized in that regions of the super-hard iron-based tungsten carbide and soft Cr-Ni stainless steel in the transverse X direction, the longitudinal Y direction and the vertical Z direction are alternately distributed; in the longitudinal Y direction of the additive structure, the length of the soft Cr-Ni stainless steel area is less than that of the superhard iron-based tungsten carbide area, and the length L of the iron-based tungsten carbide additive area ₁ 24-45 mm, and the length L of the Cr-Ni stainless steel additive area ₂ 15-25 mm; in the vertical Z direction of the additive structure, the thickness of a soft Cr-Ni stainless steel area is close to that of a superhard iron-based tungsten carbide area, and the thickness delta is 1-5 mm; in the transverse X direction of the additive structure, the width of the soft Cr-Ni stainless steel area is close to that of the superhard iron-based tungsten carbide area, and the width is 5-10 mm; the width of the soft Cr-Ni stainless steel zone is the width of each pass in the additive process.

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