Process for horizontally extruding cupronickel pipe

Abstract

The invention provides a process for horizontally extruding a cupronickel pipe, and relates to the technical field of cupronickel alloy pipes, the process comprises the following steps: S1, weighing raw materials according to the components of the cupronickel pipe, adding the raw materials into a smelting furnace, and casting to obtain a solid cupronickel ingot blank; s2, the solid white copper ingot blank is cut off to obtain a cut-off ingot blank; s3, the cut ingot blank is heated and subjected to heat preservation, and a pipe blank is obtained; s4, the pipe blank is extruded on an extruding machine, and a hollow pipe blank is obtained; and S5, the hollow pipe blank is subjected to wall thickness detection, and the cupronickel pipe is obtained after the hollow pipe blank is detected to be qualified. According to the process for horizontally extruding the cupronickel pipe, the thermal deformation resistance is reduced through scientific design and control of alloy elements and impurity elements; stepless power regulation power frequency induction heating is adopted, the temperatures of the inner surface and the outer surface of a cast ingot are uniform, the fluidity of metal in the extrusion process is improved, and the problem that the wall thickness of an extruded pipe blank is not uniform is greatly solved by combining the length of a cut ingot blank and reasonable setting of extrusion parameters.

Description

Technical Field

[0001] The invention relates to the technical field of white copper alloy tubes, in particular to a process for horizontally extruding white copper tubes. Background Art

[0002] Copper-nickel alloy has excellent mechanical properties, welding properties, corrosion resistance and resistance to biological contamination. It is widely used in marine engineering, ocean-going ships, deep-sea ships, petrochemicals and other fields. It is often used in seawater pipelines, tube sheets, condensers and heat exchange tubes. B30 series copper-nickel alloy pipes are one of the widely used products. Due to the high alloy composition of BFe30-1-1, the deformation resistance is increased and hot processing is difficult.

[0003] The horizontal extruder is a transverse structure parallel to the ground. It is used in an absolute number of applications in the domestic copper tube industry due to its advantages such as high production efficiency, energy saving and environmental protection, and flexible equipment layout. However, during the production process of the horizontal copper extruder, due to the wear and deformation of the equipment's motion device and the change of position, the hot ingot is in an unstable state during the extrusion process, the force center is offset, eccentricity occurs, and the wall thickness of the tube is uneven, making it difficult to maintain accuracy. Some parts change their correct position due to thermal expansion, causing the center to be misaligned, resulting in eccentricity of the copper tube billet, that is, uneven wall thickness. Uneven wall thickness is an inherent problem of the horizontal extruder in the production of copper tube billets, which brings difficulties to the dimensional accuracy control of the copper tube. At present, the domestic basic production process regulation is used to solve the problem, which is a temporary solution and does not address the root cause, affecting the continuous production of products. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a process for horizontally extruding white copper tubes, which solves the inherent problem of uneven wall thickness of BFe30-1-1 white copper tubes produced by an extruder without affecting production efficiency, and the wall thickness tolerance reaches ±0.6mm.

[0005] The technical solution adopted by the present invention is: A process for horizontally extruding a white copper tube, comprising the following steps: Step S1. The nickel silver tube comprises the following components by mass percentage: Ni 29.00-29.30 wt%, Mn 0.50-0.55 wt%, Fe 0.50-0.55 wt%, C≤0.03 wt%, Cu content of 69.30-70.00 wt%; the rest are inevitable impurities, and the total content of inevitable impurities is ≤0.30 wt%. Raw materials are weighed according to the above components, and the raw materials are added into a smelting furnace, covered with charcoal, and then melted and cast to obtain a solid nickel silver ingot; Step S2. Cutting the solid white copper ingot obtained in step S1 to obtain a cut ingot; Step S3. heating and keeping the cut ingot obtained in step S2 to obtain a tube; Step S4. Extruding the tube blank obtained in step S3 on an extruder to obtain a hollow tube blank; Step S5. Perform a wall thickness test on the hollow tube blank obtained in step S4, and obtain a white copper tube after the test is qualified.

[0006] Preferably, in the process of horizontally extruding the white copper tube, the melting and casting temperature in step S1 is 1340°C to 1400°C.

[0007] Preferably, in the process for horizontally extruding a nickel silver tube, the solid nickel silver ingot is cut into a length of Φ200-210 mm in step S2.

[0008] Preferably, in the process of horizontal extrusion of white copper tube, the heating temperature in step S3 is 1040-1060° C. and the holding time is 15-25 min.

[0009] Preferably, in the process of horizontally extruding the white copper tube, the extrusion speed in step S4 is 8-10 mm / s, and the extrusion pressure is 160-180 kgf.

[0010] Preferably, in the process of horizontally extruding the white copper tube, the piercing force of the extrusion in step S4 is 100-120 kgf.

[0011] Preferably, in the process of horizontally extruding a white copper tube, the diameter of the hollow tube blank in step S4 is Φ84-85 mm, and the wall thickness is 10-11 mm.

[0012] Preferably, in the process of horizontally extruding the white copper tube, the wall thickness tolerance is controlled to be ±0.6 mm in step S5.

[0013] Advantages of the present invention: (1) The process of horizontal extrusion of white copper tubes of the present invention solves the inherent problem of uneven wall thickness of BFe30-1-1 white copper tubes produced by an extruder without affecting production efficiency, and the wall thickness tolerance reaches ±0.6 mm.

[0014] (2) The process of horizontal extrusion of white copper tube of the present invention reduces the resistance to thermal deformation through scientific design and control of alloy elements and impurity elements; adopts stepless power regulation frequency induction heating to make the temperature of the inner and outer surfaces of the ingot uniform, improves the fluidity of the metal during the extrusion process, and combines the reasonable setting of the ingot cutting length and extrusion parameters to greatly improve the problem of uneven wall thickness of the extruded tube. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments.

[0016] Example 1 A process for horizontally extruding a BFe30-1-1 white copper tube comprises the following steps: Step S1. The nickel silver tube comprises the following components by mass percentage: Ni 29.06wt%, Mn 0.52wt%, Fe0.51wt%, C 0.015wt%, Cu 69.729wt%; the rest are inevitable impurities, and the total content of inevitable impurities is 0.166wt%. Electrolytic copper, electrolytic nickel, iron, manganese, and magnesium-copper alloy raw materials are weighed according to the above components, and the raw materials are added to a smelting furnace, covered with charcoal, and then cast to obtain a Φ180mm solid nickel silver ingot, and the casting temperature is 1346°C; Step S2. Cutting the solid white copper ingot obtained in step S1 into a length of Φ200 mm to obtain a cut ingot; Step S3. The cut ingot obtained in step S2 is subjected to stepless power modulation power frequency induction heating and heat preservation, the heating temperature is 1040°C, the heat preservation time is 15min, and a tube is obtained; Step S4. The tube blank obtained in step S3 is extruded on an extruder at an extrusion speed of 8 mm / s, an extrusion pressure of 160 kgf, and an extrusion piercing force of 100 kgf to obtain a hollow tube blank with a diameter of Φ84 mm and a wall thickness of 10 mm; Step S5. The hollow tube blank obtained in step S4 is subjected to wall thickness detection, the wall thickness tolerance is -0.16~+0.32mm, the wall thickness uniformity is good, and a qualified BFe30-1-1 white copper tube is obtained.

[0017] Example 2 A process for horizontally extruding a BFe30-1-1 white copper tube comprises the following steps: Step S1. In terms of mass percentage, the nickel silver tube includes the following components: Ni 29.22 wt%, Mn 0.53 wt%, Fe0.53 wt%, C 0.012 wt%, Cu 69.495 wt%; the rest are inevitable impurities, and the total content of inevitable impurities is 0.213 wt%. According to the above components, raw materials of electrolytic copper, electrolytic nickel, iron, manganese, and magnesium-copper alloy are weighed, and the raw materials are added to a smelting furnace, covered with charcoal, and then cast to obtain a Φ180 mm solid nickel silver ingot, and the casting temperature is 1360 ° C; Step S2. Cut the solid white copper ingot obtained in step S1 into a length of Φ205 mm to obtain a cut ingot; Step S3. The cut ingot obtained in step S2 is subjected to stepless power modulation power frequency induction heating and heat preservation, the heating temperature is 1050°C, the heat preservation time is 20min, and a tube is obtained; Step S4. The tube blank obtained in step S3 is extruded on an extruder at an extrusion speed of 9 mm / s, an extrusion pressure of 170 kgf, and an extrusion piercing force of 110 kgf to obtain a hollow tube blank with a diameter of Φ84.5 mm and a wall thickness of 10.5 mm.

[0018] Step S5. The hollow tube blank obtained in step S4 is subjected to wall thickness detection, the wall thickness tolerance is -0.32~+0.45mm, the wall thickness uniformity is good, and a qualified BFe30-1-1 white copper tube is obtained.

[0019] Example 3 A process for horizontally extruding a BFe30-1-1 white copper tube comprises the following steps: Step S1. The nickel silver tube comprises the following components by mass percentage: Ni 29.28wt%, Mn 0.52wt%, Fe0.55wt%, C 0.008wt%, Cu 69.452wt%; the rest are inevitable impurities, and the total content of inevitable impurities is 0.19wt%. Electrolytic copper, electrolytic nickel, iron, manganese, and magnesium-copper alloy raw materials are weighed according to the above components, and the raw materials are added to a smelting furnace, covered with charcoal, and then cast to obtain a Φ180mm solid nickel silver ingot, and the casting temperature is 1375°C; Step S2. Cut the solid white copper ingot obtained in step S1 into a length of Φ210 mm to obtain a cut ingot; Step S3. The cut ingot obtained in step S2 is subjected to stepless power modulation power frequency induction heating and heat preservation, the heating temperature is 1060°C, the heat preservation time is 25min, and a tube is obtained; Step S4. The tube blank obtained in step S3 is extruded on an extruder at an extrusion speed of 10 mm / s, an extrusion pressure of 80 kgf, and an extrusion piercing force of 120 kgf to obtain a hollow tube blank with a diameter of 85 mm and a wall thickness of 11 mm.

[0020] Step S5. The hollow tube blank obtained in step S4 is subjected to wall thickness detection, the wall thickness tolerance is -0.29~+0.51mm, the wall thickness uniformity is good, and a qualified BFe30-1-1 white copper tube is obtained.

[0021] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A process for horizontally extruding a white copper tube, characterized in that: The following steps are involved: Step S1. The nickel silver tube comprises the following components by mass percentage: Ni 29.00-29.30 wt%, Mn 0.50-0.55 wt%, Fe 0.50-0.55 wt%, C≤0.03 wt%, Cu 69.30-70.00 wt%; the rest are inevitable impurities, and the total content of inevitable impurities is ≤0.30 wt%. Raw materials are weighed according to the above components, and the raw materials are added into a smelting furnace, covered with charcoal, and then melted and cast to obtain a solid nickel silver ingot; Step S2. Cutting the solid white copper ingot obtained in step S1 to obtain a cut ingot; Step S3. heating and keeping the cut ingot obtained in step S2 to obtain a tube; Step S4. Extruding the tube blank obtained in step S3 on an extruder to obtain a hollow tube blank; Step S5. Perform a wall thickness test on the hollow tube blank obtained in step S4, and obtain a white copper tube after the test is qualified.

2. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: The melting and casting temperature in step S1 is 1340°C to 1400°C.

3. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: In step S2, the solid nickel silver ingot is cut into a length of Φ200-210 mm.

4. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: In step S3, the heating temperature is 1040-1060° C., and the insulation time is 15-25 min.

5. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: In step S4, the extrusion speed is 8-10 mm / s, and the extrusion pressure is 160-180 kgf.

6. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: The punching force of the extrusion in step S4 is 100-120 Kgf.

7. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: In step S4, the diameter of the hollow tube blank is Φ84-85 mm, and the wall thickness is 10-11 mm.

8. The process for horizontally extruding a white copper tube according to claim 1, characterized in that: In step S5, the wall thickness tolerance is controlled to be ±0.6 mm.