Continuous casting nozzle assembly for casting of a metallic pipe

Abstract

The invention relates to a continuous casting nozzle assembly (10) for casting, in particular for upward vertical casting, of a metallic, in particular a non-ferrous, pipe, which is suitable for uninterrupted casting, which nozzle assembly comprises a nozzle (11), a mandrel (12) and a cooler (15). Surface roughness of at least part, in particular of the dwindling area (Z), of inner surface of the nozzle (11) of the nozzle assembly (10) is 1-8.0 Ra, advantageously 3-5 Ra.

Claims

1. A continuous casting nozzle assembly for upward vertical casting of a non-ferrous pipe, said assembly being suitable for uninterrupted casting and comprising: a tubular nozzle having a feed end, an outlet end, and an inner surface, a mandrel locating inside the feed end of the tubular nozzle, and a cooler locating around the outlet end of the nozzle and having a cooling liquid space forming a cooling zone, wherein a dwindling area of the inner surface of the nozzle where cast pipe begins to dwindle locates at beginning of the cooling zone and at least part of the dwindling area of an inner surface of the nozzle has a roughness of 3-5 Ra.

2. The continuous casting nozzle assembly according to claim 1, wherein the surface roughness of the inner surface of the nozzle is 3-5 Ra upwards of a point at which a cross-section of a continuously cast pipe begins to dwindle because of casting contraction at the dwindling area located at a point where the cooler begins to have an effect on melt.

3. The continuous casting nozzle assembly according to claim 1, wherein the nozzle includes tangential openings for melt feed in the nozzle, said tangential openings arranged at an upward angle of 0-45.

4. The continuous casting nozzle assembly according to claim 1, wherein the mandrel includes tangential openings for melt feed, said tangential openings arranged at an upward angle of 0-80.

5. The continuous casting nozzle assembly according to claim 4, wherein the nozzle includes tangential openings for melt feed in the nozzle, said tangential openings in the nozzle arranged at an upward angle of 0-45, and wherein the tangential openings in the mandrel have a diameter which is greater than a diameter of the tangential openings in the nozzle.

6. The continuous casting nozzle assembly according to claim 1, wherein the nozzle includes between 2-6 openings for melt feed and that the mandrel includes between 2-6 openings for melt feed.

7. The continuous casting nozzle assembly according to claim 1, wherein the mandrel is conical having an angle of point is between 0.5-3 and wherein the mandrel is tubular with wall thickness of 0.5-10 mm.

8. The continuous casting nozzle assembly according to claim 1, wherein the nozzle is tubular and has a wall thickness of 0.5-4.0 mm.

9. The continuous casting nozzle assembly according to claim 1, wherein the cooler is made of graphite or other ceramic material and wherein the assembly further comprises a cooling zone having a length of 40-400 mm.

10. The continuous casting nozzle assembly according to claim 1, further comprising an isolating part located at bottom of the mandrel.

11. The continuous casting nozzle assembly according to claim 1, wherein the total length of the nozzle is 100-300 mm and the total length of the mandrel is 20-30% less than said total length of the nozzle.

12. The continuous casting nozzle assembly according to claim 1, wherein the nozzle and the cooler have a press-on fit abutment for fastening them to each other and that the nozzle and the mandrel have a press-on fit abutment for fastening them to each other.

13. The continuous casting nozzle assembly according to claim 1, further comprising a protective pot, an isolator and a cooling liquid space.

Description

(1) In the following the invention is described in more detail with reference to the accompanying drawing, in which an advantageous example of the invention is presented in details of which the invention is not to be narrowly limited.

(2) In FIG. 1 is schematically shown in longitudinal side projection one advantageous example of a nozzle assembly according to the invention,

(3) In FIGS. 2A-2D are schematically shown advantageous examples the parts of the nozzle assembly according to FIG. 1.

(4) In the following description with same reference signs are denoted same or corresponding parts or components unless otherwise mentioned.

(5) In the example of FIG. 1 the nozzle assembly 10 comprises a nozzle 11, a mandrel 12, a protective pot 13, an isolator 14, a cooler 15 and a cooling liquid space 16. The nozzle 11 is a tubular part inside of which at the feed end the tubular mandrel 12 for creating the middle opening of the pipe to be casted is located. Around the outlet end of the nozzle 11 the cooler 15 with the cooling liquid space is located thus forming the cooling zone. At the beginning of the cooling zone the dwindling area Z at which the cross-section of a continuously cast pipe begins to dwindle because of casting contraction is located. According to the invention advantageously at least the dwindling area Z of the inner surface of the nozzle 11 of the nozzle assembly 10 has a surface roughness of 1-8.0 Ra, advantageously of 3-5 Ra. Around the cooler 15 the isolator 14 is located around which the protective pot 16 is located. Another isolating part 17 is located at the bottom of the mandrel 12. In the example of FIG. 2A in the longitudinal side projection the nozzle 11 and the mandrel 12 of the nozzle assembly are shown. The nozzle 11 comprises openings 21 for melt feed and the mandrel 12 comprises openings 22 for the melt feed. At the bottom of the mandrel 12 the isolating part 17 is located. In the example of FIG. 2B in the longitudinal side projection the nozzle 11 is shown. The total length L11 of the nozzle 11 is 100-300 mm, advantageously 170 mm. The total length L12 of the mandrel 12 is advantageously 20-30% less than the length L11 of the nozzle 11. As shown in FIGS. 2A-2B the openings 21 for melt feed in the nozzle 11 of the nozzle assembly 10 are in an upward angle of 0-45, advantageously 10-20 and the openings 22 for melt feed in the mandrel 12 of the nozzle assembly 10 are in an upward angle of 0-80, advantageously 10-20. At the beginning of the cooling zone of the nozzle 11 the dwindling area Z at which the cross-section of a continuously cast pipe begins to dwindle because of casting contraction is located and the surface roughness of the dwindling area Z is 1-8.0 Ra, advantageously of 3-5 Ra. In the examples of FIGS. 2C-2D cross-sectional end projections are shown of the nozzle 11 and the mandrel 12 and the openings 21, 22 for melt feed in the nozzle 11 and in the mandrel 12 are tangential. The diameter D22 of the openings 22 for melt feed in the mandrel 12 is greater than the diameter D21 of the openings 21 for melt feed in the nozzle 11, advantageously the diameter D22 of the openings 22 for melt feed in the mandrel 12 is 10-100% greater, most advantageously 0.5 mm greater. The diameter D21 of the openings 21 for melt feed in the nozzle 11 is advantageously 1.0-5.0 mm and the diameter D22 of the openings 22 for melt feed in the mandrel 12 is advantageously 1.1-10.0 mm. In the nozzle 11 there are 2-6, advantageously 3 openings 21 for melt feed and in the mandrel 12 there are 2-6, advantageously 3 openings 22 for melt feed. In the nozzle assembly 10 the nozzle 11 and the cooler 15 have a press-on fit abutment for fastening them to each other. Also the nozzle 11 and the mandrel 12 have a press-on fit abutment for fastening them to each other. To ensure the abutment between the nozzle 11 and the mandrel 12a locking pin 25 may be provided. The mandrel 12 is conical and its angle of point is 0.5-3, advantageously 2. The nozzle 11 is tubular and the thickness of the wall in the cooling zone is 0.5-4.0 mm, more advantageously 1.0-2.0 mm. The conical mandrel 12 is tubular and thickness of the wall is 0.5-10 mm, more advantageously 2-4 mm. According to an advantageous feature the cooler 15 of the nozzle assembly 10 is made of graphite or other ceramic material and the cooling zone has length of 40-400 mm, advantageously 80 mm.

REFERENCE SIGNS USED IN THE DRAWING

(6) 10 nozzle assembly 11 nozzle 12 mandrel 13 protective pot 14 isolator 15 cooler 16 cooling liquid space Z dwindling area