A control method for internal defects in the production of wire rod for welding wire

A control method and internal defect technology, applied in welding equipment, manufacturing tools, welding media, etc., can solve the problem of reducing the plasticity, cracks, folding, looseness, and internal defects of the steel used for welding wire, that is, the wire rod steel used for welding wire. and other problems to achieve the effect of reducing thermal stress cracks

Active Publication Date: 2021-10-15
JIANGSU YONGGANG GROUP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the smelting and production process of P91 welding wire steel, due to the easy precipitation of alloys and carbides, the plasticity of the steel for welding wire, that is, the wire rod steel for welding wire, is reduced, and the inner and surface of the wire rod steel for welding wire are prone to cracks, folds, and looseness. and other defects
However, it is very difficult to control the internal defects of wire rod steel for welding wire in the production process.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] In the die-casting step of this embodiment, the shape of the die-cast ingot is a square ingot, the temperature of molten iron for die-casting is 1563°C, the casting time for the ingot body is 6min, the casting time for the cap mouth is 5min, and the time for drawing the mold is 4h; t Add heating agent, add carbonized rice husk at 0.95Kg / t; 1.5 hours after demoulding, put the molded ingot into the heat preservation cover, and the ingot is treated by heat delivery. The exothermic agent insulates the molten steel, thereby prolonging the solidification time of the molten steel in the riser, reflowing and recasting, and realizing feeding; the carbonized rice husk mainly plays the role of heat preservation.

[0036] The ingot is hot sent to the heating furnace for 45 minutes; the heating temperature is 775°C, kept for 2h, heated at a heating rate of 90°C / h for 6h, and finally kept at 1255°C for 19h. Putting the molded ingot into the heat preservation cover and adopting the ho...

Embodiment 2

[0047] In the die-casting step of this embodiment, the shape of the die-cast ingot is a square ingot, the temperature of the molten iron for die-casting is 1565°C, the casting time for the ingot body is 7min, the casting time for the cap mouth is 7min, and the time for drawing the mold is 5h; tAdd heating agent, add carbonized rice husk at a rate of 1.0Kg / t; 1.2h after demoulding, put the molded ingot into the heat preservation cover, and the ingot is treated by heat delivery.

[0048] Heat the ingot to the heating furnace, and the time is controlled for 43 minutes; the heating temperature is 780°C, the heat preservation is 2.5h, the heating rate is 100°C / h for 5.5h, and finally the heat preservation is 17h at 1260°C;

[0049] In the process of billet opening and initial rolling, the middle billet is cut with a length of 255mm; the tail riser is cut with a length of 1250mm;

[0050] Hot charging annealing: the blooming billet is collected at a temperature of 550°C and sent int...

Embodiment 3

[0058] In this example, the mold-cast ingot shape is a square ingot, the molten iron temperature of the ingot is 1567°C, the casting time for the ingot body is 9 minutes, the casting time for the cap mouth is 9 minutes, and the drawing time is 3 hours; Add carbonized rice husk at 0.98Kg / t; put the molded ingot into the heat preservation cover 1.7h after the start of demoulding, and the ingot is treated by heat delivery.

[0059] Heat the ingot to the heating furnace for 42 minutes; heating temperature is 785°C, heat preservation for 3 hours, heating at a heating rate of 120°C / h for 4 hours, and finally heat preservation at 1260°C for 18 hours; after the above-mentioned mold casting, the ingot is immediately loaded In the heat preservation cover and sent to the heating furnace by heat treatment, the ingot is always in a state of heat preservation during transportation, and cracks and internal defects will not occur due to excessive heat loss. In the process of blanking and init...

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Abstract

The invention discloses a method for controlling internal defects in the production of wire rods for welding wires and wire rods for welding wires. The preparation method includes hot delivery of die-cast ingots and steel ingots, heating of rolled steel ingots, rough rolling, slow Cooling and annealing, finishing, heating the billet for wire rod rolling, opening and finishing rolling, reducing and sizing, wire rod shelter from wind and stack cooling and complete covering heat preservation, and annealing treatment for the finished wire rod; The finished wire rod for welding wire produced by the invention has a crack depth of less than 0.03mm, no segregation, a tensile strength of 599-650MPa, a yield strength of 371-401MPa, a reduction of area of ​​more than 75%, and an elongation of more than 24%. The whole production process of the invention is carried out in a reasonable heat preservation process, which reduces the occurrence of thermal stress cracks or other defects in the production process of the wire rod.

Description

technical field [0001] The invention belongs to the technical field of welding materials, in particular to a method for controlling internal defects in the production of wire rods for welding wires. Background technique [0002] P91 welding wire is the supporting gas-shielded welding wire for P91 steel, which is equivalent to the standard model ER62-B9 of the national standard GB / T 8110-2008, and the standard model ER90S-B9 of the American standard AWS A5.28:2005; it can be used in a variety of protective gas atmospheres Excellent mechanical properties and process performance are obtained. It is mainly used in the welding of superheaters, re-superheaters, main steam pipes and other parts of ultra-supercritical thermal power units, and the operating temperature exceeds 600 °C. [0003] At present, the stock of domestic P91 pipe market is about 150,000 tons / year, and its welding wire consumption is about 2% of that of P91 pipes, and the domestic demand is about 3,000 tons / yea...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): B23K35/40
CPCB23K35/40
Inventor张刘瑜郭峰赵亚平李刚屈小波杜龑王鲁义李超
OwnerJIANGSU YONGGANG GROUP CO LTD