Flux cored wires types
Primary Goods
Powdred wires manufacturing scheme
Quality control and packaging
List of objects for surfacing

Flux cored wires types

The manufacturing technique for production of alloyed wire and high-alloyed wire of solid cross-section is an expensive and complicated process, which only large industrial complexes and hardware plants are capable to perform, as wire-dragging technique with small-scale cogging and repeated intermediate annealing is time and funds consuming.

The manufacturing of high-alloyed electrode medium for mechanized build-up welding could be relatively simply performed with the help of powdered wire consisting of the casing (soft steel, nickel or similar tape) and the core made of alloying components powders (ferroalloys, pure metals, carbides, borides etc.). In self-protected powdered wires, using of which do not require fusing agents or shielding gases, the powdered wire core working mixture includes gas and slag-forming components, deoxidizers and elements possessing great chemical similarity with nitrogen. In such case the buil-up welding could be performed without fusing agents and shielding gas. Such wire is called self-protected. There have been developed and are used:

- with fusing agent;
- in the environment of shielding gases;
- with open arch in air.

The powdered wires with the diameter of 3.6 mm for build-up welding with fusing agents and of 2.0 – 3.0 mm for open arch welding are used most often. For large dimension parts build-up welding with fusing agent the wire of 5.0 – 6.0 mm is used.
 

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There have been developed many designs of powdered wires (Figure 1.), but for the buil-up welding operations the design in the form of simple tube with compact juncture (a) and with overlapped juncture (b) occurred to be the most simple and suitable. The manufacturing method of welding and buil-up powdered wires is practically identical.

The main way of powdered wire manufacturing is tape forming and filling of semimanufactured article with working mixture in special device with further wire-dragging.

Primary Goods

Powdered wire consists of casing and core (filling agent). Cold rolled tape of low-carbon still, non-polished and extremely soft, serves as a casing. The requirements to this tape are stipulated in GOST 503-71 State Standards.

The dimensions of the tape with regard to thickness and width are determined by wire manufacturing technique for the wire of predetermined diameter. The basic attributes of the mechanic properties of the tape are as follows: temporary tensile strength 28 – 40 kg/mm2; relative tensile strain – not less than 30%.

The material of the tape is steel 08 kilogram-weight with the following chemical composition (GOST 1050 – 60): 0.05 – 0.11% C; 0.25 – 0.50% Mn; not more than 0.03% Si; not more than 0.040% S and P.

The tape is supplied in rolls or rounds with the inside diameter not less than 150 mm. Its surface is coated with protective lubrication.

The tape dimensions to manufacture the wire with predetermined diameter can be accepted in accordance with the data of experienced manufacturer or found by own calculations.

Supplied tape is cleaned from lubricant and dirt prior to the manufacturing process. There exist two methods of cleaning: mechanical and chemical using ultrasound. The mechanical method is done by passing the tape through special drums with Vienna lime carbonate and get degreased.

Working mass serves as a core of powdered wire. Working mass components have to comply with the respective requirements with regard to its chemical composition and granulation. Working mass powders’ grains size determines looseness of the later, and, respectively, the quality of proportioning when filling the wire.

Some materials are supplied in the form of powders with granulometric composition close to the required. Therefore, such materials undergo only controlling screen fines and drying, if necessary, prior to being used in wire manufacturing. Rutile concentrate, fluorite concentrate, starch, alumina, ferrite powder, silicofluoric natrium and number of other materials are supplied in the form of powder.

The materials supplied in lumps undergo crushing and grinding (if necessary, they also undergo drying and glowing). It is convenient to carry out the grinding of the materials at the grinding machines with continuous screening of the product, which provides for high output of the valid material. The ready powders are weighed out in accordance with the compounding and undergo dry mixing.

The finished mixture is delivered to the wire filling shop. In case of need the mixture may be kept in sealed containers.

POWDERED WIRES MANUFACTURING SCHEME

1. Unwinding device. Designed for unwinding and feeding of the tape into the welding machine.

2. Welding machine. Designed for providing continuity of the dragging process by way of butt fusion welding or contact welding of the tape edges. 

3. Forming device. It provides for tape forming into tubulated profile by means of several pairs of rollers (usually not more than 12), with preliminary working mass portioning into the given profile of formed tape.

4. Drawbench. Designed for further dragging of semimanufactured article filled with working mass with the help of drums (6-12 pieces) until necessary diameter of the wire is reached.

5. Powdered wire takeoff device. Designed for takeoff of ready wire with subsequent loading at a jig to tie into bundles.

 

Quality control and packaging

Ready powdered wire is tested and undergo acceptance procedure in compliance with the developed technical specification. The acceptance of the wire is performed in batches. A batch consists of bundles manufactured of materials of the same composition with permanent calculated composition of powdery core. The weight of the batch is from 2,000 to 10,000 kg. All bundles are checked for their appearance, accuracy of winding, diameter of bundle and diameter of wire.

The surface of the wire has to be clean. The presence of rust on the surface and in its cores well as the grease in the core is not tolerated. The presence of marks and traces of grease from dragging on the surface of the tape shall net be considered a reason for rejection. The inside diameter of a bundle is no more than 350 mm, the weight of a bundle is no less than 3 kg and no more than 60 kg. A wire in a bundle must be one piece of wire without ruptures. The entanglement of wire in a bundle is not tolerated.

The surveillance is executed by Technical Control Department.

The CSPF “Elna” products correspond to highest requirements with regard to its quality of manufacturing as well as its packaging quality.

The packaging of the finished products is performed in strict compliance with the State Standards (GOST). Bundles of wire with the total weight of 55-80 kg are packed with dense polyethylene with selicogel and put into metal barrels with diameter of 350 mm and 60 cm high.

At the request of a customer the wire with the weight higher than 10 kg is wound on spools.

List of objects for surfacing

Typical objects for buil-up welding operations:

- ships’ engines piston crowns;
- boring and oil drilling equipment parts;
- beltlines;
- cutters for cold and hot cutting;
- grainer pan bowls;
- metallic forms;
- gear cogs;
- rollers for metal blocks continuous molding machines;
- pumping equipment;
- mining equipment parts;
- concrete mixer blades;
- axes, springs and wheels of railway carriages;
- pilger bowls of tube mills;
- propeller shafts of ships;
- crossbars of points and crossings;
- straightedges of piercing mills;
- parts of sintering equipment;
- parts of blast furnaces etc.