FCAW (Flux Cored Arc Welding)

1. What is hardfacing?

Metal parts often fail their intended use not because they fracture, but because they wear, which causes them to lose dimension and functionality. Hardfacing, also known as hardsurfacing, is the application of buildup or wear-resistant weld metals to a part's surface by means of welding or joining.

BENEFITS OF HARDFACING:

2. What base metals can be hardfaced?

Carbon and low-alloy steels with carbon contents of less than 1 percent can be hardfaced. High-carbon alloys may require a special buffer layer.

The following base metals can be hardfaced:

FCAW and GMAW may be interchangeable or the same in terms of popularity. However, the trend is toward use of semiautomatic and automatic welding procedures.

TYPES OF WEAR CONDITIONS HARDFACING CAN REDUCE OR ELIMINATE:

Abrasive wear is caused by foreign materials rubbing against a metal part.

Metal-to-metal wear results from non-lubricated friction of metal parts. As metal surfaces slide against each other, the high areas are broken and tiny fragments of metal are torn away.

A blow or a series of blows to a surface resulting in fracture or gradual deterioration. In general, impact resistance
decreases as carbide content is increased. Because abrasion resistance increases with carbide content, a compromise often must be made.

Heat influences wear resistance by:

The deterioration of metal by chemical or electrochemical reaction with its environment.

Wear in which loss of material occurs due to the cutting action of moving particles carried in a fluid stream is termed impingement erosion. At low impingement angles (<15%), hardfacing with large amounts of carbides (hypereutectic alloys), are recommended. At high impingement angles (>80%), large amounts of text-small-link (hypoeuctectic alloys), are recommended.

Material loss due to very-small-amplitude vibrations at mechanical connections, such as riveted joints. This type of wear is a combination of oxidation and abrasive wear

3.What is the Deposition Rate of different welding processes?

Note: It can be seen that FCAW has highest deposition rate among all common processes.

Hardfacing in Process

Hardfacing in Process

Category Process Arc welding Flux core arc welding (FCAW) Gas metal arc welding (GMAW) Gas tungsten arc welding (GTAW) Plasma arc welding (PAW) Shielded metal arc welding (SMAW) Submerged arc welding (SAW) Torch welding Oxy/fuel gas welding (OFW) Other welding Electron beam welding (EBW) Electroslag welding (ESW) Furnace braze (FB) Laser beam welding (LBW)

Common Materials Used in Hardfacings
Hardfacings are good for substrate materials that are suitable for welding, such as low-carbon steel. The most common hardfacing materials are nickel alloys and iron/chromium alloys used in wear resistance and high stress abrasion. Common materials for hardfacing are listed as follows:

APPLICATIONS
FCAW is used for all Overlaying, Hardfacing & Cladding applications.

Typical application areas of the FCAW technology are extruding machine screws, valves, valve seats of internal combustion engines (motorcar, marine, locomotive etc.), accessories for ships, petroleum chemistry and power generation, cutting tools (milling cutters, broaches, knifes) ,Equipment for mining, crushing, rolling, road building and tunneling, Process equipment in ceramics and cement production,Molds and forging dies, Pulp and paper industry equipment, Agricultural equipment, parts for nuclear plants, parts for chemical plant

Advantages of FCAW

1. It is a process which can be very easily automated to the highest degree, as compare to any other welding process.
2. Deposition efficiency & deposition speed is very high.
3. It has got very high electrical efficiency (low heat input)
4. FCAW uses spray transfer for deposition of metal to job
5. All the above results in a very low deformation in the job.
6. It is possible to add alloys through the core (flux) to give the final desire composition.
7. It is possible to work on site / out doors.

Finished Bead

Specifications of Power Source (CV)

Model ACW 250 300 400 500 600 Input Volts 380-440, 3Ø, 50Hz 380-440, 3Ø, 50Hz 380-440, 3Ø, 50Hz 380-440, 3Ø, 50Hz 380-440, 3Ø, 50Hz Output Rating 250A 300A 400A 500A 600A OCV 18-44V 18-44V 18-52V 18-56V 18-60V Duty cycle 70% 70% 70% 70% 70% KVA 10 14 18 24 34 Cooling Forced Air Forced Air Forced Air Forced Air Forced Air Insulation Class H H H H H Permissible Wire Ø in mm 0.8-1.2 0.8-1.2 0.8-1.6 0.8-1.6 0.8-2.4 Overall Dimensions (approx) in mm Length mm 685 685 685 740 740 Width mm 590 590 590 640 640 Height mm 930 930 930 1030 1030 weight (Kg) 190 205 230 300 325 wire speed - 0 to14 meters per minute

Welding Gun
Suitable Welding Gun will be provided as per requirement of the customer. Standard Guns available are 250 A / 400 A / 600 A in Gas Cooled / Water Cooled models.

Oscillator
Oscillator with column & boom suitable for the above positioner
With variable speed potential control along with micro slide
With PMDC motors & Electronic Solid state Drives.

Wire Feeder
The feed mechanism is robust, light in weight for easy manoeuvrability maintenance free, and has drive system totally enclosed in alloy steel casing with hardened rollers, with interchangeability to choose different wire diameters, pre-flow and post-flow to eliminate contamination of weld. Electronic stepless control with feed back system for constant output speed and quality welding, push buttons for inching and gas checking. Quick release device for easy change over of insulated spool holder.

Controller
Programmable Logic Control (PLC) with 4 Input and 8 Output to control Power Source, Positioner, Oscillator & Wire feeder, Water Recirculator Cum Chiller
Housed in a seperate Control Panel

Welding Turntable

Welding Positioner

Tank Rotators

Column and Boom ( manupilators )

Welding Lathe

Water coolers for water cooled torches

Welding Automation