Scarfing

Scarfing eliminates surface and sub-surface defects on steel slabs that are created from steelmaking and continuous casting.

 

• Longitudinal cracks
• Transverse cracks
• Corner cracks
• Star cracks
• Poorly formed oscillation marks
• Pinholes
• Inclusions

 

MultiServ has been scarfing slabs for more than 20 years on sites throughout Europe and USA. The experience and knowledge built up over this time has allowed continuous development and improvement of the technology from manual through to automated scarfing. MultiServ has wide ranging experience of scarfing various different steel grades, including the most demanding steels and their associated defects.

 

The MultiServ Androfer machine is considered the most versatile automated scarfing machine available and is used at sites throughout the world.

 

• Corus - Teesside, UK (1994)
• Arcelor - Sollac Dunkirk, France
• Arcelor - Sollac Florange, France (1992)
• Arcelor - Sidmar Gent, Belgium (1981)
• Mittal Steel - Inland Indiana Harbor, USA (1993)

These customers have recognized the following operational benefits and improvements.

• Improved slab surface quality, fewer rolling mill rejections
• Improvement in through plant yield
• In some cases improvements of 30% and greater have been observed in final product meeting desired specification
• Improved slab dimensional tolerances
• Reduced mill tracking problems, camber and hooking
• Scarfing offers through process improvements
• Significant reductions in steel plant origin defects
• High levels of QA to subsequent processing steps
• Significant reductions in through process rejections (rolling and coating)

 

• Pre 70's Hand Scarfing
• 1979      Flat Androfer
• 1984      MultiForm Scarfing Torch
• 1985      Vertical Slab Position Androfer
• 1990      Fume Enclosure
• 1990      Slab Transfer Cars
• 1994      MultiForm Torch
• 1995      Hot Scarfing
• 1999      ShallowCut Torch
• 2002      Opticon Defect Detection Trials

• Patented system for hot (up to 850^oC) and cold scarfing of slabs
• Versatile robotic control allows operator to mimic hand scarfing
• High productivity scarfing, up to 100,000 tonnes per month
• Operator has perfect view of slab and scarfing area
• Full environmental enclosure to meet toughest EU legislation

• Patented torch design
• Allows variety of scarfing conditions from spot to full face
• Allows variable pass width from 50mm to 350 mm
• Fe powder injection allows clean starts at any point on slab surface

• Developed for the full face skim scarfing of automotive grades
• Utilizes experience gained at SOLLAC Florange with Ti and Ti/Nb SULC steel grades
• Automotive grades
• 1-2% yield loss
• Removing approximately 1mm per pass
• Offers increased productivity, >400 mm pass width
• Gives improved yield, reduced cut depth
• Flatter cut gives improved surface profile

Opticon is an automated system to detect, analyse and report on continuous casting defects.  Defects are visible in the scarfing bath as flashes of light. Experienced Androfer operators can determine type, size and position of defects on slab surface. Filming of the scarfing bath allows image analysis that can be used to gather defect information and has produced the following results.

 

• Ability to differentiate between defects and random fluctuations in background noise
• Acquisition of detailed information on defects
• Type, size, depth, defect removal efficiency
• Detailed information on slab surface
• Number of defects, position

The Androfer and it's SPC Quality System allow high levels of reproducibility. Key performance indicators are record by operator and feed grade including

 

• Yield loss
• Oxygen consumption
• Throughput (tons per hour)
• Product quality
• Peak to trough height

 

Scarfing parameters are continuously monitored and logged and included within the customer's quality program.

 

• Existing operations consistently achieve 94% defect removal
• Standardization of surface quality minimizes defects and improves traceability for resolving quality problems
• Stringent quality demands of customer and end user
• High grade construction products
• Beams, sections and special profiles
• Plate mill feed
• Off-shore applications
• Auto body grades