daniel lenane & filko bravcevic - veem limited - centrifugally cast, metallurgically bonded 28%...
TRANSCRIPT
Overview
VEEM Limited
The Journey - Research and Development
Duo Metal - What is it?
Product characteristics
Product form and range
Case study
VEEM Limited – Who are we? Western Australian Privately owned listed company
established in 1968
Employs 170 staff to supply manufactured components
into a variety of markets
Specialist wear products
Custom foundry products in Copper, Ferrous, Nickel and
Cobalt based alloys
Valves and components for Australian submarines
Marine equipment – Propulsion, ride control Gyrostabilisers
General engineering services
The Project ObjectiveTo Develop a unique pipe spool system to be used for
industrial process flow of abrasive and corrosive material;
Operating temperatures up to 175oC
Operating pressures up to 2500kPA
Ability to Ultrasonically test remaining wear material in situ
Achieve a target service life of 62 weeks or more
Integrate with existing pipe work internal diameters and
configuration
Be readily fabricated to spools, tee’s, reducers and crosses
Conform to recognised standards
The Key Challenges Obtaining a metallurgical bond between two very
dissimilar metals without;
Delaminating of the two materials at the transition zone
Creating a poorly defined transition between the alloys
Hot tearing of the outer steel layer during production
Controlling the process temperature and timing
Heat treatment processes simultaneously compatible
Weld procedures and sizing strategies for compatibility to
existing pipe systems
Centrifugally cast dissimilar metals into one pipe;
Metallurgical bond between material layers > 95% total area
bonded
High strength outer shell ASTM A216 – Alloy WCB
High wear resistant inner layer –AS 2027 / Cr 27
Ability to UT inspect for remaining wear material in situ
Able to vary OD and ID to suit application
Can be fabricated for pressure containing parts
Able to match Nominal bore to equivalent nominal bore
What is Duo Metal ?
Centrifugal Casting Approach
Chill casting process creates primary carbides oriented
perpendicular to bore axis
Material integrity
Grain size is finer than equivalent static sand cast method
Rapid chilling from OD drives solidification directionally
toward the bore avoiding formation of centreline shrinkage
Centrifugal forces accelerate separation of impurities to the
internal bore
Grains have same alignments for full length of pipe
Key Characteristics
The Bond
EDS and SEM
EDS and SEM
EDS and SEM
Key Characteristics
Straight Spools Currently nominal bores from 80NB up to 550NB
Tee’s and Crosses Nominal Bores Pipe
Nominal Bore Tee or Cross
Trial Objective
Compare product performance against other typical wear
solutions already in use
Identify high wear region within plant to accelerate trial
IE. post change in direction i.e. Elbow or tee
Achieve a life cycle of 3 times a standard campaign of 62
weeks - (186weeks)
Trial Methodology Manufactured 10 spools – 400 NB, 1 spool 450 NB.
Set 12 thickness control locations per spool and measured
thickness with Ultrasonic methods
Nov 2010 - Installed 11 Spools to process stream within
an Alumina Refinery - Bauxite liquor / Slurry Transfer
at digester inlet and outlet
Monitored quarterly with Ultrasonics for first year
Monitored 6 monthly 2011-2014
Feb 2014 spools removed for planned shut and inspected
Spool repaired and re-installed Feb 2014
Trial Process conditionsTypical Parameter Values
Test Spool N.B. 400 NB Schedule 80
Operating temperature (degrees Celsius) 150-170
Nominal Flow velocity (meters per second) 4.2 – 4.9
Maximum Raw Caustic (grams per litre) 300
Nominal Raw Caustic (grams per litre) 280
Slurry Density (specific Gravity) S.G – 1.27
Solids Density (grams per litre) 120 - 180
Solids Makeup (Percent) 5% undissolved alumina
45% iron mud
45% silica sand
5% miscellaneous organics
Operating Pressure (kPa) 400 – 460
Cycle Continuous use
Results spool - ID H81258
Installed Nov 2010
Thickness at install Range 25.6mm to 27.0mm
Wear After 1 year No discernible wear
Wear Year 2 to 4 Fixed flange and Body section of spool 2.0mm (max) per
wall
Swivel flange end 5.0mm for first 30mm from connection
•All spools still in use after 260 weeks (4 campaigns) with only minor repairs
•Previous Weld overlays spools required repair or replacement at end of 62 week
campaign
•Many previous spools needed urgent repair to be carried out during the campaign
• This trial and further installation of spools numbering over 400 in service to date
have exceeded all expectation.
• The 11 spools in the original H81 trial are now operating for the 5th campaign and
are expected to be operational for at least 4 further campaigns, 9 times the life of
previous spools.
Advantages of UT inspection Combined product performance and the ability to measure
thickness leads too;
In service wall thickness testing, the process can continue
uninterrupted
In Situ testing during shut down avoids the need for
disassembly of spool to inspect - saving labour resource
Increased confidence in remaining wear material allows for
reduced inspection intervals
Boxing of tubing is potentially no longer required as wear
can be monitored and remaining life can be forecast