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