as identified by operators and contractors to keep
transportation systems operational year round. Diligence
and commitment to maintenance ensure that necessary
reapplications of chromium carbide overlays occur regularly
to prevent an exponentially more costly line failure.
The worn cladding deposit may likely have fine
micro-cracking or relief cross checking common to these
chromium carbide hardfacing alloys. The relief cracking,
which typically occurs during and right after the overlay is
deposited, reduces stresses in the deposit and base metal
as cooling occurs, resulting in better overall adhesion of the
alloy and base metal and better overall field performance.
Once a section of pipe or an elbow is placed into
service, both the scouring action and pressure inside the
pipe will embed hydrocarbon contamination within the
relief cracks and the scoured metal surface. When pulled
from service for ID cladding repair and reapplication with
a standard chromium carbide, the chances are high, given
real-world experience, that these trapped hydrocarbon
contaminants will lead to unsatisfactory deposit beads
marked by multiple defects, including porosity that pose
a risk of cladding failure should the elbow be returned to
service (Figure 1).
While highly unlikely given the readily apparent
defective deposits, such a cladding repair would not
be returned to service given the tight governance most
contractors operate under. Removing the contaminated
layer and following up with additional cladding is both cost
and resource prohibitive, if the elbow can be salvaged and
reworked.
For this reason, the modified iron-based chromium
carbide pipe repair wire, Stoody® PR2009, was specially
formulated. Beginning with a chromium carbide metal cored
design, the alloy was optimised by the addition of special
deoxidisers to effectively eliminate weld deposit defects
commonly caused by hydrocarbon contamination. The
Mears’ Horizontal Directional Drilling is a single-source project
solution. Our clients benefit from our professional project
management, superior safety and quality, and over 40 years of
industry experience.
- Conventional HDD Crossings
- Marine crossings
(Water-to-Water and Shore Approaches)
- Hard Rock Drilling
- Design/build
- Engineering, Procurement and Construction
Mears EPC: Engineering solutions developed
to meet geographical, environmental and
climatic challenges head-on.
ENGINEERING, PROCUREMENT
&
CONSTRUCTION
MEARS GROUP, INC. - HORIZONTAL DIRECTIONAL DRILLING
2800 Post Oak Blvd., Ste. 3010
Houston, TX 77056
281-448-2488
Certified in Safety, Quality, and Environmental: OHSAS 18001:2007, ISO 9001:2008 and ISO 14001:2004
For more information, please visit our website at
Figure 3.
Stoody PR2009 showing 100X photomicrograph of a
weld deposit surface cross section.
