9th August 2017 –
Opinion Page
Galvanised steel will bolster
rail safety. Cars and infra projects will suffer fewer corrosion and
maintenance issues.
SUNIL DUGGAL
Consumption
of zinc has grown in India over time, helping sectors such as infrastructure,
cosmetics, medicines, paints, rubber, surgical tools, plastics, textiles, soaps
and batteries expand and grow. But corrosion losses impact India’s GDP
considerably every year.
This
can be checked if we promote galvanisation (cover metals with zinc) in
construction. Western countries mandate the use of galvanising for steel
structures used in building bridges, highways, airports, metro stations,
railway stations, etc.
Zinc
is the fourth most widely consumed metal in the world — after iron, aluminium
and copper. Almost 50 per cent of the zinc mined across the world is used for
galvanising, 17 per cent for zinc alloying, 17 per cent for brass and bronze
making, 6 per cent in zinc semi-manufactures, 6 per cent in chemicals, and 4
per cent for other miscellaneous purposes.
India’s
consumption of zinc is rising day by day as new sectors are being explored to
take advantage of zinc. But its potential remains unrealised..
Coastal
infrastructure
Use
of Galvanised rebars in construction near coastal areas: Corrosion is one of the
major reasons for deterioration of concrete structures built near coastal
areas. Coastal salts coupled with humidity can corrode exposed metal surfaces
and penetrate any opening in the building.
Coastal
infrastructure within a range of 5 km is more prone to corrosions and becomes
progressively worse closer to the marine source.
According
to a study by the American Institute of Architects, it is essential to use hot
dip galvanised steel to make such coastal infrastructure-decay resistant.
Galvanised steel provides the much needed strength to rebars.
Auto
sector
Use
of galvanised car bodies: Globally there has been a discrepancy in using galvanised car bodies.
Indian car manufacturers use about 3 per cent galvanised steel for cars
manufactured and sold in the domestic market. However, they over 70 per cent
galvanised steel in exports to markets in Europe, Asia and Africa.
Indian
consumers don’t demand galvanised steel due to lack of awareness on the long
term benefits of galvanised vehicles.
Car makers in Europe, North America, Korea and
Japan have been using galvanised steel for car body panels for decades and
provide anti-corrosion and perforation warranties for a minimum of 10 years.
In India, the customers are advised to pay for
extra coatings to protect the body of the car after purchase. More than 60 per
cent of the cars in India have surface rust which reduces steel strength and
the life of the car, leading to safety hazard.
Steel has been used to make automobiles since the
early 1900s but corrosion resistance features became standard in vehicles
beginning in the early 1980s when Japanese cars gained entrance to the US
market.
Globally, the annual consumption of zinc for
auto-bodies today is roughly 120,000 tonnes. There is almost no galvanised
steel on Chinese-made vehicles except for exports from China by Volkswagen,
General Motors and others which also means that 20 million cars in China are
not using galvanised steel.
Globally, galvanised steel car bodies have been
shown to experience minimal corrosion attack which protects the structural
integrity and safety of the vehicle, improves the resale value, provides
consumer protection due to anticipated warranty improvements by the car
companies, lowers maintenance costs of under-body and structural components due
to the use of zinc coated steel, and saves consumers the costs of after-market
anti-corrosion treatments and annual inspections.
The railways
Corrosion of rails and fish plates: Galvanising of railway
tracks would not only be a significant initiative towards safety of trains but
would also give more life to the railway tracks. India’s rail tracks, spanning
over 125,000 km, happen to be the world’s third largest. The annual loss due to
pre-replacement of corroded rails is about Rs 440 crore. Many accidents have
been attributed to fishplates. Not just the fish-plates, even the bolts need
protection, protection from corrosion.
Experts have estimated losses of almost 4 per cent
of GDP per year on account of corrosion which may be avoided if the railway
tracks are galvanised. One of the significant aspects of railway track
maintenance is the detection of corrosion and the replacement of corroded
rails.
Corrosion reduces the life of rails to nearly half
its expected life. The rails have a life of 800 gross million tonnes which
works to approximately 12-13 years under normal traffic conditions in India.
The shorter life of rails resulting from absence of galvanising increases track
maintenance workload. Corrosion increases the pace of rails replacement and
interferes with normal railway movement causing inconvenience to passengers and
freight movers and revenue losses to the Railways.
According to a site inspection carried out by the
Commissioner of Railway Safety (eastern circle) PK Acharya, rusted rails could
have caused derailment near Kanpur that left 146 people dead and over 200
injured. The International Zinc Association advocates that Indian Railways
require corrosion- free tracks in case India is considering Bullet Trains.
Energy sector
Zinc powers the electricity distribution network: Since the advent of high
voltage lines, hot-dip galvanised steel has been used in the electric utility
market. Whether in a generation facility, substation, lattice tower, or
renewable energy components, galvanised steel has been a backbone of any global
economy.
According to a study by the American Iron and Steel
Institute, close to 1 million steel distribution poles have been installed in
the United States since 1998 and are being used by more than 600 US electric
utilities. India might be having more poles but how many are galvanised is
still to be assessed.
When India is looking ahead providing electricity
in every village and progressively moving towards Smart Cities project, Digital
India and Make in India, the very basis of infrastructure, the power
transmission, needs to be protected for many years.
If these four sectors mandate to address the issue
of corrosion and related safety, it would lead to not just efficiency and
savings worth millions of dollars for the Indian economy, but also build
long-lasting infrastructure.
The
writer is CEO of Hindustan Zinc.
