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M. V. Mehta et al.
1 Introduction
Engineering parts are as often as possible worked in extreme conditions. The surface
changes must be carried out to expand the high-temperature wear-and corrosionresistant properties, thus enhancing the self-life of engineering equipment [1]. In
industries like oil, pharmaceutical, and natural gas industries, the corrosive surface
of engineering parts is one of the major issues. It happens essentially in petroleum,
natural gas, and petroleum byproducts lines because of contamination by corrosive
environments and/or by abrasive materials [2]. The nickel–chromium–molybdenum
Hastelloy – C series alloys C-4, C-22, C-276, and C-2000 (one of the latest developed alloys from Hastelloy family) are highly corrosion-resistant nickel-based alloys
widely used in above-mentioned applications due to there outstanding corrosion- and
heat-resistant properties. This Hastelloy – C series alloys contain a nominal 54% Ni,
15% Cr, 17% Mo, and smaller addition of other alloys such as W, Fe, and Cu to get
desired properties [3, 4].
For types of components and equipment in chemical processing industries, a
unique corrosion-resistant weld overlay denotes a preventive measure against structural deterioration. Weld overlay with noble material such as Hastelloy or Inconel
on carbon steel, stainless steel, or low alloy steel is profitable to manufacture. It is
impervious to surface deterioration [2]. Protection to low-grade alloy with noble and
expensive material such as Hastelloy and Inconel is an effective and economical solution since the surface of equipment is only exposed to the corrosive side (commonly
processing side/flow side) [5]. Especially, for this sort of setup, the governing factors
are the economical value, operating environment, and the mechanical properties of
low-grade steel for the manufacturing of heavy engineering equipment merged with
the exceptional, superior characteristics of resistance to corrosion of the noble and
expensive alloys utilized for weld overlays [2]. The nickel–chromium–molybdenum
superalloys have been regularly used as surface weld overlay material to protect the
surface of the equipment, for example, in carbon steel, low alloy steel, or stainless
steel material to enhance the service life, reduce cost, or remove intervention for
unprepared in-service maintenance. Additionally, defect-free sound weld overlay
ensures no sudden collapse, failure, and accident during service [2].
For corrosion-resistant weld overlay, dilution is a major concern for manufacturers, and they must control dilution as much low as possible; both reduce the undesirable content at their surface and avoid the formation of undesirable microstructural phases that are prone to corrosion. To control the dilution of weld overlay,
various possible, recommended, and suggested techniques are used that reduce the
heat input, arc energy, and control depth of penetration. Such kind of welding techniques includes changing in the current alternative to direct current and vice versa,
inverting the polarity or changing the contact tube to work distance, besides the
used advanced processes like plasma transferred arc welding (PTAW), hot wire TIG
(HWT), multiple electrode processes, cold metal transfer (CMT), elecroslag strip
cladding (ESSC), and submerged arc strip cladding (SASC) [6].
M. V. Mehta et al.
1 Introduction
Engineering parts are as often as possible worked in extreme conditions. The surface
changes must be carried out to expand the high-temperature wear-and corrosionresistant properties, thus enhancing the self-life of engineering equipment [1]. In
industries like oil, pharmaceutical, and natural gas industries, the corrosive surface
of engineering parts is one of the major issues. It happens essentially in petroleum,
natural gas, and petroleum byproducts lines because of contamination by corrosive
environments and/or by abrasive materials [2]. The nickel–chromium–molybdenum
Hastelloy – C series alloys C-4, C-22, C-276, and C-2000 (one of the latest developed alloys from Hastelloy family) are highly corrosion-resistant nickel-based alloys
widely used in above-mentioned applications due to there outstanding corrosion- and
heat-resistant properties. This Hastelloy – C series alloys contain a nominal 54% Ni,
15% Cr, 17% Mo, and smaller addition of other alloys such as W, Fe, and Cu to get
desired properties [3, 4].
For types of components and equipment in chemical processing industries, a
unique corrosion-resistant weld overlay denotes a preventive measure against structural deterioration. Weld overlay with noble material such as Hastelloy or Inconel
on carbon steel, stainless steel, or low alloy steel is profitable to manufacture. It is
impervious to surface deterioration [2]. Protection to low-grade alloy with noble and
expensive material such as Hastelloy and Inconel is an effective and economical solution since the surface of equipment is only exposed to the corrosive side (commonly
processing side/flow side) [5]. Especially, for this sort of setup, the governing factors
are the economical value, operating environment, and the mechanical properties of
low-grade steel for the manufacturing of heavy engineering equipment merged with
the exceptional, superior characteristics of resistance to corrosion of the noble and
expensive alloys utilized for weld overlays [2]. The nickel–chromium–molybdenum
superalloys have been regularly used as surface weld overlay material to protect the
surface of the equipment, for example, in carbon steel, low alloy steel, or stainless
steel material to enhance the service life, reduce cost, or remove intervention for
unprepared in-service maintenance. Additionally, defect-free sound weld overlay
ensures no sudden collapse, failure, and accident during service [2].
For corrosion-resistant weld overlay, dilution is a major concern for manufacturers, and they must control dilution as much low as possible; both reduce the undesirable content at their surface and avoid the formation of undesirable microstructural phases that are prone to corrosion. To control the dilution of weld overlay,
various possible, recommended, and suggested techniques are used that reduce the
heat input, arc energy, and control depth of penetration. Such kind of welding techniques includes changing in the current alternative to direct current and vice versa,
inverting the polarity or changing the contact tube to work distance, besides the
used advanced processes like plasma transferred arc welding (PTAW), hot wire TIG
(HWT), multiple electrode processes, cold metal transfer (CMT), elecroslag strip
cladding (ESSC), and submerged arc strip cladding (SASC) [6].