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Weldability
Mr. MUBASSIR I. GHONIYA of Mechanical Engineering.
Enrolment No. 136010319024 has Satisfactorily
completed his term work in F.T for the ending in APRIL
2016.
Date :-
Guide H.O.D
Sign Sign
TOPIC
 WELD ABILITY
DEFINITION OF WELDABILITY
 Two metallic parts of same or different metals mixed
and fused when welded with or without applying
pressure, with or without use of filler metal then the
ease with wich the metal joint will properly of joining
metal or metals called weldability
 The easy with which welding of a give material can be
done without producing any defect is called weldability.
 Also be defined as the capability of a metal to be
welded under the fabrication conditions imposed
satisfactorily in the intended surface.
Weldability
MEANING OF WELDABILITY
 Weldability is considered as ease of accomplishing a
satisfactory weld joint and can be in determined from
quality of the weld joint, effort and cost required for
developing the weld joint.
 While efforts required for producing sound weld joint
are determined by properties of metal system in
consideration namely melting point, thermal expansion
coefficient, thermal and electrical conductivity, defects
inherent in base metal and surface condition.
 Therefore, weldability of a metal is considered as a
relative term.
 The metallic material with adequate weldabilityshoud
fulfill the requirements like,
A. The metallic material with adequate weldabilityshoud
fulfill the requirements like,
B. Contribute to good weld quality even with high
dulation.
C. Have unchanged corrosion resistance after welding.
D. Should not be embrittled when stress relieving.
CONCEPT OF WELDABILTY
The concepts of weldability are,
1. Metallurgical compatibility of a metalalloy to be
welded with any specific welding process. Metallurgical
compatibility means that the base metal and weld
metal can be combined with the degree of dilution
encountered in a specific process without the
production of deliteriousconstituens and phases.
2. Ability of the metalalloy to be welded with mechanical
soundness. The mechanical soundness must meets
soundness requirments and normal engeeniring
standards.
3. Service ability of the resulting welded joint. The
servicebility may concern the ability of the welded
structure or joint to work under low and high
tempratures impacts etc.
FACTORS AFFECTING ON
WELDABILITY
 Meting point of metal: Materials with medium
melting point can be welded very easily.
 Thermal conductivity: Material with high thermal
conductivity (K) is treated as difficult to weld materials.
 Reactivity: If the material reacts with air, water or
surroundings it become difficult to weld.
 Coefficient of thermal expansion of metals:
Material with high thermal expansion coefficient, it
becomes difficult to weld.
 Electrical resistance: Higher the electrical resistance
of the material, it becomes difficult because it requires
lot of heat energy.
 Surface condition: The material with dirty surface it
becomes difficult to weld.
 Strength and brittleness of metal at high pressure.
 Composition of metal.
 Heat treatment carrying out before and after welding.
 Thermal properties of the metals.
From the above mentioned factors whichever the
material is influenced by maximum number of factors, the
corresponding material is treated as very difficult to weld
and whichever the material is influenced by least number of
factors, the corresponding material is treated as very easy
weld material.
THE WELDABILITRY OF SOME METALS IN
DESCENDING ORDER IS AS UNDER.
1. IRON
2. STEEL
3. CAST IRON
4. LOW ALLOY STEEL
5. STAINLESS STEEL
IMPORTANCE OF WELDABILITY
1. As per the weldability of base metal and electrode
metal mechanically sound weld joint without crack and
produced. therefore to satisfy the needs of design.
2. weldability is an important quality. The fabrication
work is done using the metals having good weldability
can give strength of joint as per the design of the joint.
3. If weldability of the metals is good then special type of
welding process are not required to weld a metal.
4. The weld obtained by selecting metal having good
weldability does not produced brittle fracture.
5. Good weldability reduces the requirement of
preheating.
6. Weldability shows their capability to provide service as
per the design of the joint.
REFERENCES
 www.wikipedia.com
 www.slideshare.net

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Weldability

  • 2. Mr. MUBASSIR I. GHONIYA of Mechanical Engineering. Enrolment No. 136010319024 has Satisfactorily completed his term work in F.T for the ending in APRIL 2016. Date :- Guide H.O.D Sign Sign
  • 4. DEFINITION OF WELDABILITY Two metallic parts of same or different metals mixed and fused when welded with or without applying pressure, with or without use of filler metal then the ease with wich the metal joint will properly of joining metal or metals called weldability The easy with which welding of a give material can be done without producing any defect is called weldability. Also be defined as the capability of a metal to be welded under the fabrication conditions imposed satisfactorily in the intended surface.
  • 6. MEANING OF WELDABILITY Weldability is considered as ease of accomplishing a satisfactory weld joint and can be in determined from quality of the weld joint, effort and cost required for developing the weld joint. While efforts required for producing sound weld joint are determined by properties of metal system in consideration namely melting point, thermal expansion coefficient, thermal and electrical conductivity, defects inherent in base metal and surface condition. Therefore, weldability of a metal is considered as a relative term.
  • 7. The metallic material with adequate weldabilityshoud fulfill the requirements like, A. The metallic material with adequate weldabilityshoud fulfill the requirements like, B. Contribute to good weld quality even with high dulation. C. Have unchanged corrosion resistance after welding. D. Should not be embrittled when stress relieving.
  • 8. CONCEPT OF WELDABILTY The concepts of weldability are, 1. Metallurgical compatibility of a metalalloy to be welded with any specific welding process. Metallurgical compatibility means that the base metal and weld metal can be combined with the degree of dilution encountered in a specific process without the production of deliteriousconstituens and phases. 2. Ability of the metalalloy to be welded with mechanical soundness. The mechanical soundness must meets soundness requirments and normal engeeniring standards.
  • 9. 3. Service ability of the resulting welded joint. The servicebility may concern the ability of the welded structure or joint to work under low and high tempratures impacts etc.
  • 10. FACTORS AFFECTING ON WELDABILITY Meting point of metal: Materials with medium melting point can be welded very easily. Thermal conductivity: Material with high thermal conductivity (K) is treated as difficult to weld materials. Reactivity: If the material reacts with air, water or surroundings it become difficult to weld. Coefficient of thermal expansion of metals: Material with high thermal expansion coefficient, it becomes difficult to weld. Electrical resistance: Higher the electrical resistance of the material, it becomes difficult because it requires lot of heat energy.
  • 11. Surface condition: The material with dirty surface it becomes difficult to weld. Strength and brittleness of metal at high pressure. Composition of metal. Heat treatment carrying out before and after welding. Thermal properties of the metals. From the above mentioned factors whichever the material is influenced by maximum number of factors, the corresponding material is treated as very difficult to weld and whichever the material is influenced by least number of factors, the corresponding material is treated as very easy weld material.
  • 12. THE WELDABILITRY OF SOME METALS IN DESCENDING ORDER IS AS UNDER. 1. IRON 2. STEEL 3. CAST IRON 4. LOW ALLOY STEEL 5. STAINLESS STEEL
  • 13. IMPORTANCE OF WELDABILITY 1. As per the weldability of base metal and electrode metal mechanically sound weld joint without crack and produced. therefore to satisfy the needs of design. 2. weldability is an important quality. The fabrication work is done using the metals having good weldability can give strength of joint as per the design of the joint. 3. If weldability of the metals is good then special type of welding process are not required to weld a metal. 4. The weld obtained by selecting metal having good weldability does not produced brittle fracture. 5. Good weldability reduces the requirement of preheating.
  • 14. 6. Weldability shows their capability to provide service as per the design of the joint.