Mr. Mubassir I. Ghoniya has satisfactorily completed his term work in mechanical engineering at the university. The document then discusses the definition of weldability as the ease with which two metals can be joined together through welding. It outlines several factors that affect the weldability of metals, such as melting point, thermal conductivity, and surface condition. Metals with better weldability like iron and steel are easier to weld and provide mechanically sound joints.
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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.