WELDING AND TYPES OF WELDING

WELDING
Parts are joined together by Fusion. Fusion is brought about by a combination of heat and pressure between parts being joined. In normal welding processes very high temperatures and little or no pressure is used.

Welding conditions

•   Smooth joint surfaces that match each other

•   Surfaces clean and free from oxides, grease and dirt.

•   Metals to be joined have same microstructure

•The metals should be good quality (no internal impurities)

Welding Preparation

•Before starting a weld, the joint edges should be carefully prepared. 

•   Beveling large edges

•   Cleaning (Chemical/Mechanical)

Weld Joints   -  Parts of a Weld Joint

•Joint root

•Groove face, Root face and Root edge

•Root opening and Bevel

•Bevel angle, Groove angle and Groove radius

Weld Joints   -  Types of Weld Joint

•Butt Joint

•Lap Joint

•T Joint

•Corner joint

•Edge Joint

•Splice Member

Joint Root

Joint root is that portion of a joint to be welded where the members are closest to each other

•The joint root may be either a point, line, or an area

•The joint roots are shown as shaded areas in (A)-(D) and lines in (E) (F)

Groove face, Root face and Root edge

•Groove face is “ that surface of a member included in the groove”

•Root face (land) is “that portion of  the groove face within the joint root”

• Root edge is a root face of zero width

Root opening and Bevel

•Root opening is the separation between the work pieces at the joint root

•Bevel (chamfer) is an angular edge preparation

Bevel angle, Groove angle and Groove Radius

Butt Joint

A joint between two members aligned approximately in the same plane.

Lap Joint

A joint between two overlapping members

T Joint

A joint between two members located approximately at right angles to each other.

Corner Joint

A joint between two members located at right angles to each other.

Edge Joint

A joint between the edges of two or more parallel or nearly parallel members

Splice member

is “ the work-piece that spans the joint  in a spliced joint

~ Single-spliced butt joint

~ Double-spliced butt joint with joint filler

Welding Techniques

There are many different methods of welding. The difference between them is outlined by two important features

•  The way the metal is heated

•  The way additional filler metal if any is fed into the weld

Types of Welding

•   Electric Arc Welding

•   Gas Welding

•   Resistance Welding

•   Friction Welding

•   Robotic Welding