Shield Metal Arc Welding Process
Shield Metal Arc Welding Process (SMAW) For undergoing the Arc Welding process in a shield metal we need a base metal. After that we will go for a consumable electrode arrangement which is enclosed with some flux. We are also using a welding machine which consists of a positive as well as a negative terminal. This electrode will be connected to the welding machine. After this arrangement we will correct the regulator reading between 60 to 80 amps. At the starting stage of this process, we will maintain a small gap between the base metal and with the weld electrode. The electrons from the base metal will attract to the electrode and a heat will be generated at the end portion of the electrode. Weld metal will melt and it will mix up with the flux to produce the slag on the base metal.
Course Curriculum [Welding Inspection]
Welding terms and definition ypes of weld Types of weld joint Welding position Typical duties of a welding inspector Welding symbols Codes and standards Welding parameters welding consumables Manual Metal Arc Welding Process (SMAW) Tungsten Inert Gas Welding Process (GTAW) MIG/MAG Welding(GMAW) Sub Merged Arc Welding Process Defects and Imperfection Cutting process Heat treatments stages Material inspection Documentation Leak and pressure testing
Welding procedure specification & Welder
Welding procedure specification and welder qualification WPS (Welding Procedure Specification) is prepared by welding engineer .first welding engineer needs to prepare a PWPS (Preliminary Welding Procedure Specification), it is a technical note contains parameters related to welding.To meet the requirements of the design engineer the welding engineer has to prove in front of design engineer or the client company that the product have all the features which are expected by the firm. The welding engineer should prepare a technical document containing • Type of welding to be used. • Type of electrode to be used in welding • The current and electrode polarities • The size of electrode to be used • The base material specification The PWPS, PQR and SWPS are prepared by the welding engineer and its execution is done by welding inspector WPQ (Welder Procedure Qualification) The contractor has to propose a welder. The welding inspector have the authority to qualify the welder, he has to review the history records of the welder. Once the history records are satisfactory then he is permitted by the welding inspector to prepare the test coupon. Then coupon is subjected to visual examination. Once the visual examination is satisfactory then it is subjected for NDT or DT. If the NDT or DT is satisfied then welder issues a welding certificate with a validity of 6 months. If welder disqualifies a new welder will be proposed by the contractor or the welder has to prepare the test coupon.
Measures to be followed by welding inspector
Mandatory measures to be followed by welding inspector There are four steps to be followed by the welding inspector such as 1) He Should maintain a distance of 600 mm from the job 2) He should inspect the job at an angle of 30 degree or below 90 degree inclined position 3) If he is going to inspect the job inside a room then the room contains the illumination intensity of 300-500 lux 4) Should maintain a magnifying lens with range of x2-x5 to analyze the welding defects
Duties of a Welding Inspector
Welding Terms & Definitions
Welding is process of joining two metal pieces with the application of heat or pressure or simultaneously. whereas autogenous welding is nothing but no external fill up metal is added during welding . there are another types of welding such as sound quality welding that is if the fill up material is added between the two metal pieces then a perfect bonding will get in certain value .In case of homogeneous welding two material combing through the welding have similar chemical and mechanical properties in nature, where as heterogeneous welding the combining metals have similar chemical and mechanical properties in nature , but the welding deposit being in the process having a distinct mechanical and chemical properties. Apart from this welding dissimilar welding or DMW(dissimilar weld metal) joining is also there that two material combing for welding will have distinct chemical and mechanical properties. Complete features of welding plates are parent metal, weld metal, weld face, toe of the weld , HAZ(heat affection zone), excess weld metal and root of the welding and the types of joints are 1.butt joint 2.T joint 3.corner joint 4.edge joint 5.crusiform joint 6.lag joint