tailieunhanh - Mechanical Engineers Reference Book 12E Episode 16

Tham khảo tài liệu 'mechanical engineers reference book 12e episode 16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Welding soldering and brazing 16 55 Types of joint Ths types of joint used and their associated weld types are described in detail in BS The commonest joint types are butt T corner and lap. Butt joints These are joints between parts that are generally in line. If two plates are placed in contact a close square butt joint they can be welded with full penetration by one run of weld metal deposited by a manual welding process from each side provided that the plate thickness does not exceed approximately 8 mm Figure . However plate above 6 mm thickness is generally bevelled and the Vee edge preparation formed is filled by depositing a number of runs of weld metal. If high-cur rent mechanized welding processes are used penetration of the weld may be at least double the above dimensions and for electron beam welding may be many times as high. T joints and corner joints The parts may be joined by fillet welds or butt welds made by an arc welding process Figure . Lap joints These are commonly used for sheet metal up to about 3 mm thick in which one sheet is overlapped by another. This type of joint is used for soldering brazing resistance spot or seam welding and for arc spot welding plug welding as well as for adhesive bonding. For material of 3 mm or thicker even up to 10 mm lap joints are occasionally used and fillet welds are deposited at the plate edges by arc welding. Welding processes The various welding processes can be used to join the majority of metallic materials whether in cast or wrought form in thickness from 1 mm or less up to I m or more. A simple classification of welding processes is shown in Figure . For a complete classification and for definitions of the processes BS 499 Pt I10 should be referred to. A description of the welding processes is as follows. Manual metal arc welding Manual metal arc welding referred to in the USA as shielded metal arc welding is the most widely used process and accounts .