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Match the words in A with the definitions in B.
1.2 Before you start reading the text try to answer the following questions:
1. What parameters are welds classified by? 2. What types of welds do you know? 3. How can joints be subdivided within these types? 4. What does the choice of weld depend on?
Look through the text and grasp the general idea.
Weld joints.(3219п. зн.)
The weld joint is where two or more metal parts are joined by welding. Welds can be geometrically prepared in many different ways. The five basic types of weld joints are the butt, corner, tee, lap, and edge. Other variations exist as well—for example, double-V preparation joints are characterized by the two pieces of material, each tapering to a single centre point at one-half their height. Single-U and double-U preparation joints are also fairly common—instead of having straight edges like the single-V and double-V preparation joints, they are curved, forming the shape of a U. Lap joints are also commonly more than two pieces thick—depending on the process used and the thickness of the material, many pieces can be welded together in a lap joint geometry.
A butt joint is used to join two members aligned in the same plane. This joint is frequently used in plate, sheet metal, and pipe work. A joint of this type may be either square or grooved.
Corner and tee joints are used to join two members located at right angles to each other. In cross section, the corner joint forms an L-shape, and the tee joint has the shape of the letter T.
Various joint designs of both types have uses in many types of metal structures. A lap joint, as the name implies, is made by lapping one piece of metal over another. This is one of the strongest types of joints available; however, for maximum joint efficiency, you should overlap the metals a minimum of three times the thickness of the thinnest member you are joining. Lap joints are commonly used with torch brazing and spot welding applications. An edge joint is used to join the edges of two or more members lying in the same plane. In most cases, one of the members is flanged. While this type of joint has some applications in platework, it is more frequently used in sheet metal work. An edge joint should only be used for joining metals 1/4 inch or less in thickness that are not subjected to heavy loads.
Often, particular joint designs are used exclusively or almost exclusively by certain document.write("Welding Essentials: Questions & Answers (Expanded Edition)')\" onMouseOut=\"hideuarxtip()\">welding"); welding processes. For example, resistance spot welding, laser beam welding, and electron beam welding document.write("Artisan Welding Projects: 25 Decorative Projects for Hobby Welders')\" onMouseOut=\"hideuarxtip()\">welding"); are most frequently performed on lap joints. However, some welding document.write("Welding: Principles and Applications, Fifth Edition')\" onMouseOut=\"hideuarxtip()\">welding"); methods, like shielded metal arc welding, are extremely versatile and can weld virtually any type of joint. Additionally, some processes can be used to make multipass welds, in which one weld is allowed to cool, and then another weld is performed on top of it. This allows for the welding document.write("Basic Tig and Mig Welding: GTAW and GMAW')\" onMouseOut=\"hideuarxtip()\">welding"); of thick sections arranged in a single-V preparation joint, for example. The type of joint selected for any welding job may materially affect the quality and strength of the weld; the cost of labour and materials; the time and expense involved in preparing, jigging, and positioning the work; and other factors of like importance. The selection of the proper joint type depends on a number of factors, such as joint thickness and material, desired physical properties in the finished joint, size of the pieces being welded, accessibility of the joint, fit-up obtainable, available edge preparation equipment, number of pieces to be welded, and specifications of regulatory codes (if applicable).
1.4 Terminological vocabulary to the text “Weld joints.”Try to memorize the following words and word combinations.
1. a weld, n - сварной шов;
2. to be subjected to heavy loads – подвергаться большим нагрузкам;
3. to taper[6teipQ],v – сходить на конус, сужаться;
4. a preparation joint – подготовленное соединение под сварку;
5. to curve[kBv], v – изгибаться;
6. a right angle – прямой угол;
7. a cross section – поперечное сечение;
8. a multipass weld – многопроходный шов;
9. the finished joint – чистовой шов;
10. applicable [ 0AplikQbl] , adj – применимый, пригодный;
11. accessibility [ Qk4sesi0bilQti] , n – доступность, удобство осмотра и обслуживания;
12. to fit-up, v – сборка соединения под сварку;
13. positioning [pQ0ziS(Q)niN], n – установка в удобном для сварки положении;
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