Butt welding of parts without melting

Welding process without melting is one of the methods of butt welding. It belongs to the category of pressure welding. The welding method is based on without melting The thermal effect of electric current, based on the Joule-Lenz law, and subsequent compression of the welded workpieces is incorporated. The cross-sectional area of parts welded in this manner reaches 200 mm.² and is used to join wire, small-section low-carbon steel pipes, and rods. This type of welding is well suited for low-alloy structural and low-carbon steels. Contact welding without melting It is successfully used for copper and aluminum alloys, which gives this method a wide range of applications.

Method of welding butt joints

Different Cmethod of welding butt joints Two methods allow for the technological process of strong and high-quality metal welding. One is the fusion method, and the other is non-fusion. Non-fusion welding, also known as resistance welding, involves heating the workpiece intensely and then pressing it down while simultaneously turning off the current. WITHmethod of welding butt joints The resistance method (without melting) includes sequential steps of preparing parts and joining them:

• To ensure successful welding, the surface to be joined must be thoroughly cleaned of dirt and oxidation. Any surface imperfections or roughness must be removed, as this will prevent uniform heating. Cleaning is especially important if the surface area is large. If the ends are not tightly sealed, oxidation of the metal on the joint surface will occur.
• The parts are then placed in electrode clamps and compressed. The compression force is significantly greater than in fusion welding. This ensures optimal surface heating;
• An electric current is passed through the metal, causing rapid heat generation at the ends of the parts. Plastic deformation occurs, and the electrical contact area increases. As a result, the overall resistance drops to zero. The metal is heated to a temperature of 0.8–0.9 T p.l. (T p.l. is the melting point of the metal). At this temperature, oxides are present on the surface of the solid metal. Oxide extrusion does not occur completely;
• The current upsetting begins, i.e. the metal is squeezed out of the joint;
• Next comes the current-free upsetting. The pressure may increase or remain equal to the heating pressure, depending on the type of metal. The upsetting should be optimal in size and localized in the joint area, allowing the overheated metal and oxides to be expelled. A burr forms around the joint.

Method of welding butt joints They differ in that pressure is the leading factor in the formation of metallic bonds in a welded joint. The melting process of the metal promotes recrystallization of the metal at the joint.

GOST contact butt welding

Standardization defines the conditions for carrying out welding works by the method of butt welding with resistance and fusion.OST contact butt welding specifies definitions and terms according to ISO 15607 and ISO 6520-2. Preliminary specifications for the butt welding process shall be developed in accordance with ISO 15609-5.OST contact butt welding has its own requirements for testing test welds. Certification of resistance welding setters complies with GOST EN 1418. The current standard contains requirements for the resistance welding process in accordance with ISO 4063. GOST contact butt welding R ISO 15614-13 and GOST R ISO 15614-14 have a number of normative references to international standards for butt welding.