Sell coppe-nickel series resistance wires @China (Mainland)

Nickel-Copper alloy welding wires

 

Uses:

1 nickel and nickel alloy welding commonly used nickel-based alloy is divided into four series:

(1) by kang nickel Inconel (Ni - Gr - Fe)

(2) the Monel Monel (Ni - Cu)

(3) for Chloe Incoloy (Fe - Ni - Gr)

(4) the haas Troy Hastlloy (Ni, Mo and Ni - Gr - Mo department)

2 weldability analysis

(1) nickel and nickel alloy welding hot crack is the most common defects, the main reason is that of nickel and iron in the binary eutectic material with low melting point metal eutectic and nonmetallic eutectic. Especially sulphur, phosphorus eutectic melting point content much lower than that of nickel and iron (Ni - S is 645 ℃, the Ni - P is 880 ℃), when weld crystallization of low-melting-point eutectic liquid membrane residues in grain boundary area, and nickel and nickel alloy linear expansion coefficient is big, easy to produce larger stress, when welding the weld crystallization in low melting point of eutectic liquid membrane under the effect of shrinkage stress are prone to cracking.

(2) nickel and nickel alloys, especially the pure nickel, alloy, is your solid and liquid temperature interval is small, low liquidity, under the condition of fast cooling crystallization, gas extremely easily to escape to the appearance of porosity in the weld. So nickel and nickel alloy welding string cable should be used in energy, lower layer temperature, speed up the welding seam between the cooling speed, thoroughly remove before welding wire, parent metal groove in the oil, dirt, strict control of sulfur and phosphorus content in parent metal welding materials, to prevent the formation of cracks and pores.

3 welding methods of nickel and nickel alloy welding generally USES the manual tungsten argon arc welding and manual welding rod arc welding, melting polar inert gas protection welding methods, such as automatic submerged arc welding welding method may be adopted.

4 wire

4.1 welding material selection principle

4.4.1 the same iron nickel alloy, nickel alloy welding appropriate chooses the same welding material and the parent metal alloy system, without corrosion resistance requirements, also can choose different parent metal alloy system and welding material, but should guarantee the connection with the performance of the design requirements.

4.1.2 heterogeneous iron nickel alloy, nickel alloy of nickel and chromium austenitic steel welding the weld joint of dissimilar materials, selection should consider the following factors:

(1) the strength of the weld (including high temperature enduring strength) corrosion resistance.

(2) the difference of linear expansion coefficient, high temperature for a long time after work, can produce a permanent change in volume.

(3) the sensitivity of the welding crack, air hole.

4.2 common nickel alloy, nickel alloy welding material

4.3 common heterogeneous nickel alloy welding material selection

4.4 welding material drying (1) of the electrode before use should be according to the electrode product manual, certificate of quality or the requirements of the welding process instructions for drying.

(2) after baking electrode should be stored at 100 ℃ in the constant temperature box, welder recipients insulation tube should be used, such as lead time more than 4 h, should be to bake, but not more than two repeat number of baking. (3) recommended electrode drying temperature.

4.5 the requirement of welding material

(1) nickel and nickel alloy welding electrode, welding wire used in the pipe welding, flux, shielding gas, the electrode should have the factory certificate and certificate of quality.

(2) if the certificate of the welding quality of characteristic data, or when in doubt about its quality, should be necessary the reinspection according to relevant technical standards.

(3) welding material storage, storage should be consistent with JB/T3223-96 welding material quality management procedures and the requirements of related standard.

(4) cerium tungsten electrode, tungsten argon arc welding appropriate USES and meets GB4191 the inert gas shielded arc welding and plasma welding, cutting with cerium tungsten electrodes.

(5) the purity of argon welding nickel and nickel alloy use should not less than 99.99%. (6) during welding with argon gas pipeline appropriate USES plastic hose, unfavorable use rubber hose or other hygroscopic material of hose.

5 of welding environment, nickel and nickel alloy welding construction environment should meet the following requirements:

(1) the environment temperature is not lower than 0 ℃.

(2) manual welding when the wind speed is not more than 8 m/s, argon arc welding when the wind speed is not more than 2 m/s.

(3) the relative humidity is not more than 90%.

(4) the rain and snow weather.

(5) when the environmental conditions do not conform to the requirements of the above, effective protective measures should be taken back to welding.

6 construction preparation

6.1 construction standards in the petrochemical cr-ni austenitic steel, iron, nickel alloy and nickel alloy pipe welding regulation SH/T3523 field equipment industrial pipe welding engineering construction and acceptance standard "GB50236" nickel and nickel alloy electrode "GB/T13814" nickel and nickel alloy welding wire "GB/T15620

6.2 welding procedure qualification and welder test execution standard of welding procedure qualification and welder test execution field equipment, industrial pipe welding engineering construction and acceptance standard "GB50236 or the petrochemical cr-ni austenitic steel, iron, nickel alloy and nickel alloy pipe welding regulation SH3523 rules. Welding procedure qualification and welder examination project can cover welding products.

6.3 according to the design documents, related standards and welding procedure qualification, and prepare welding process instructions.

7 welding process

7.1 weld cleaning

(1) clear weld groove, blunt edge and scope of 30 mm on both sides of weld bead.

(2) welds oxide film with clear file, grinding wheel.

(3) welds dirt, grease, paint application of acetone, alkali, special synthetic agent or clean up.

7.2 welding matters needing attention

7.2.1 when welding on the premise of guarantee good penetration and fusion, within the scope of the process parameters as far as possible use small welding line energy, short arc swing, swing, or small operation method. 7.2.2 when welding thicker need multi-layer welding shall meet the following requirements:

(1) in addition to the backing welding appropriate USES more than the rest of the welding layer welding.

(2) layer temperature should be less than 100 ℃.

(3) each layer after each welding slag, weld surface shall be completely eliminated and eliminate all kinds of surface defects.

(4) of each layer of the welded joint to stagger.

7.2.3 using solid core wire or not wire filling tungsten argon arc welding, the welding seam on the back should be filled argon, practice the inside protection, protection measures can be adopted in the whole or partial argon filling pipe two methods, and shall meet the following requirements:

(1) at the beginning of the tube filled with argon gas flow can be appropriately increased, air completely ruled out rear can confirm tube welding.

(2) when the welding argon flow can gradually reduce, in order to avoid argon filling the back pressure is higher and cause weld in forming occurs or root incomplete fusion phenomenon.

7.2.4 tungsten argon arc welding, the heat end of the wire should always be under argon protection. In order to strengthen protection effect in the welding nozzle one auxiliary conveying protection gas drag is back home.

7.2.5 forbidden arc scratches on the surface of the weld, and it is strictly prohibited in the weldment surface arc, arc.

7.2.6 ground wire welding power source, which is connected with weldment shall not directly contact with the workpiece, should adopt transitional connection and welding materials with the same material, in order to avoid pollution of iron.

7.2.7 welding should ensure the quality of arc and arc extinguishing arc extinguishing arc pit should be filled.

7.2.8 welded pipe diameter smaller, when great material of welding hot cracking tendency, should take on both sides of weld cooling copper pieces, or in cold water, ethanol, polishing the mop on both sides of weld, to reduce the weld temperature retention time, speed up the weld cooling.

7.2.9 welding must be timely completion of the surface of the welding slag and splash around, clean up the splash proof materials.

7.2.10 avoid pollution in welding construction, hammer should adopt stainless steel, stainless steel wire brush, special grinding wheel.

7.3 welding process parameters of different series of nickel and nickel alloy welding technology parameter is slightly different

 

Post by jinbiao zhao    Minerals & Metallurgy    @2014-09-28 20:35:59