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.
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