According to state regulations, and the following specifications:
"Materials and Welding 2006 published February 8, 2006
"Materials and Welding is the basis of the China Classification Society system of norms of a material and welding specifications. Reference for most of China Classification Society or construction specifications. The revised edition "material and welding specifications" (2006) (hereinafter referred to in this specification) on the basis of the 98 version of the merged Amendment in 2001, 2003 and 2004 years three, and then modify from.
In order to show that the modified situation, so that in the future to understand the norms of the commencement date. In the specification of the revised terms of standard specification provisions of substantive changes since 2001 to date modified, modify the nature of errata is not for the label.
This specification included by the end of 2004 and part of 2005 by the International Association of Classification Societies (IACS) of the uniform requirements of materials and welding.
To achieve the agency's product inspection system included in the specifications, the general part of the edition "standard" original "material and welding specifications" are replaced by new section 0 into the class rules. Clear the process of product testing requirements in this chapter.
Increase of the yield strength and corrosion test requirements of composite steel plate in a metal material; the same time, further expansion of the chemical composition of the steel forgings and mechanical properties of grade range, especially on the composition of the rudder forgings clearly defined.
The first time to adapt to the increasingly common phenomenon of the application of plastic materials in the shipbuilding industry in the specification two non-metallic materials, plastic materials, general requirements (Chapter 2, new), but also provides for specific application of the test methods are recommended. Also based on the level of China's industrial development, the original fiber reinforced plastic finishing, additions and deletions made a greater degree of molding workshop improved to some extent and the molding process adding new contents of the sandwich plate .
Three welding on the basis of the relevant provisions of last year, to adjust the structural material of austenitic stainless steel and duplex stainless steel, analysis, reference to the various classification societies norms, China's national standards, and physical performance, adjust the corresponding supporting welding materials, a new one. The IACS5 by W26 "aluminum Welding Alloysmaterial requirements" uniform requirements, added new Aluminium Welding Electrodematerials, adjusting the corresponding sets of specification aluminum alloy welding material content.
Various welding methods will have some harmful factors, different welding processes, the harmful factors are also different, in general there arc radiation, smoke, toxic gases, high temperature, high-frequency electromagnetic fields, radiation and noise of seven categories. Physical factors can be divided into an arc, noise, high frequency electromagnetic field, thermal radiation, radioactive; chemical factors a smoke and toxic gases.

Selection and use of nickel and nickel alloy welding rod

(1) The selection principles of nickel and nickel alloy electrode of nickel and nickel Welding Alloysis selected according to the welded base metal alloy grades, chemical composition and the use of environmental conditions. The electrode of the main chemical composition of deposited metal to be close to the main component of the base metal to ensure that the properties of welded joints and base metal. But taking into account the electrode alloy loss in the arc in the electrode should also contain some other elements to improve weld performance or welding performance.
Electrode using the same ingredients to reach the design requirements or there is no suitable similar alloy composition of the electrode, it is recommended that selection of the electrode of the high performance level, to ensure that the use of properties of the weld is not less than the base metal.
(2) the use of nickel and nickel alloy electrode Notes
â‘  base metal preparation: oil, paint, dust, dirt, carefully clear the surface of the base metal before welding.
â‘¡ In order to prevent the pores, the use of short-arc welding.
â‘¢ the use of smaller welding current, welding without preheating, maintaining low interpass temperature (<150 ° C), in order to avoid the overheating of the base metal.
â‘£ Tungsten Welding Electrodessmaller swings on both sides of the weld bead to stay a little longer, to facilitate stomatal and weld slag surfaced.
The ⑤ Crater attention to fill the crater, in order to avoid cracks in the crater.
â‘¥ nickel and nickel alloy microstructure of austenite, strong tendency of hot cracking in welding of fillet weld, the weld was convex shape, so you can better prevent heat cracks.