No abstract

Cored wires are used in numerous welding processes with or without external gas or flux shielding. Submerged arc welding (SAW) with cored wires, seamed or seamless, for joining mild and low alloyed steel grades is a technique that has demonstrated clear advantages during the three last decades. Ever since its invention, the SAW process has evolved with one main goal: to combine quality with productivity. With low alloy wires, the benefits have already been clearly demonstrated and widely exploited. However, little has been written on SAW and cladding with cored wires for corrosion or heat resisting applications. Its extension to high alloy compositions brings corresponding benefits and adds some specific and unique features. This paper focuses on consumable specificities and on the quality and productivity features of SAW with CRA (corrosion resistant alloy) cored wires. It describes the potential as well as the limitations of this technique. Cored wires are now used for submerged arc welding of almost all stainless steels ranging from soft martensitic to super-duplex, and for a series of nickel base compositions as well as for cladding cobalt base alloys. Examples of industrial applications with austenitic, duplex, martensitic and heat resisting stainless steels are given to illustrate the potential of the cored wire solution. 13 Ref., 4 Tables , 25 Figures.

Comparative investigation of hot cracking sensitivity of commercial welding wires has been performed. It is shown that an all-purpose method of weldability evaluation can be the machine method with controllable forced deformation during TIG welding (PVR-test method), which allows separating the conditions of initiation of solidification cracks and ductility dip cracks in the weld and HAZ metal, and provides comprehensive information about quantitative characteristics of cracking sensitivity. 6 Ref., 9 Figures. K e y w o r d s : weldability, hot cracks, crack resistance evaluation, high-alloyed steels, nickel alloys

s.I. Kuchuk-Yatsenko (vice-chief ed.), V.N. Lipodaev (vice-chief ed.

Causes for fracture of repair layer deposited with electrodes of E-08Kh20N9G2B type on the surface of St3sp (killed) steel lining of water wheel chamber of HPS hydraulic unit are analyzed. It is established that its failures (cracking, delamination) arise as a result of lower chromium content (less than 12 %) and formation of martensite phase in the transition zone between steel St3sp and high-alloyed deposited metal. State of transition zone between St3sp and deposited metal of E-10Kh25N13G2, E-11Kh15N25M6AG2 and 10Kh28N14G2 type at welding current variation in the range of 80-140 A has been studied. It is shown that sufficient content of chromium (less than 12 %) and absence of martensite in the transition zone can be ensured in the case of application of electrodes of 10Kh28N14G2 type for repair surfacing at limitation of Iw to not more than 90 A. 6 Ref., 5 Figures, 1 Table.