1. MANUFACTURERS OF A DIVERSE RANGE OF ADVANCED WELDING CONSUMABLES SECTION 9 NSB-307 A BALANCED LIME-RUTILE FLUX COATED SURFACING ELECTRODE DEPOSITING FULY AUSTINITIC WELD METAL WITH A NOMINAL 19Cr-9Ni-6Mn DATA SHEET NO. 139 SPECIFICATION AWS A5.4 CLASSIFICATION E307-16 PRODUCT DESCRIPTION The design of the electrode is synthetic, ie: a mild steel core wire with the alloying elements contained in the flux. The weld deposit is austenitic and metal recovery is some 135% with respect to weight of the core wire. A blend of silicates is used to bind the flux that ensures both coating strength and resistance to moisture absorption. WELDING FEATURES OF THE ELECTRODE The electrode is stable on both AC and DC. Initial arc strike is easy, as is restriking. The weld seams are smooth, bright and convex in shape. Slag is readily detachable. The weld metal is more resistant to solidification cracking than straight 14Mn types thus allowing higher pre-heats and interpass temperatures to be used on thick sections. APPLICATIONS AND MATERIALS TO BE WELDED The electrode may be used to weld Hadfield 13/14% manganese steel or similar, or surfacing mild steel components. As deposited the weld is soft and ductile but under impact loading, it rapidly work hardens and thus resistant to wear by friction and abrasion. Recommended for rail tracks, crossing parts, crusher rolls, bucket teeth and similar. WELD METAL ANALYSIS COMPOSITION % BY Wt. C Mn Si S P Cr Ni Mo Cu Fe MIN 0.04 3.3 - - - 18 9.0 0.5 - MAX 0.14 4.75 0.9 0.03 0.04 21.5 10.7 1.5 0.75 TYPICAL 0.1 4.2 0.5 0.02 0.02 20.1 10 0.7 0.1 Bal. WELD METAL HARDNESS (ALL WELD METAL) Hardness using pre-heat or interpass temperature up to 200°C on either mild steel (3 layers) or 14Mn steel (1 layers) HV as welded 220 work hardening will achieve HV450. The weld metal is not-heat-treatable, thus surfaced thick steel sections may be stress relieved. WELDING AMPERAGE AC or DC+ Ø (mm) 2.6 3.2 4.0 5.0 MIN 80 100 140 170 MAX 120 150 190 220 OTHER DATA Electrodes that have become damp should be re-dried at 150 o C for 1 hour. RELATED PRODUCTS Please contact our Technical Department for detail. WI-0304 DS139 NSB-307, Rev. 1, Date 01.08.2009