T.O. 1-1A-9 TABLE 2-18.  FUSION WELDING CHARACTERISTICS OF CORROSION RESISTING STEEL - GENERAL(CONT’D) ALLOY/DESIGN RECOMMENDED FILLER MATERIAL/SPEC HEAT TREATMENT REMARKS TYPE STRUCTURE TYPE ELECTRODE ROD PREHEAT POSTHEAT MATERIAL TREAT 321 Austenitic 347 MIL-E-6844 Class 5, Same as Postweld One of best grades for Class 5, Class 5A, above. anneal not re- fabrication of parts by AMS 5681 AMS 5680 quired unless welding.  Not subject material is to intergranular cor- overheated to rosion unless over above 1900 F heated to above 1900 F. (See Remarks). Heating at this tem- perature followed by rapid cooling & re- heating at approxi- mately 800 - 1500°F will reduce resistance to intergranular at- tack due to carbide precipitation.  For restoration of this sensitized condition, material should be stabilized or fully annealed. 347 Austenitic 347 MILE-6844 MIL-R-5031 Same as Post well an- Primary use is for 348 Austenitic Class 5 Class 5 above. neal not re- fabrication of parts AMS 5681 Class 5A quired unless by welding without AMS 5680 overheated to postweld annealing, above 2150 F however, it is harder for prolonged to fusion weld than periods, how- 304L.  Difficulty may ever, after be experienced in fabrication a welding heavy sections stress relief due to cracking.  For is recommen- restoration of sen- ded. sitized condition, material should be stabilized or fully annealed. 403 Martensitic 309 MIL-E-6844 MII-R-5031 300 F 1350 F Fusion welding of 410 310 Class 2/3 Class 2/3 followed by type 403 and 410 can 416 410 AMS 5777 AMS 5776 cooling at rate be accomplished us- of 100 F per ing electrode of same See Remarks hour maximum composition if mater- to 1100 F is ial is to be heat treat- necessary to ed after welding. prevent crack- Type 309/310 ele- ing.  Type 416 ctrodes can be used should be an- if material is to be nealed at 1450°    used in a welded con- F after weld- dition.  416 is not ing to improve generally recommend- ductility & ed but can be fusion corrosion re- welded to a limited sistance. extent.  416 requires annealing after weld- ing to improve both ductility and corros- ion resistance. 2-96