Effects Of Welding Flux Additions On 4340 Steel Weld Metal Composition
Effects of Welding Flux Additions on 4340 Steel Weld Metal Composition An investigation was undertaken to better understand the transfer mechanism of flux systems and to quantify their oxygen potential BY P. A. BURCK, J. E. I N D A C O C H E A A N D D. L. O L S O N ABSTRACT. The effects of CaF2, CaO and FeO additions on weld metal chemistry were evaluated for the manganese — silicate flux system. Comparisons were made between AISI 4340 steel and lowcarbon steel welds to understand the weld metal chemistry. The results show that the elemental transfer from the slag to the weld metal and vice versa cannot be consistently explained using thermodynamic data; e.g., the carbon/oxygen partition is apparently controlled by a CO reaction in the 1010 steel welds, but the AISI 1020 and 4340 steel welds show constant carbon contents despite increasing oxygen levels. In addition, data are reported as a resource for future analytical and comparative purposes. Introduction Submerged arc welding of high integrity can be achieved through proper selection of the wire and flux combination for the specific base metal and welding parameters. Small amounts of alloying elements such as nickel, chromium and molybdenum are added to steels to increase strength, hardness or toughness, as is the case with AISI 4340 steel. Generally, welding low-alloy steels requires more careful control of procedures and selection of consumables than welding the carbon steels. Moreover, the oxygen potential of the flux influences the loss or gain of alloying elements during welding, the weld-deposit oxygen content, and the type, size and distribution of oxide inclusions in the solidified weld metal. The effective application of the submerged arc welding process for joining high-strength, low-alloy steels depends heavily upon understanding the behavior of the flux. Understanding the elemental P. A. BURCK and D. L. OLSON are with the Center for Welding and joining Research, Colorado School of Mines, Golden, Colo. J INDACOCHEA is with the University of Illinois at Chicago, Chicago, III. transfer mechanisms between the flux and the weld metal can be attained by studying the influence of each chemical additive on the flux behavior. To determine the many slag/weld metal chemical reactions occurring simultaneously during welding, a state of thermodynamic equilibrium has been assumed to be attained. The basis for this assumption is that the high temperatures and high surface-to-volume ratio associated with the welding process counteract the short time available for a reaction to be completed (Ref. 1). Chai and Eagar (Ref. 2) reported that the very short times and the large thermal gradients involved in the process prevent overall slag-metal equilibrium from being reached. They also reported that an understanding of kinetics, in combination with the thermodynamic limits of the process, would be necessary to determine the final weld metal composition. Blander and Olson (Ref. 3) also discussed the influence of kinetics, the role of interfacial reaction, and the degree to which equilibrium is approached. This paper is a part of the systematic investigation undertaken by the Colorado School of Mines (Refs. 3-7) to better understand the behavior of different flux additions to the manganese-silicate and lime-silicate flux systems. The influence of FeO, CaO and CaF2 additions to a manganese-silicate flux on AISI 4340 steel weld metal chemistry is reported here. In addi- KEY W O R D S Welding Flux Effects Flux Additions 4340 Steel Weld Metal Weld Composition Submerged Arc Fluxes 1020 Steel Weld Metal Ca 2 /CaO/FeO Addition Mn-Silicate Fluxes SAW Flux Systems tion, a comparison of the effects of CaF2 and FeO additions to a manganese-silicate flux on welds on AIS11020 and 4340 steels was made in an effort to understand the effect of alloying elements on weld metal chemistry. The results presented in this paper should be a useful database for future analytical modeling and comparisons. Materials and Procedure Single pass, bead-on-plate welds were made using the submerged arc welding process on AIS11010,1020 and 4340 steel base plates. The dimensions of the plates were 73 X 203 X 13 mm (2.9 X 8 X 0.5 in.). The welding wires used were AWS Type E70S-3 for welds produced on AISI 1010 and 1020 steels, and Type EM12K for AISI 4340 steel welds. Compositions of the base plates and welding wires are given in Table 1. The submerged arc welding process was performed using direct current, electrode positive. The welding parameters were maintained constant at 30 V, a travel speed of 8 mm/s (19 in./min), and the wire speed was varied to give 500 A. All welds were made with a heat input of 1.9 kj/mm (48 kj/in.). Three different flux systems were used in this investigation: Si02"MnO-FeO, Si02" MnO-CaO and Si0 2 -MnO-CaF 2 . The fluxes were prepared using reagent grade chemical powders. The flux compositions were reported as wt-% M n O because M n 0 2 decomposes to form M n O during the melting operation used to produce the fused flux. The iron ion in the fused flux was determined to be in the Fe state and is reported as wt-% FeO (Ref. 10). The reagent-grade powders were weighed and mixed prior to induction melting. The powders were then placed in a graphite crucible for the melting operation. All fluxes were brought to 1773 K. The crucible was then removed from the furnace and the flux poured onto a stainless steel plate to solidify. After cooling, the fused fluxes were crushed and sized. Fluxes sized 14 to 100 mesh were used for WELDING RESEARCH SUPPLEMENT 1115-s
The Effect of Flux Additions on AISI 4340 Steel Weld Metal Table 1 - -Composition of Base Metals and Weld ing Wires (wt-%) AISI 1020 Base Metal AISI 1010 Base Metal Elements 0.10 0.9 0.3 C Mn Si Mo Cr Ni S P N O Fe 0.23 0.54 0.3 — - 0.41 0.65 0.20 0.21 0.76 1.65 0.04 0.01 0.016 0.027 Balance — - 0.019 0.027 0.012 0.024 Balance 0.04 max 0.035 max — Balance this experiment. The fluxes were then baked at 973 K in air atmosphere for t w o hours to remove any residual graphite picked up from the crucible and to ensure moisture removal. Chemical analysis of the welds was made using Leco interstitial analyzers to determine weld metal carbon, oxygen and nitrogen contents. An emission spectrometer was used to determine weld metal manganese, silicon, chromium, nickel and molybdenum contents. The effect of each flux system on weld metal composition was determined by first obtaining the composition of the weld I A i i i i Si02 - M n O - CaO Si02- 40 w/o 0.6 0.31 0.55 0.65 0.50 1.25 — - — 0.018 0.011 0.003 0.024 Balance 0.01 0.01 — 0.008 Balance i 03 i I A FLUX AISI 4340 Si02 - M n O - FeO 3 0.08 1.16 0.43 - S'i02 - MnO - CaF2 FLUX o- The effect of CaF2, CaO and FeO additions to a manganese-silicate flux on AISI 4340 steel weld metal composition will be discussed first. Weld metal element content (wt-%) was plotted as a function of additions to the flux (wt-%) at the expense of MnO. The silica content of the flux was held constant at 40 wt-%. The weld metal carbon content is seen in Fig. 1 to have an average value of about 0.32 wt-% for the different flux additions that were used. Weld metal carbon content appeared to be independent of a particular flux composition. Weld metal silicon content as a function of flux composition is reported in Fig. 2. The CaO flux addition showed in general a loss of silicon from the weld metal to the slag as indicated by the negative delta quantities in Fig. 3. Silicon was seen to be transferred from the flux to the weld metal with additions of CaF2. The silicon transfer with FeO additions was found to have intermediate behavior, between that of CaO and CaF2 additions. The FeO flux additions produced the highest weld metal oxygen content, as seen in Fig. 4, while the CaF2 additions produced the lowest weld metal oxygen content. The oxygen content in the weld metal increased with increasing FeO flux additions; this is expected since FeO is more unstable than MnO. The CaO addi- EM12K Filler Wire metal analytically. The nominal composition of each weld was then calculated considering only the dilution effects of the filler wire and base metal composition. The difference between the analytical and nominal compositions, the delta quantity, indicates the contribution the flux makes to the weld metal composition. A positive delta quantity indicates element transfer from the flux to the weld metal. A negative delta quantity indicates element transfer from the weld metal to the slag. A zero value for a delta quantity indicates that the ion of interest in the flux has no thermodynamic desire and/or kinetic ability to react with the weld metal, since the slag and flux have the same specific ion composition. Results and Discussion 0.8 E70S-3 Filler Wire AISI 4340 Base Metal - FLUX I I I I I I - S i 0 2 - M n O - C a F 2 FLUX FLUX AISI 4340 Si02-MnO-CaO o- - S ' i 0 2 - M n 0 - F e 0 FLUX SKD2 40 w/o (constant) - (constant) — - - 0.6 - " z o Q z O CO tr A 0.4 -- a A ul kr 0.4 - hLU 2 8 2 o8 i a o r\ g r A Fl - HI 3 A i n J A I I i -"" o i 0.2 - 0.2 A - - 0.0 0.0 i i 20 30 FLUX ADDlT10N(wL%) i i 10 i i i i i i 20 30 FLUX ADDmON(wt%) J I 40 l 60 i 10 I I 40 L 20 40 30 MnO IN THE FLUX (wt.%) 60 20 50 40 30 MnO IN THE FLUX (wL%) Fig. 2 — Weld metal silicon as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. Weld metal carbon as a function of flux additions to a manganese fig 1 silicate flux used in submerged arc welding of AISI 4340 steel. -L I 116-sl MARCH 1990 I I I l 50
0.6 i i A i i - Si02-MnO-CaF2 o.oa r" A -Si02-MnO-CaF2 FLUX AISI O - S i 0 2 - M n O - CaO FLUX - S i 0 2 - M n O - FeO FLUX O - S i 0 2 - M n O - C a O FLUX 4340 FLUX -Si02-MnO-FeO AISI 4 3 4 0 Z u 5 a O FLUX Si02 40 w/o (constant) Si02 40 w/o (constant) 0.4 !J i UJ 0.06 It z z o o 'JJ X CD o oc 0.2 - tn 0.04 Ul - LU co ui 5 DC L1J LU 3 3 z ui LU Q I 0.02 0.0 O j ui UI -Q.2 60 50 0.0 20 30 FLUX ADDITION (wt.%) J I I I 40 30 MnO IN THE FLUX (wt.%) 60 20 Fig. 3 — Delta weld metal silicon as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. tions, at the expense of M n O , increased slightly the o x y g e n level of the w e l d metal, but t h e n it r e m a i n e d constant f o r additions greater than 10 w t - % . Such results w o u l d be e x p e c t e d since C a O is a v e r y stable oxide w i t h strong b o n d i n g t o o x y g e n . T h e r e w a s a slight decrease in w e l d metal o x y g e n c o n t e n t w i t h increasing CaF2 flux additions after an initial major decrease. For all the fluxes investigated, o x y g e n was o b s e r v e d t o b e transferred f r o m t h e flux t o the w e l d metal as seen b y the positive delta quantities in Fig. 5. T h e effect o f t h r e e different flux additions, CaF 2 , C a O and FeO o n t h e AISI 4340 steel w e l d metal manganese c o n t e n t s , is seen in Fig. 6. It is interesting t o n o t e that the manganese c o n t e n t d e c r e a s e d w i t h CaF 2 a n d FeO additions but remained constant w i t h C a O additions. T h e r e is s o m e e x p e c t a t i o n o f this b e h a v i o r f r o m steel-making t h e r m o d y n a m i c data. Even t h o u g h the manganese o x i d e c o n t e n t o f the C a O - M n O - S i 0 2 flux d e c r e a s e d , the activity of the manganese o x i d e in the slag remained relatively constant w i t h C a O additions, as seen in Fig. 7 (Ref. 8), and c o n s e q u e n t l y , t h e manganese activity in the w e l d metal w o u l d be constant, t o o . T h e o x y g e n available for the o x i d a t i o n of manganese in the w e l d metal also rem a i n e d constant, as s h o w n in Fig. 4 . The activity of M n O w a s f o u n d t o decrease w i t h increasing FeO additions, as suggested in Fig. 8 (Ref. 9). These equilibrium data are consistent w i t h the o b s e r v e d de- a o a: 0.08 50 i I I I O -S102 -MnO - CaF2 FLUX - S i 0 2 --MnO- - CaO FLUX -Si02 -MnO -FeO I I AIS 4340 FLUX Si02 40 w/o (constant) s 0.06 z - — - ui O x Ul (A Ul tt 20 Fig. 4 — Weld metal oxygen as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. i A 20 30 FLUX ADDITION (wt.%) l I I I— 40 30 MnO IN THE FLUX (wt.%) FeO u a - o - Fig. 5 —Delta weld metal oxygen as a function of flux additions to manganese silicate flux used in submerged arc welding of AISI 4340 steel. O 0.04 LU 2 F* o O LU o 0.02 -- X ott ui (/ ut ec i2 Ul o T / Ul Q Ul / 3 Q. o o \ - X u ec u (/ Ul LU Q CaO A \ I 0.0 60 y A CaF2 A I I i i 10 20 30 FLUX ADDITION (wt.%) I I I 1 40 30 50 M n O IN THE FLUX (wt.%) ec A i O. o I I 40 20 ui S ec 2 tn WELDING RESEARCH SUPPLEMENT 1117-s
1.2 l l l l l I I A - S i 0 2 - M n O - C a F 2 FLUX - 3 1.0 O - S i 0 2 - M n O - C a O FLUX - S i 0 2 - M n O - F e O FLUX Si02 40 w/o (constant) CaO „ A . A z -\ CD 0 \ LU OJ LU 0 z AISI 4 3 4 0 0.6 -o\ A CJ A o CJ A 0.8 -- tUl R tt - FeO - EK LU A \ A \ -M\ I I - S i 0 2 - M n O - F e O FLUX fc- yy o a z \. CaF2 A\ - 0.2 ck - o 0 A — O LU Z 2 I 0.4 tu co 3 0.6 -- I CaO , CaF2 S I - S i 0 2 - M n O - C a F 2 FLUX -SiO2-MnO-Ca0 FLUX AISI 4 3 4 0 Sr02 40 w/o (constant) - I I - FeO LU 2 - Ek A \ A . v LU - 3 Q CO I 0.4 I l 50 60 l I 20 30 FLUX ADDITION (wt.%) I I I I 40 30 MnO IN THE FLUX (wt.%) I 10 I -n - T]- J3 i 40 - - 20 I I -0.2 I 10 Fig. 6 - Weld metal manganese as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. l 50 A60 I I 20 30 FLUX ADDITION (wt.%) I I I I 40 30 MnO IN THE FLUX (wt.%) I I 40 20 Fig. 9 — Delta weld metal manganese as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. 0.4 1 A — l 1 l l O - S i 0 2 - MnO-CaF2 FLUX S i 0 2 - MnO-CaO FLUX - S i 0 2 - MnO-FeO l l AISI 4340 FLUX Si02 40 w / o (constant) 2 lime and lime — 2 O tr silicate saturation 0.4 ofMnO(S) CaF2 0.6 *MnO Fig. 7-Activity - - x o MnO saturation CaO 0.2 -- melts at 1500 C (Ref. 8). \ \ A o.o in CaO-MnO-Si02 \ A g A LU L 2 J- \ * - - a FeO A - % O -0.2 - a - S o LU \ 1 -0.4 1 10 l 60 'FeO a Fig. 8-Activities FeO a MnO in the FeO-MnO-Si02 118-sl MARCH 1990 system at 1500'C (Ref. 9). 50 o Ca I I I I 20 30 FLUX ADDITION (wt.%) I I I I— 40 30 MnO IN THE FLUX (wt.%) - I 40 20 Fig. 10 — Delta weld metal chromium as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel.
0.6 1 1 1 1 1 A - S i 0 2 - M n O - C a F 2 FLUX O - S i 0 2 - M n O - C a O FLUX 1 l AISI 4340 0.1 1 - - S i 0 2 - M n O - F e O FLUX Si02 40 w/o (constant) 2 1 a ca FLUX O -Si02-MnO-CaO FLUX -Si02-MnO-CaO FLUX AISI 4340 s a, O (constant) g - 0.0 1 -Si02-MnO-CaF2 Si02 40 w/o 0.4 3 Z LU 1 A A"- -A" ui % Q i O 2 z o z -0.1 LU 2 2 - LU 3 FeO CaF2 0.0 L 60 n i 10 A- i J Ui - a 1 n J 50 I I metal manganese as J L FLUX I J 50 40 CO ADDITION (wt.%) I ' ' 40 30 J 20 Y- MnO IN T H E Fig. 12 — Delta ganese silicate FLUX 0.8 Fig. 13 —Comparison of weld metal carbon as a function of CaF2 additions to manganese silicate in submerged arc welding of AISI 1010 and 4340 steels. FeO a n d C a O a d d i t i o n s t o a m a n g a n e s e silicate flux o n the activity of w e l d m e t a l m a n g a nese. was transferred f r o m the C a O f l u x a d d i t i o n s , as s e e n b y t h e p o s i t i v e d e l t a v a l u e s f o r b o t h f l u x s y s t e m s i n Fig. 9 . delta manganese changed from a positive to a negative value w i t h increasing F e O additions. These results transferred to the w e l d metal f r o m flux, b u t at a p p r o x i m a t e l y 20% the z O o o b e h a v i o r r e v e r s e s a n d m a n g a n e s e is t r a n s - o cc Ui cn ui tt. a. Ul a -- 0.4 ui 2 x o oc tu 3 UJ (/) Ul f e r r e d f r o m w e l d p o o l t o t h e slag. T h e effect of flux c o m p o s i t i o n o n O i Ul tr manga- n e s e o x i d e in t h e S i 0 2 - M n O - F e O flux, t h e Q. o ? suggest t h a t w i t h l o w F e O a d d i t i o n s , m a n g a n e s e is S l ui appear to be able to provide a qualitative Manganese (wt.%) weld metal nickel as a function of flux additions to a man flux used in submerged arc welding of AISI 4340 steel. Steel-making t h e r m o d y n a m i c activity data f l u x t o t h e w e l d m e t a l f o r t h e CaF2 a n d ui ec a f u n c t i o n o f F e O a d d i t i o n s as s e e n i n Fig. 6 . explanation for the behavior of the ui L 30 20 10 L 60 (wt.%) Fig. 11— Delta weld metal molybdenum as a function of flux additions to a manganese silicate flux used in submerged arc welding of AISI 4340 steel. L -0.5 J 20 30 IN T H E FLUX x a ec 40 L 40 Ul a o 1 i i i 20 30 ADDlTION(wt.%) FLUX I MnO weld a. o -0.3 CaO i -0.2 I-I LU m O n The ec - in o 3 crease Ui A LU - LU Q ui / o HI O sr A the t y p i c a l a l l o y i n g e l e m e n t s o f t h e AISI 4 3 4 0 Ui s t e e l p l a t e , i.e., S a. O c h r o m i u m , nickel a n d m o - l y b d e n u m , h a s b e e n d e t e r m i n e d . It was f o u n d that C a O additions t o t h e m a n g a nese-silicate overall flux losses chromium, in produce terms molybdenum the of greatest weld and metal nickel, o.o s h o w n in Figs. 1 0 , 1 1 a n d 1 2 , r e s p e c t i v e l y . T h e F e O additions t o the flux only cause t h e losses o f w e l d m e t a l c h r o m i u m and nickel w i t h n o effect o n w e l d metal mo- 10 20 C a F 2 IN as 60 J 50 I 30 THE FLUX l 40 (wt.%) l M n O IN T H E FLUX I 30 I I 20 (wt.%) Ul l y b d e n u m . But n o s i g n i f i c a n t m e t a l losses ec are f o u n d for these elements w i t h the additions o f CaF2 t o t h e flux. WELDING RESEARCH SUPPLEMENT 1119-s
0.16 I I I I S i 0 2 - M n O - C a F 2 FLUX S i 0 2 40 w / o (constant) A - 4340 WELD METAL O - 1010 WELD METAL 0.12 UJ CO LU 3 z 0 x o ,1010 LU C3 Z 0.08 - LU 2 LU 2 LU 4340 0.04 "AJ L 10 20 30 CaF2 IN THE FLUX (wt./%) l i i i L 50 40 30 MnO IN THE FLUX (wt.%) 0.0 L 60 40 J 20 Fig. 14 — Comparison of weld metal oxygen as a function of CaF2 additions to manganese silicate in submerged arc welding of AISI 1010 and 4340 steels. Comparative Effects of Flux Additions on AISI 1010, 1020 and 4340 Steel Weld Metal A c o m p a r i s o n of the effect of FeO a n d CaF2 additions t o a manganese-silicate w e l d i n g flux o n AISI 1010, 1020 a n d 4 3 4 0 steel w e l d metal c o m p o s i t i o n w a s m a d e in an e f f o r t t o study the effects o f the alloying elements present in the AISI 4 3 4 0 steel o n the flux-metal reactions. F u r t h e r m o r e , the metal elemental c o n t e n t (wt-%) w a s p l o t t e d as a f u n c t i o n of additions t o the flux (wt-%) at the expense of M n O . T h e silica c o n t e n t of the flux w a s held constant at 40 w t - % . The c o m p a r a t i v e effects of additions o f CaF 2 t o t h e flux o n AISI 1010 and 4 3 4 0 steel will b e discussed in the f o l l o w i n g section, f o l l o w e d by the effect of F e O additions t o t h e flux. CaF2 Flux Additions T h e CaF2 additions t o a manganese-silicate w e l d i n g flux at the expense of the M n O appears t o have a small e f f e c t o n the c a r b o n c o n t e n t of t h e w e l d in the AISI 1010 steel plate o v e r the flux c o m p o s i t i o n range studied, as s h o w n in Fig. 13. The w e l d metal silicon c o n t e n t rem a i n e d fairly constant at 0.35 w t - % f o r the AISI 1010 steel w e l d s , similar t o the b e havior seen f o r AISI 4 3 4 0 steel in Fig. 2. A significant difference in w e l d metal o x y g e n c o n t e n t can be seen in Fig. 14 c o m paring the AISI 1010 steel w e l d s t o the AISI 120-sl M A R C H 1990 50 40 30 MnO IN THE FLUX (wt.%) Fig. 15 - Comparison of weld metal manganese as a function of CaF2 additions to manganese silicate in submerged arc welding of AISI 1010 and 4340 steels. 4340 steel w e l d s , w i t h the AISI 1010 steel w e l d s having the higher o x y g e n c o n t e n t . The w e l d metal o x y g e n w a s apparently g e t t e r e d in t h e w e l d p o o l b y an alloying addition in t h e AISI 4340 steel, a l t h o u g h for the case of t h e CaF 2 flux additions it w a s o b s e r v e d that losses of c h r o m i u m , nickel and m o l y b d e n u m w e r e minimal. This raises the possibility that c a r b o n a n d o x y gen partition m a y be c o n t r o l l e d by a C O reaction, since the decrease o f o x y g e n e x p e r i e n c e d b y the AISI 4 3 4 0 a n d 1010 steel w e l d s varied a c c o r d i n g t o the c a r b o n change. For t h e 1010 steel w e l d s , the d e crease in o x y g e n c o n t e n t w i t h CaF 2 additions c o r r e s p o n d s t o an increase in the c a r b o n c o n t e n t , as o b s e r v e d in Figs. 13 and 14, respectively. T h e 4 3 4 0 steel w e l d s , o n the o t h e r h a n d , s h o w e d constant carb o n a n d o x y g e n c o n t e n t s (Figs. 13 a n d 14) except f o r the original d r o p in o x y g e n for the 5 w t - % CaF2 a d d i t i o n . Since n o c o r r e s p o n d i n g change w a s f o u n d in the w e l d c a r b o n c o n t e n t , it m a y b e speculated that the extra o x y g e n f o u n d in the w e l d c o r r e sponds to the eutectic M n O - S i 0 2 flux. In general, the w e l d metal manganese c o n t e n t of the AISI 1010 steel w e l d s remained fairly constant, as s h o w n in Fig. 15. In a d d i t i o n , a decreasing t r e n d w a s o b s e r v e d w i t h increasing flux additions in w e l d metal manganese c o n t e n t f o r the AISI 4 3 4 0 steel w e l d s , as seen in Fig. 15, b u t is difficult t o quantify d u e t o the scatter in t h e results. FeO Flux Additions C a r b o n c o n t e n t s in b o t h t h e AISI 1020 a n d 4 3 4 0 steel w e l d s w i t h additions o f FeO t o t h e flux are s h o w n in Fig. 16. T h e a m o u n t o f t h e w e l d metal c a r b o n w a s constant as a f u n c t i o n of flux c o m p o s i t i o n . The w e l d metal o x y g e n c o n t e n t increased w i t h increasing FeO additions as s h o w n in Fig. 17, f o r b o t h steel w e l d metals. The delta values f o r o x y g e n suggest a transfer o f o x y g e n t o b o t h the AIS11020 a n d 4 3 4 0 steel w e l d metal. M o r e o x y g e n was transf e r r e d t o the AISI 1020 steel w e l d p o o l than t o t h e AISI 4340 steel w e l d p o o l . T h e r e w a s a significant d i f f e r e n c e b e t w e e n w e l d metal o x y g e n contents for the AISI 1020 and 4340 steel w e l d s w i t h b o t h CaF2 and FeO additions t o the flux. This is b e l i e v e d t o be d u e also t o the oxidation of c h r o m i u m in the AISI 4340 steel welds made with the Si02-MnO-FeO fluxes. T h e loss of c h r o m i u m for the Si02M n O - F e O flux system as seen in Fig. 10 w o u l d t e n d t o c o n f i r m this suggestion. In b o t h the AISI 1020 a n d 4 3 4 0 steel w e l d s , t h e w e l d metal silicon r e m a i n e d fairly constant w i t h increasing additions o f FeO in t h e flux, as seen in Fig. 18. These results suggest that the pyrometallurgical reactions involving silicon are the same. T h e delta values f o r silicon indicate that m o r e silicon w a s transferred f r o m the flux t o t h e w e l d metal f o r t h e AISI 1020 steel c o m p a r e d t o the AISI 4 3 4 0 steel, as seen
u.o i 1 1 I I 0.8 I T" SK32 - MnO - FeO FLUX Si02 40 w/o (constant) A - 4340 WELD METAL 1020 WELD METAL o i 0.6 * z o m tr O h " M r t O - F e O FLUX 4 0 w / o (constant) 4 3 4 0 WELD METAL 1020 WELD METAL 0.6 — 0.6 0.8 T" T Sr02 SK32 A A O " s z o o LU 4340 2 A -A 0.4 l?i § u 2 AA A A A LU O 0.4 - 0.4 m 1020 & 4 3 4 0 q A Q o o z -I LU -A 3 3 0.2 ; 1020 0.2 o / DELTA SILICON O 0 o o y. o r A 0.0 i 60 I 10 l 50 I 20 FeO IN THE l I I I 30 FLUX ( w L % ) l l 40 MnO IN THE FLUX L 30 A 0.0 t 40 I 0 I 10 A - I I J * 20 30 FeO IN THE FLUX (wt.%) 40 -0.1 20 L (wt.) L J L 60 Fig. 16 - Comparison of weld metal carbon as a function of FeO additions to manganese silicate in submerged arc welding of AISI 1020 and 4340 steel. 50 40 30 20 MnO IN THE FLUX (wt.%) Fig. 18 — Comparison ot weld metal silk on as a function to manganese in submerged silicate arc welding of FeO additions of AISI 1020 and 4340 steels. 0.1a I T 1.6 S i 0 2 - M n O - F e O FLUX Si02 4 0 w / o (constant) A - 4 3 4 0 WELD METAL O - 1020 WELD METAL I 1 1 1 SKD2 - MnO - F e O FLUX SKD2 4 0 w / o ( c o n s t a n t ) A - 4 3 4 0 WELD METAL 1020 WELD METAL o X 0.12 1.2 1020 ztu a 1020 z X O t- o z 008 4340 Ul (- 2 0.8- LU tu 3 0.04 0.4 0.0 10 60 30 (wt.%) 40 40 30 20 THE FLUX (wt.%) 20 FeO IN THE FLUX 50 M n O IN 10 Fig. 17 — Comparison of weld metal oxygen as a function of FeO additions to manganese silicate in submerged arc welding of AISI 1020 and 4340 steels. l J 20 30 FeO IN THE FLUX (wt%) J 0.0 L 60 J L 50 I I 40 MnO IN THE Fig. 19 — Comparison ditions to manganese 4340 steels. I L 30 40 J J 20 FLUX (wt.%) of weld metal manganese as a function of FeO adsilicate in submerged arc welding of AISI 1020 and WELDING RESEARCH SUPPLEMENT 1121-s
0.6 T Si02 Si02 A O " S - 1 1 w h i l e the manganese level remains c o n stant f o r the S i 0 2 - M n O - C a F 2 flux system. M e a n w h i l e , the w e l d s p r o c e s s e d w i t h t h e S i 0 2 - M n O - F e O flux system o n the AISI 1020 and 4 3 4 0 steel plates, s h o w constant c a r b o n c o n t e n t s despite increasing o x y gen levels. A p p a r e n t l y , t h e excess o x y g e n oxidizes manganese in the 1020 steel welds and b o t h chromium and manganese in 4 3 4 0 steel w e l d s . T h e w e l d s processed w i t h the Si02M n O - C a O flux system o n AISI 4 3 4 0 steel, s h o w constant c a r b o n , o x y g e n a n d m a n ganese c o n t e n t s w h i l e t h e same fluxes caused the greatest o x i d a t i o n o f the alloying elements f o r these w e l d s . 1 - MnO -FeO FLUX 40 w/o (constant) 4340 WELD METAL 1020 WELD METAL 0.4 UJ 03 UJ Z o ? 2 0.2 -1020 & 4340 § 3 UJ Acknowledgment T h e authors a c k n o w l e d g e and a p p r e c i ate the research s u p p o r t o f the U n i t e d States A r m y Research O f f i c e . 0.0 Fig. 20 — Comparison of delta weld metal manganese as a function of FeO additions to manganese silicate in submerged arc welding of AISI 1020 and 4340 steels. References -0.2 60 in Fig. 18. These results suggest that silicon is influenced by the alloying elements in the AISI 4 3 4 0 steel. The o x y g e n c o n t e n t of the AISI 4 3 4 0 steel w e l d s w i t h increasing FeO additions t o the flux d i d increase, w h i l e the manganese c o n t e n t decreased. H o w e v e r , the c a r b o n a n d silicon c o n t e n t r e m a i n e d c o n stant w i t h increasing flux additions. This suggests that t h e FeO a d d i t i o n in the flux w a s controlling the o x y g e n reaction. In Fig. 19, w e l d metal manganese c o n t e n t is seen t o h a v e d e c r e a s e d as t h e F e O flux additions increased. T h e AISI 1020 steel w e l d s d i d have a higher manganese c o n t e n t . This result is e x p e c t e d since the AISI 1020 w e l d i n g w i r e has t w i c e t h e manganese c o n t e n t of the AISI 4340 w e l d ing w i r e . T h e identical manganese transfer b e h a v i o r s h o w n in Fig. 20 f o r b o t h steels suggests that t h e same controlling reactions are w o r k i n g . Even t h o u g h the filler w i r e had different manganese c o n t e n t s or activities, the manganese reaction p r o c e e d e d t o the same d e g r e e o f c o m p l e tion. T h e w o r k o f b o t h G r o n g a n d Christensen (Ref. 10) and Chai and Eagar (Ref. 11) a t t r i b u t e d manganese losses t o e v a p o r a t i o n . In this investigation, manganese loss was o b s e r v e d b o t h in t h e AISI 1020 a n d 4 3 4 0 steel w e l d s w i t h F e O flux a d d i - 122-s MARCH 1990 J L 20 30 FeO IN THE FLUX (wt.%) J I I I I 50 40 30 MnO IN THE FLUX (wt.%) A10 L 20 tions greater than 20 w t - % as s h o w n in Fig. 20. N o t e in Fig. 9 that f o r AISI 4 3 4 0 w e l d s the manganese c o n t e n t d i d decrease w i t h decreasing a m o u n t s of M n O in the flux w i t h b o t h the FeO and CaF2 flux additions. H o w e v e r , it is i m p o r t a n t t o r e m e m b e r that n o decrease in manganese w a s o b served f o r the C a O flux additions. Loss of nickel, c h r o m i u m and m o l y b d e n u m in the AISI 4340 steel w e l d s w i t h a d ditions of C a O in t h e flux d e m o n s t r a t e s the n e e d t o exercise care in selection o f a flux in w e l d i n g alloy steels. Loss o f c a r b o n should also b e c o n s i d e r e d in w e l d i n g l o w - c a r b o n a n d alloy steels. W i t h heattreatable alloy steels such as AISI 4 3 4 0 steel, t h e c o n t r o l of w e l d metal c o m p o s i t i o n w o u l d b e e v e n m o r e i m p o r t a n t since the desired final m i c r o s t r u c t u r e is m a r t e n site, w h i c h is influenced b y b o t h alloy c o m p o s i t i o n a n d thermal experience. Summary The additions o f CaF2, C a O a n d F e O t o a manganese-silicate flux a n d their effects o n t h e e l e m e n t transfer f r o m t h e slag t o t h e w e l d metal and vice versa can b e qualitatively explained, in s o m e cases, using t h e r m o d y n a m i c data. The c a r b o n / o x y g e n partition appears t o be c o n t r o l l e d b y a C O reaction in the 1010 steel w e l d s . 1. Christensen, N. 1949. Metallurgical aspects of welding mild steel. Welding Journal (28): 373-s. 2. Chai, C. S„ and Eagar, T. W. 1981. Slagmetal equilibrium during submerged arc welding. Met. Trans. 12B, p. 539. 3. Blander, M „ and Olson, D. L. 1984. Thermodynamic and kinetic factors in the pyrochemistry of subme
AISI 4340 o.oa 20 30 FLUX ADDITION (wt.%) J I I I 60 50 40 30 Mn O IN THE FLUX (wt.%) 20 Fig. 3 — Delta weld metal silicon as a function of flux additions to a man ganese silicate flux used in submerged arc welding of AISI 4340 steel. A -Si02-MnO-CaF2 FLUX O -Si02-MnO-CaO FLUX AISI 4340 -Si02-MnO-FeO FLUX Si02 40 w/o (constant) !J 0.06 z
the welding processes most often used in today's industry including plasma arc cutting, oxyfuel gas cutting and welding, Gas Metal Arc Welding (GMAW), Flux-Cored Arc Welding (FCAW), Shielded Metal Arc Welding (SMAW), and Gas Tungsten Arc Welding (GTAW). Flat welding positions and basic joints will be practiced. Pipe and tube welding
6.3 Mechanised/automatic welding 114 6.4 TIG spot and plug welding 115 7 MIG welding 116 7.1 Introduction 116 7.2 Process principles 116 7.3 Welding consumables 130 7.4 Welding procedures and techniques 135 7.5 Mechanised and robotic welding 141 7.6 Mechanised electro-gas welding 143 7.7 MIG spot welding 144 8 Other welding processes 147 8.1 .
seam butt welding resistance butt welding flash butt welding resistance butt welding shielded unshielded other process plasma laser resistance butt welding inert gas welding submerged arc welding atomic hydrogen shielded metal arc welding (coated electrode) esepl w w w . e u r e k a e l e c t r o d e s .
3. Classification of Underwater Welding Underwater welding may be divided into two main types: a) Wet welding b) Dry welding Fig. 3.1 Classification of underwater welding 3.1 Wet welding 3.1.1. Wet welding with coated electrode Wet welding is performed at ambient pressure with the welder-diver in the water and no physical barrier
Note: CSA W59-18 Welded Steel Construction (Metal Arc Welding) may be referenced when joining stainless steel to carbon steel. This WPS will be presented to the Canadian Welding Bureau (CWB) along with the related WPDS for approval. Welding Procedure The welding shall be done Semi-automatically using the Flux Cored Arc Welding (FCAW) process.
asless welding using a flux-cored wire is a MIG welding process that relies on a continuous, tubular wire feed. Gasless wire welding was originally designed as a replacement for stick welding, mostly for use out-side where protecting gas-es could be blown away by the wind and hig
Air Carbon Arc (CAC-A) Cutting and Gouging TIG (GTAW) Welding Stick (SMAW) Welding Engine Driven Welding Generator With Optional Equipment: MIG (GMAW) Welding Flux Cored (FCAW) Welding. Miller Electric manufactures a full line of welders and welding related equipment.
I. DNA, Chromosomes, Chromatin, and Genes DNA blueprint of life (has the instructions for making an organism) Chromatin uncoiled DNA Chromosome coiled DNA You have 46 chromosomes or 23 pairs in the nucleus of each body cell. o 23 from mom and 23 from dad Gene a segment of DNA that codes for a protein, which in turn codes for a trait (skin tone, eye color, etc); a gene is a stretch of .
