Laser Beam Welding of HY80 and HY100 Steels Using Hot Welding Wire Addition

SUPPLEMENT TO THE WELDING JOURNAL, JUNE 1992 Sponsored by the American Welding Society and the Welding Research Council

Good impact properties are attained in high-strength steels welded with the laser beam process using a preheated filler metal

BY R. H. PHILLIPS AND E. A. METZBOWER

ABSTRACT. Laser beam welds incorpo proved using a fast wire feed compared welding in the heterogeneous mode rating a hot welding wire filler metal ad to a slow wire feed. compared to the autogenous mode can dition technique have been successfully be considered as follows: produced in HY80 and HY100 steels. Introduction 1) Confers the ability to alter the Plate thicknesses of 1 3 and 26 mm were chemical composition and thus the mi welded by this technique in these ex Laser beam welding is a high produc crostructure of the weld metal. This in periments. tivity process that is traditionally used turn can result in improved mechanical This evaluation included radio- in the autogenous mode {i.e., no filler properties of the weld metal, particu graphic and metallographic examina metal is added to the weld pool). How larly notch toughness. It can also result tions, hardness traverses, Charpy V- ever, it can clearly be perceived that on in improved resistance to weld metal so notch tests over the temperature range specific occasions there would be dis lidification cracking. -68° to 20°C and fractographic exami tinct advantages and greater flexibility 2) Results in larger fit-up tolerances. nations. in deploying laser beam welding in the 3) Affords the opportunity for deposit Hardness traverses across the hot wire heterogeneous mode (i.e., by use of filler ing high-quality multipass welds with addition welds showed a significant re metal additions to the weld pool). Sev reduced porosity, compared to autoge duction in weld metal hardness com eral examples of laser beam welding in nous weldments. pared to the autogenous welds. The re corporating cold welding wire feed have In the specific cases of HY80 and duction in hardness was greater for the been reported in the literature in recent HY100 steels, the relatively high carbon "fast" wire addition welds compared to times (Refs. 1-3). (0.1 5-0.1 8 wt-%) and alloy content of the "slow" wire addition welds. The main advantages of laser beam the steels, together with the fast cooling The hot wire feed speed also had a rates associated with autogenous laser concomitant effect on weld metal mi beam welding, ensures the formation of crostructure. The slow wire feed speed untempered martensitic microstructures resulted in a mixed martensite-bainite in the weld metal. This can lead to the microstructure, whereas fast wire feed KEY WORDS formation of weld metal with poor notch speed produced an acicular ferrite mi ductility (Refs. 4, 5). Feed Speed crostructure. By way of comparison, the weld Charpy tests showed that hot wire ad Hardness Testing metal deposited using conventional arc dition significantly improved weldment Hot Welding Wire welding of HY steels characteristically toughness compared to autogenous Hot Wire Additions has a relatively low carbon level rang welds at the plate sulfur level investi HY80 ing from 0.05 to 0.08 wt-%. Under ap gated (0.01 2 wt %) for both HY80 and HY100 propriate welding conditions, this leads HY100 steels. Toughness was further im- Laser Beam Welding to the formation of an acicular ferrite mi Metallography crostructure with a concomitant high Microstructure R. H. PHILLIPS is with the Materials Research toughness profile. Laboratories, Melbourne, Australia, and E. Steel Plate The two methods of filler metal addi A. METZBOWER is with the Naval Research tion that appear to have the best poten Laboratory, Washington, D.C. tials for use with laser beam welding are

WELDING RESEARCH SUPPLEMENT I 201-s FOCUSING a plane mirror into a downward-facing concave mirror with a focal length of MIRROR 750 mm (29.5 in.) to provide welding conditions in the flat position. The plates to be welded were 150 X 300 mm (6 X 12 in.) thick, resulting in a 300 X 300- mm (12X12-in.) thick weldment. A schematic diagram of the worksta tion including the hot wire feed unit is shown in Fig. 2A and in greater detail in Fig. 2B. The welds were made by mov ing the workpiece on a traversing table under the stationary laser beam. The REFLECTING angle between the normal to the plate and the laser beam was approximately FLAT MIRROR 3 deg. Helium gas was used for plasma suppression as well as general area shielding of the weld. Plasma suppression was achieved by GAS SHIELD AND directing a jet of helium gas through a W//7rWA PLASMA SUPPRESSION 2-mm (0.08-in.) diameter stainless steel tube (hypo tube) at the point where the WORK focused laser beam would impinge upon the plate surface. The hypo tube was set behind the laser beam at an angle of Fig. 1 — Schematic diagram of beam focusing arrangements and workstation. about 45 deg and was coplaner with the welding direction. The flow rate of the helium gas was approximately 3 L/min welding wire addition or metal powder The paper concentrates on the 3 addition. Charpy V-notch specimens since it has (1.4 ft /h)as determined by a gas flow Of these, welding wire addition ap been demonstrated that the attainment meter calibrated for air. pears to hold the best potential, both of weldments with adequate mechani Precise alignment of the joint to be from the viewpoint of metallurgical cal properties in laser beam welds of welded was made using a helium-neon quality of the weld and also productiv HY80 and 100 is not a problem (Refs. (He-Ne) laser, which was coincident ity. For instance, oxygen and hydrogen 5,6). with the C02 laser beam. Prior to weld pickup in the weld metal would be far ing, tack welds were made at both ends more of a problem for welding with Experimental Procedure of the plate to be welded, which pre metal powders than for welding with and Materials vented relative movement between the wire. two plates due to expansion and con In the experimental work reported, a A 1 5-kW continuous wave, carbon traction of the plates during welding. hot wire addition technique was used dioxide laser in the unstable resonator A longer focal length mirror of 750 so that most of the energy from the laser mode was used for these experiments mm was used for the hot wire addition beam was used to establish and main (Ref. 7). A schematic diagram of the laser experiments compared to a 500-mm tain the keyhole rather than being par beam focusing arrangements is shown (20-in.) focal length mirror for the auto tially dissipated in melting the filler in Fig. 1. The horizontal output beam genous laser beam welding experiments metal. from the laser was reflected upward by (Ref. 4). It was necessary to use the

Hot wire designed to skid along base of groove into path of laser beam Laser beam

Welding wire Gas lens for He area shield

— Solidified weld metal

Plasma suppression hypo needle He gas

He backing gas

Fig. 2 — A — Schematic diagram of experimental setup for laser beam welding with hot welding wire feed; B — detail of hot wire filler metal addition.

202-s I JUNE 1992 Table 1—Composition of Experimental Materials

Chemical Composition wt-%

C s P Mn Si Ni Cr Mo Cu Al

13-mm-thick HY80 0.16 0.014 0.0007 0.32 0.18 2.32 1.41 0.29 0.13 0.03 Plate 13-mm-thick HY100 0.16 0.016 0.005 0.26 0.21 2.66 1.47 0.41 0.15 0.02 26-mm-thick HY80 0.15 0.002 0.005 0.31 0.31 2.24 1.37 0.28 0.17 0.05

Welding 1.2-mm-diameter 0.065 0.004 0.006 1.50 0.21 2.10 0.10 0.47 0.04 Wire Airco AX90

As- 13-mm HY80 with HWA

(a) HWA is hot wire addition.

longer focal length mirror to enable the marily directed at establishing the most of 1 3 kW; and 2) a travel speed of 8.5 physical location of the hot wire so that appropriate edge preparation and weld mm/s (20 in./min). the incoming laser beam would not im ing conditions for the root pass. pinge upon it. Although the longer focal The compositions of all experimen Results and Discussion length mirror has the advantage of hav tal steels and the welding wire are shown ing a greater depth of field, it has the dis in Table 1. Welding Parameters and Characteristics advantage of having a larger spot diam Two edge profiles were used in the eter at the focal point and hence a some experimental work (stepped and V- Good quality welds with acceptable what reduced power density. groove). In addition, two wire feed penetration and top and bottom bead The hot wire feed unit consisted of a speeds were also used, (a slow speed of formation were produced at the slow power transformer, a variable speed wire 145 mm/s, 5.7 in./min, and a fast speed wire feed regardless of whether a feed unit and the hot wire torch. The of 425 mm/s, 16.7 in./min). Full pene stepped or V-groove preparation was welding wire used in these experiments tration welds were produced in both used. Radiographic inspection of the was 1.2-mm (0.045 in.) diameter Airco HY80 and HY100 steels. The laser beam welds showed that both weld metal so AX90 to MIL 100 SI specification, and welding parameters used in these exper lidification cracking and porosity were of the composition shown in Table 1. iments were as follows: 1) a power input markedly reduced compared to autoge- The wire was heated resistively with the extension from the contact tip being set EDGE PROFILES TRIALLED : 13mm THICK PLATE HY STEELS at 40 mm (1.6 in.). Before commencing laser beam welding experiments, the power settings on the hot wire feed trans former were adjusted so that melting was just occurring at the wire tip and a molten bead would be deposited on the 3.2 plate surface but not welded to it.The 6.5 hot wire torch was set at an angle of 55 deg to the plate so that the wire inter sected the bottom groove of the plate 6 6.5 to 8 mm (0.24 to 0.31 in.) ahead of the laser beam and then skidded into the EDGE PROFILE STEPPED V V beam path as shown in Fig. 2. The experimental work was con hot wire feed 145mm/sec 145mm/sec 425mm/sec ducted in two stages: speed 1) Single-pass welds in 1 3-mm (0.5- good poor in.) thick HY80 and HY1 00 plates incor plasma control good porating the hot wire addition. weld appearance acceptable top & acceptable top & acceptable top bead, 2) Multipass welds incorporating the bottom bead bottom bead unacceptable bottom hot wire addition in 26-mm (1-in.) thick formation formation bead lack of penetration HY80 plate. In Stage 1 of the work, two edge valid CVN YES YES NO profiles and two wire feed speeds were utilized. These are illustrated in Fig. 3. Only a limited amount of work was Fig. 3 — Summary of edge profiles used. carried out in Stage 2 and this was pri

WELDING RESEARCH SUPPLEMENT I 203-s Fig. 4 — Comparison of weld bead profiles for laser butt joint welds in 13-mm-thick HY80. A - Autogenous; B — hot welding wire addition at 145 mm/s; C — hot welding wire addition at 425 mm/s. nous welds with a similar sulfur level trol was observed with weld quality the the weld metal decreases with increas (Ref. 8). From an operational viewpoint, result. ing wire feed speed while the man the plasma plume above the plate sur A comparison of weld bead profiles ganese and silicon content is increased. face was readily controllable during obtained for autogenous laser beam This is a result of the mixing of the weld welding although it was somewhat more welding and laser beam welding with metal and the base plate. At the higher sensitive to procedural variations than the slow and fast wire feed speed is wire feed, more welding wire is incor for autogenous welding. shown in Fig. 4A, 4B and 4C. As ex porated into the fusion zone. At the fast wire feed speed, however, pected, it can be seen that the weld The weld metal carbon level is of par significant problems were encountered nugget size progressively increases from ticular importance and is progressively with plasma control, and poor quality autogenous welding through to the slow reduced with increasing wire feed welds usually resulted. In this case, al and fast wire feed speeds. It can be seen speed. From a plate carbon level of 0.16 though top bead formation was gener from Fig. 4C that the fast wire feed has wt-% C, the weld metal carbon level ally acceptable, there was frequently in resulted in the formation of an undesir drops to 0.010 wt-% C for the slow wire complete joint penetration and unac able wine glass weld nugget profile. This feed and further to 0.06 wt-% C for the ceptable bottom bead profile. This was problem would probably be alleviated fast wire feed speed. This level is simi probably a result of an incorrectly de by using a different weld groove configu lar to that usually encountered with the signed edge preparation. In particular, ration, e.g. a stepped profile with a conventional arc welding of HY steels. it appeared there was insufficient vol greater volume capacity. In a similar manner, the sulfur level is ume designed into the weld groove and progressively reduced with increasing weld overfill resulted, which in turn Chemistry wire feed speed from 0.014 wt-% for the made plasma control more difficult. The chemical compositions of all HY80 plate to 0.009 wt-% for the slow In order to obtain valid Charpy-V plate materials, welding wire and resul wire feed speed and further to 0.005 wt- notch (CVN) results for the fast wire feed tant weld metal is shown in Table 1. Pre % for the fast wire feed speed. It can thus situation, a further series of welds was vious work (Ref. 8) has indicated that be seen that carbon and sulfur content made in 26-mm (1 -in.) thick HY80 plate. the composition of the fusion zone of of the fusion zone is progressively de During these experiments, the weld autogenous weldments is essentially that creased with increasing wire feed speed through the dilution effect of the filler metal was generally constrained within of the base plate. It can be seen that the metal. the weld groove and good plasma con carbon, chromium and sulfur content of

Fig. 5 — Comparison of weld metal microstructures. A — Auto genous; B — hot welding wire ad dition at 145 mm/s; C — hot weld ing wire addition at 425 mm/s.

204-s I JUNE 1992 Microstructure » Hardness profile fo autogenous weld Clear differences are evident in the photomicrographs of the weld metal mi crostructures shown in Fig. 5. For the HOT WIRE FEED HOT WIRE FEED autogenous laser beam weld (Fig. 5A), AUTOGENOUS t the microstructure is primarily untem AT 145mm/sec AT 425mm/sec [ HAZ WELD HAZ | pered martensite. The slow wire feed | HAZ | METAL weld (Fig. 5B) results in a mixed martensite/bainite microstructure, and the fast // •• / • •i \ wire feed weld (Fig. 5C) results in a mi • 1 crostructure that is primarily acicular fer I * • rite. The differences are the same for / * . 1 • both the HY80 and HY1 00 weldments. A A '•••• -...\— It should be noted that acicular ferrite is the preferred weld metal microstructure Distance from Weld Distance from Weld Distance from Weld for optimum toughness when HY80 and Centre Line (mm) Centre Line (mm) Centre Line (mm) HY1 00 are welded by conventional arc Fig. 6 — Comparison of hardness profiles across HY80 laser beam weldments. processes. Clearly, there is a critical pa rameter, based on the volume fraction of consumable wire in the weld metal Charpy V-Notch Results sulfur levels of 0.012 wt-%. It can be and the cooling rate, that must be at seen that the toughness improvement is tained before an acicular ferrite mi Charpy V-notch (CVN) tests were much more dramatic in the case of the crostructure is produced. conducted on slow wire feed speed HY100 welds, as the autogenous HY100 welds (145 mm/s) made in 13-mm-thick weld has a significantly lower toughness Hardness Profiles HY80 and HY100, and fast wire feed than the autogenous HY80 weld. speed welds, (425 mm/s) made in 26- Clearly, the introduction of filler metal The results of hardness traverses mm-thick HY80 steel, covering the tem has almost completely negated the un along the weldment cross-sections of the perature range -68° to 20°C (-90° to known factor causing the difference in three laser beam welds are shown in Fig. 68°F). The notches were located in the toughness between autogenous HY80 6. For the autogenous welds in HY80 fusion zone. These results are shown in and HY100 welds. and HY100, it can be seen there is a high Fig. 7 along with previous autogenous The HY80 welds produced using the hardness plateau of about 450 HV across laser beam weld results in high-sulfur slow wire feed speed met the minimum the HAZ and weld metal. For the hot (0.012 wt-%) HY80 and HY100 steels. U.S. Navy CVN requirement at -51 °C wire addition welds, the hardness profile Also included for comparison is the U.S. (-60°F), but did not quite meet the re alters significantly to become bimodal, Navy minimum CVN (Ref. 9) require quirement at -1 8°C (0°F), being about with the maximum hardness of about ment for HY80 and HY100 weld metal. 5 J below the requirement. As these re 450 HV being achieved in the coarse All data points are the average value of sults represented the first iteration of ex grained HAZ but reducing to lower lev three tests. perimental work in this area, it could els in the weld metal. The biggest reduc It can be seen from Fig. 7 that the CVN confidently be anticipated that the U.S. tion in weld metal hardness occurs for values for both HY80 and HY100 welds Navy minimum CVN requirements the fast wire feed speed where the aver produced using hot wire feed at the slow would be met with some fine tuning of age weld metal hardness was 290 HV wire feed of 145 mm/s are very similar the experimental parameters. By com compared to a weld metal hardness of over the entire range tested and show a parison, the HY80 welds produced using 350 HV for the slow wire feed speed and significant improvement compared to the fast wire feed speed of 425 mm/s in 450 HV for the autogenous weld. autogenous welds in these steels with 26-mm plate showed a significant im-

WELDING RESEARCH SUPPLEMENT I 205-s 200 jfc MINIMUM U.S. NAVY REQUIREMENT most of it was concentrated on the in vestigation of root passes. HWA is Hot Wire Addition Welding Sequence and Edge Preparation • HY80 HWA AT 425 mm/sec (26mm plate) • Hi S HY80 HWA AT f45mm/sec 150 • Hi S HY100 HWA AT 145mm/sec The overall concept of sequencing O Hi S HY80 Autogenous the multipass laser beam welding exper A Hi S HYtOO Autogenous iments incorporating hot wire addition 03 into the molten weld pool is shown ZJ schematically in Fig. 9. Essentially, this o involved depositing a full root penetra > 100 tion pass using a focused beam and hot o wire addition, i.e., a standard keyhole- cc type weld. It was proposed that subse LU quent passes would involve "out of LU HY100 focus" welding and hot wire addition. The main reason for attempting out of 50 focus welding was to substantially re duce excessive porosity problems, which are traditionally encountered when using a focused beam in a non- penetrating situation. The objective was to obtain a U-shaped weld pool, as op J_ _L _l_ posed to the spike profile which char -60 -40 -20 0 20 acterizes focused beam welding. TEMPERATURE °C Two edge preparations were em ployed in these experiments, namely a Fig. 7 — Comparison of weld metal CVN results for laser beam welds using hot welding wire stepped edge profile and a double V- addition. groove profile. Both profiles incorpo rated butting root faces for the root pass. provement in CVN values over the en (SEM) and are shown in Fig. 8A, B and These are shown in Fig. 10. tire temperature range tested. These re C. The most outstanding difference be sults comfortably met U.S. Navy tough tween the SEMs is the proportion of mi Welding Characteristics and ness requirements. crovoid coalescence present on the frac- Weld Bead Profiles From the results presented, it is ap ture surface. Autogenous laser beam parent that the improvement in tough welds in HY80 and HY100 showed a First pass root welds incorporating a ness from autogenous through slow wire relatively low proportion of microvoid focused laser beam and the fast wire feed feed to fast wire feed is primarily due to coalescence; being 25% for HY80 welds speed of 425 mm/s were deposited in the changes in weld metal microstruc (Fig. 8A), and 20% for HY100 welds. For 26-mm-thick HY80 plate using both the ture from untempered martensite the slow wire feed welds in HY80 (Fig. stepped and double V-groove profile. through a mixed martensite bainite mi 8B), the proportion of microvoid coales The laser beam welding parameters used crostructure to acicular ferrite. cence increased to 70% and even higher in these experiments were 1) a power to 80% for the fast wire feed welds in input of 15 kW, and 2) a travel speed of Fractographic Examination of HY80—Fig. 8C. 8.5 mm/s. Broken CVNs The welding characteristics for the Multipass Welding in 26-mm HY80 Plate stepped profile groove weld were excel The fracture faces of all CVN speci lent, and plasma control presented no mens broken at -51 °C were examined Only a small amount of exploratory problem. During these experiments, the using scanning electron microscopy work was conducted in this area, and plasma appeared to be confined within

Fig. 8 — SEM comparison of weld metal fracture ap pearance (HY80 CVNs broken at -51°C) A — Au togenous; B — hot weld ing wire addition at 145 mm/s; C — hot welding wire addition at 425 mm/s.

206-s I JUNE 1992 the walls of the weld groove, a factor which probably assisted the plasma con trol greatly. A visual inspection of the root pass showed a very good bead appearance, with the root surface in particular being very uniform. Radiography of the weld however showed extensive centerline weld metal solidification cracking al though porosity was minimal. Metallo graphic sections were taken of both cracked and uncracked sections and these are shown in Fig. 11A and 11 B. In 4mm an attempt to overcome the solidification cracking, further experi Edge Profile First (Root) Second Pass Third Pass ments were conducted using a preheat Pass Full Focus Defocused Defocused of 150°C (302°F). However, radio- Key Hole Welding Laser Beam Laser Beam graphic inspection of these welds With Hot Wire With Hot Wire With Hot Wire showed that extensive solidification Addition Addition Addition cracking was still present and that pre heating did not appear to significantly Fig. 9 — Concept of sequencing multipass laser beam welding experiments incorporating a reduce the problem. hot welding wire addition. It was deduced that weld metal com position was not the most important fac tor promoting cracking as both the car •^ 5 —H bon level (0.08 wt-%) and the sulfur level (0.003 wt-%) were relatively low. 5 The main detrimental factors promoting * R R cracking were probably the relatively high strain imposed by the 26-mm plate on the 12-mm-deep weld, the high depth-to-width ratio of 2.2:1, the pri t \ 6.5 mary solidification direction, and finally, the amount of low melting point segregates. In this latter respect, it can be seen from Fig. 10B that in the top sec 6.5 tion of the weld where cracking occurs, the weld metal solidification front sweeps laterally toward the centerline 6.5 with no upward sweep so that all low t \ melting point segregates are concen trated along a plane of weakness in the centerline. Lower down the weld, how ever, the solidification front tends to Stepped Edge Profile Double V Profile sweep upward, which probably has the measurements in mm effect of dispersing the low melting point segregates to some extent. Fig. 10 — Edge preparations used for root pass experiments in 26-mm HY80 plate. In the case of the double V-groove, acceptable full penetration welds were

WELDING RESEARCH SUPPLEMENT I 207-s Fig. 11 — Left — Weld bead profile for root pass in stepped weld groove in 26-mm plate using Fig. 12 — Weld bead profile for a root pass a hot welding wire addition at a feed rate of 425 mm/s, no solidification cracking; right— weld in a double V-groove on 26-mm plate using bead profile of root pass in a stepped square-groove in 26-mm plate using a hot welding wire a hot welding wire addition with a feed rate addition at a feed rate of 425 mm/s, centerline weld metal solidification cracking is evident. of 425 mm/s. produced, although the welding char that encountered in autogenous laser the main problem encountered in de acteristics were not as stable as for the beam welds in HY80 and HY100 plates positing the root pass. stepped square-groove. Since plasma at similar sulfur levels (0.014 wt-%). control was somewhat more difficult, ra Weld metal CVN values for the hot References diographic examination showed only wire filler metal addition welds in both minor porosity, although some intermit HY80 and HY100 were significantly 1. Watson, N.M.I 985. Welding Institute Research Bulletin, 26, p. 308. tent weld metal solidification cracking higher than those obtained for autoge nous laser beam welds at similar sulfur 2. Arata, Y., Maruo, H., Miyamoto, I., and was present. A macrosection of a com Nisho, R. 1986. Electron and Laser Beam pleted weld is shown in Fig. 12. It is par levels. Toughness was further improved Welding. International Institute of Welding, ticularly interesting to note that the sin using a fast wire feed speed of 425 mm/s p. 159. gle-pass cross-section is 20 mm deep compared to a feed speed of 145 mm/s. 3. Banas, C. 1986. Industrial Laser Annual not counting the extra 2 mm of weld For the welds investigated, the weld Handbook, Pennwell. metal with no sidewall fusion at the bot metal microstructure was the most im 4. Phillips, R. H., Moon, D. W., and Metz tom of the bead. It can be seen that a portant factor determining toughness. bower, E. A. 1986. Proceedings of the 34th completed weld in 26-mm plate could The weld metal microstructure was it National Welding Conference. Adelaide, p. 387. easily be made in two passes and that a self primarily determined by the wire 5. Moon, D. W., Metzbower, E. A., and feed speed as it affects dilution. In this low-penetration, high-speed weld could Phillips, R. H. 1 985. Laser Welding, Machin be used for the second pass. respect, welds produced using the fast ing and Materials Processing. San Francisco, wire feed speed resulted in an acicular p. 3. Conclusions ferrite microstructure, whereas welds 6. Moon, D. W., and Metzbower, E. A. produced using the slow wire feed speed 1983. Lasers in Materials Processing. Los An Single-pass laser beam welds incor resulted in a mixed martensite/bainite geles, p. 248. porating a hot wire filler metal addition microstructure. By contrast, autogenous 7. Hettche, L. R., Metzbower, E. A., Ayres, technique have been successfully pro laser beam welding of HY80 and HY100 ). D., and Moore, P. C. 1981. Naval Research Reviews. Office of Naval Research, 33(2):4. duced in 13-mm-thick HY80 and HY100 resulted in an untempered martensitic microstructure. 8. Metzbower, E. A., and Denney, P. E. plate. 1986. First International Conference on The level of weld metal solidification In the multipass laser beam welding Power Beam Technology. Brighton, p. 317. cracking and porosity in the single-pass of 26-mm-thick HY80 incorporating hot 9. Military specification. 1987. Electrodes hot wire addition welds in 1 3-mm HY80 wire filler metal additions, weld metal and Rods — Welding, Bare, Solid, or Alloy and HY100 was significantly less than solidification cracking was found to be Cored, Low Alloy Steel. MIL-E-237651 2D.

208-s I JUNE 1992