Gas Tungsten Arc Welding Handbook, 7th Edition Page 130 (132 of 320)

Copyright Goodheart-Willcox Co., Inc. 130 Gas Tungsten Arc Welding Handbook Solid Wires for HSLA Steel Per AWS 15.28 Classification Compositiona,b Characteristics, Applications C Mn Si P S Ni Cr Mo V Cu Cr-Mo ER80S-B2 0.07– 0.12 Use to weld 1/2 Cr-1/2 Mo, 1 Cr-1/2 Mo, 1-1/4 Cr-1/2 Mo steels for high- temperature and corrosive service and for Cr-Mo to carbon-steel welds. Lower carbon content improves resistance to cracking. Use where postweld heat treatment is not performed. Use for 2-1/4 Cr-1 Mo steel for high-temperature high-pressure piping and vessels. For all Cr-Mo-to-carbon-steel joints. Lower carbon content improves resistance to cracking. Use where postweld heat treatment is not performed. Use to weld HSLA steels and nickel steels up to 3-1/2%. Gives high strength and good toughness down to -100°F (-73°C). High Mn and Si contents reduce porosity. For single and multipass welding of carbon and low-alloy steels. Use on S-bearing (free machining) steel. Farm implements, auto parts, light-gauge steel, AISI 4130, T-1. High-strength, tough weld metal for critical welds. HY80, HY100 and higher-strength steels, structural applications for service as low as -60°F (-51°C). ER80S-B2L 0.05 0.40– 0.40– 0.025 0.025 0.20 1.20– 0.40– – 0.35 0.70 0.70 1.50 0.65 ER90S-B3 0.07– 2.30– 0.90– 0.12 2.70 1.20 ER90S-B3L 0.05 2.30– 0.90– 2.70 1.20 Ni steel ER80S-Ni3 0.12 1.25 0.40– 0.25 0.25 3.00– – – – – 0.80 3.75 Mn-Mo ER80S-D2 0.07– 1.60– 0.50– 0.025 0.025 0.15 – 0.40– – 0.50 0.12 2.10 0.80 0.60 Otherd ER100S-1 0.08 1.25– 0.20– – – 1.40– 0.30 0.25– 0.05 0.25 1.80 0.50 2.10 0.55 ER100S-2 0.12 1.25– 0.20– 0.010 0.010 0.80– 0.30 0.20– 0.05 0.35– 1.80 0.60 1.25 0.55 0.65 ER110S-1 0.09 1.40– 0.20– 1.90– 0.50 0.25– 0.04 0.25 1.80 0.55 2.60 0.55 ER120S-1 0.10 1.40– 0.25– 2.00– 0.60 0.30– 0.03 0.25 1.80 0.60 2.80 0.65 ERXXS-Gc 1.20– 0.40– 1.50 0.65 a. As manufactured. b. Total other elements, 0.50. c. Minimum 0.50 nickel, 0.30 chromium, or 0.20 molybdenum. d. Ti, Zr, Al, 0.10 each, except –G wires. Figure 8-2. The letters HSLA identify the steels as high-strength, low-alloy materials.

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Copyright Goodheart-Willcox Co., Inc. 130 Gas Tungsten Arc Welding Handbook Solid Wires for HSLA Steel Per AWS 15.28 Classification Compositiona,b Characteristics, Applications C Mn Si P S Ni Cr Mo V Cu Cr-Mo ER80S-B2 0.07– 0.12 Use to weld 1/2 Cr-1/2 Mo, 1 Cr-1/2 Mo, 1-1/4 Cr-1/2 Mo steels for high- temperature and corrosive service and for Cr-Mo to carbon-steel welds. Lower carbon content improves resistance to cracking. Use where postweld heat treatment is not performed. Use for 2-1/4 Cr-1 Mo steel for high-temperature high-pressure piping and vessels. For all Cr-Mo-to-carbon-steel joints. Lower carbon content improves resistance to cracking. Use where postweld heat treatment is not performed. Use to weld HSLA steels and nickel steels up to 3-1/2%. Gives high strength and good toughness down to -100°F (-73°C). High Mn and Si contents reduce porosity. For single and multipass welding of carbon and low-alloy steels. Use on S-bearing (free machining) steel. Farm implements, auto parts, light-gauge steel, AISI 4130, T-1. High-strength, tough weld metal for critical welds. HY80, HY100 and higher-strength steels, structural applications for service as low as -60°F (-51°C). ER80S-B2L 0.05 0.40– 0.40– 0.025 0.025 0.20 1.20– 0.40– – 0.35 0.70 0.70 1.50 0.65 ER90S-B3 0.07– 2.30– 0.90– 0.12 2.70 1.20 ER90S-B3L 0.05 2.30– 0.90– 2.70 1.20 Ni steel ER80S-Ni3 0.12 1.25 0.40– 0.25 0.25 3.00– – – – – 0.80 3.75 Mn-Mo ER80S-D2 0.07– 1.60– 0.50– 0.025 0.025 0.15 – 0.40– – 0.50 0.12 2.10 0.80 0.60 Otherd ER100S-1 0.08 1.25– 0.20– – – 1.40– 0.30 0.25– 0.05 0.25 1.80 0.50 2.10 0.55 ER100S-2 0.12 1.25– 0.20– 0.010 0.010 0.80– 0.30 0.20– 0.05 0.35– 1.80 0.60 1.25 0.55 0.65 ER110S-1 0.09 1.40– 0.20– 1.90– 0.50 0.25– 0.04 0.25 1.80 0.55 2.60 0.55 ER120S-1 0.10 1.40– 0.25– 2.00– 0.60 0.30– 0.03 0.25 1.80 0.60 2.80 0.65 ERXXS-Gc 1.20– 0.40– 1.50 0.65 a. As manufactured. b. Total other elements, 0.50. c. Minimum 0.50 nickel, 0.30 chromium, or 0.20 molybdenum. d. Ti, Zr, Al, 0.10 each, except –G wires. Figure 8-2. The letters HSLA identify the steels as high-strength, low-alloy materials.

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Copyright Goodheart-Willcox Co., Inc. Chapter 8 Manual Welding Techniques 131 Joint Preparation Joint edges prepared by thermal cutting processes have a heavy oxide fi lm on the surface, as shown in Figure 8-3. This oxide should be completely removed prior to welding in order to prevent porosity in the weld metal. Joint edges prepared by shearing should be sharp without tearing or ridges. Otherwise, dirt or oil can become trapped in the joint and result in faulty welds. Rough edges can be removed prior to welding with a light grinding. Weld Backing for Steel Groove welds that are welded from one side of the joint, where 100% penetration is required, can be backed with argon gas or a solid bar. Solid bars can be made of copper or stainless steel. These backing methods exclude air from the back- side or penetration side of the joint, which assists in wetting of the penetration. A wetted penetration has a smooth junction and even fl ow of the penetration onto the base metal. The exclusion of air also prevents the formation of scale and oxide. Preheating Steels Carbon steels less than 1″ (25.4 mm) thick and with less than .30% carbon generally do not require preheat. Welding on highly restrained joints is an exception. These joints should be preheated to 50°–100°F (10°–38°C) to minimize shrinkage cracks in the base metal and the weld deposit. A preheat temperature that is too low causes welds made on low-alloy steels, such as the chrome- moly steels, to have hard heat-affected zones. The hard heat-affected zones are caused by the rapid cooling rate of the base material and the formation of martensitic grain structures. A 200°–400°F (93°–204°C) preheat temperature slows down the cooling rate and prevents the formation of a martensitic structure. Martensite is a metallurgical term that defi nes a type of grain structure obtained by heating and quenching. The martensitic grain structure makes the metal hard. Parts that are welded are, in effect, heated and quenched. If the carbon content of the material is suffi cient, and the preheat temperature is too low, the material in the heat affected zone will harden during welding. This results in high tensile properties with very low ductility. The formation of hard martensite- type grains increases the possibility of cracking as the weld metal cools and shrinks. Tool steels have a very high carbon content and are prone to cracking in the heat-affected zone without suffi cient preheat. Figure 8-4 lists some recommended preheat temperature ranges for welding tool steels. Quenched and tempered steel requires preheat and interpass temperature control to retain the orig- inal mechanical properties of the metal. The manu- facturer’s recommendations for these temperatures should be strictly followed. Torch Angles and Bead Placement Proper manipulation of the welding torch is very important in making a good weld. The torch is usually held like a pencil, as shown in Figure 8-5. When welding is done in the fl at position, the hand should be placed lightly on a surface, so the hand can Figure 8-3. The oxide scale and small gouge indentations were formed on this piece of metal by the oxyacetylene cutting process. (Mark Prosser) Annealed Base Hardened Base Material Material Preheat Material Preheat Type and Postheat and Postheat Temperature Temperature W1, W2 250–450°F (121–232°C) 250–450°F (121–232°C) S1 300–500°F (149–260°C) 300–500°F (149–260°C) S5 300–500°F (149–260°C) 300–500°F (149–260°C) S7 300–500°F (149–260°C) 300–500°F (149–260°C) 01 300–400°F (149–204°C) 300–400°F (149–204°C) 06 300–400°F (149–204°C) 300–400°F (149–204°C) A2 300–500°F (149–260°C) 300–400°F (149–204°C) A4 300–500°F (149–260°C) 300–400°F (149–204°C) D2 700–900°F (371–482°C) 700–900°F (371–482°C) H11, H12, H13 900–1200°F (482–649°C) 700–1000°F (371–538°C) M1, M2, M10 950–1100°F (510–593°C) 950–1050°F (510–566°C) Figure 8-4. Thoroughly preheat the part to be welded to the required temperature. Do not allow the part to cool below the minimum temperature until postheat is complete.

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Copyright Goodheart-Willcox Co., Inc. Chapter 8 Manual Welding Techniques 129 Forgings Forging refers to pressing a shaped die into hot metal under high pressure. The metal is heated to a plastic state before it is forged so it will take on the shape of the die that is pressed into it. Forgings are made from billets, bars, round stock, or square stock. Forgings can be identifi ed by the remnants of the fl ashing that usually extends around the center of the part. Since the forging operation is done while the part is hot, a scale forms on the surface, similar to the scale on hot-rolled steel. Steel Classifications Steels are manufactured to specifi cations devel- oped by various organizations, including ASTM International. One grouping of steels under this classifi cation is ASTM A335. The assigned designa- tion identifi es the material as high-ferritic steel alloy pipe for high-temperature applications. Other steel specifi cations include SAE International’s Aerospace Material Specifi cations (AMS), the American Iron and Steel Institute (AISI) classifi cations, and corporation specifi cations. Filler Metals Filler metals used to join carbon steels, low-alloy steels, and tool steels must be selected to produce the desired mechanical properties of the weldment after any required welding or heat treatment. Carbon and low-alloy steel fi ller metals are selected from specifi - cations, such as AWS A5.18, AWS A5.28, MIL-E-23765, MIL-S-6758, and AMS6370. When selecting a steel fi ller metal, the welder should consider the basic type of steel to be welded and the possibility of excessive porosity within the completed weld. Figure 8-1 lists three classifi cations of fi ller metal, each with a 70,000 psi tensile strength that can be used to weld porosity-prone material. Figure 8-2 lists several types of fi ller metals that can be used to weld HSLA (high-strength, low-alloy) steels. Chromium-molybdenum steels (chrome-moly steels) are a class of extremely strong and hard steels. If the chrome-moly weldment is to be hardened after being welded, one of the following fi ller metals should be used: • 1-1/4% chrome—1/2% moly fi ller metal • 2-1/4% chrome—1% moly fi ller metal • 4%–6% chrome (AISI 502) If the chrome-moly steel weldment will not be hardened after welding, the following stainless steel fi ller metals can be used: • 25% Cr—20% Ni stainless steel fi ller metal • 25% Cr—12% Ni stainless steel fi ller metal Do not use stainless steel fi ller metals for welds in service over 1000°F (538°C). Welds subjected to temperatures above 1000°F (538°C) will have carbon migration from the steel to the stainless steel, which can cause weld failure. When selecting fi ller metals for tool steels, refer to the fi ller metal manufacturer for the recommended type. These fi ller metals have been specially devel- oped for specifi c applications and are not made to precisely conform to specifi cations issued by organi- zations such as ASTM or AISI. Filler Metal Quality Steel fi ller metals are supplied by the manufac- turer with a bright fi nish, oiled fi nish, or copper fl ash fi nish. Since these materials are susceptible to rusting, store them in a dry, heated area until they are needed. Always clean the fi ller metal with acetone or alcohol just before use. Return all unused material to the storage area. Solid Wires for Carbon Steela Per AWS A5.18 Classification Composition C Mn Si Ti Zr Al ER70S-2 0.07 0.90– 0.40– 0.05– 0.02– 0.05– 1.40 0.70 0.15 0.12 0.15 ER70S-3 0.06– 0.90– 0.45– – – – 0.15 1.40 0.70 ER70S-5 0.07– 0.90– 0.30– – – 0.50– 0.19 1.40 0.60 0.90 a P, 0.025 S, 0.035 Cu 0.50. Figure 8-1. The letters E and R in the classification code identify these filler metals as solid electrode wires that can be used in the GTAW process. The letter E indicates the wire is designed to carry current for the GMAW process. Some electrode wires can also be used (without current) as filler metal for the GTAW process. If the electrode wire can also be used for GTAW, the letter E is followed by the letter R (which stands for “rod”).

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