Showing papers on "Weldability published in 1986"

The welding metallurgy of HASTELLOY alloys C-4, C-22, and C-276

Abstract: The welding metallurgy (solidification and solid state transformations) of HASTELLOY* Alloys C-4, C-22, and C-276 has been determined. Varestraint hot-cracking tests performed on commercial alloys revealed a weldability ranking as follows: C-4 > C-22 > C-276. All alloys would be expected to have good weldability, with Alloy C-4 having a very low hot-cracking tendency, comparable to 304L stainless steel. Microstructures of gas-tungsten-arc welds of these alloys have been characterized by scanning electron microscopy and analytical electron microscopy. Intermetallic secondary solidification constituents have been found associated with weld metal hot cracks in Alloys C-276 and C-22. In Alloy C-276, this constituent is a combination ofP and ώ phases, and in Alloy C-22, this constituent is composed of σ,P, and ώ phases. With phase composition data obtained by AEM techniques and available ternary (Ni-Cr-Mo) phase diagrams, an equivalent chemistry model is proposed to account for the microstructures observed in each alloy's weld metal.

Cold rolled steel sheets having an improved press formability

Abstract: A cold rolled steel sheet or plated steel sheet having an improved press formability as well as excellent phosphatability, resistance to galling and spot weldability is produced by controlling a surface roughness pattern of the steel sheet so as to satisfy a center-line average surface roughness of 0.3-2.0 μm and a regularity parameter in at least one direction of not more than 0.25 defining the regularity of surface roughness.

Resistance to hydrogen cracking in steel weld metals

Abstract: In comparison to HAZ hydrogen cracking, there is little reported work on the influence of composition and microstructure on hydrogen cracking in weld metal. This paper describes the results of work using the G-BOP test to examine the effect of these factors at different heat inputs and hydrogen levels, mainly using SMAW, on the resistance to hydrogen cracking in low dilution weld deposits. For C-Mn, C-Mn-Mo, C-Mn-Ni and C-Mn-Ni-Mo deposits at around 10 ml H2/IOO g deposited weld metal, the resistance to cracking was primarily controlled by weld deposit hardness, with increasing hardness (over the range -v 200-330 HV) indicating a decreased resistance to cracking. At lower levels of hydrogen (<5 ml / 100 g), resistance to cracking was controlled much more by microstructure than by hardness. Microstructural types associated with good notch toughness (e.g., predominantly acicular ferrite) promoted good resistance, while predominantly ferrite with aligned M-A-C microstructures had poorer resistance to cracking.

Optimum controlling method of arc welding

Abstract: PURPOSE:To set automatically optimum welding conditions even if a work condition and an environment are varied by calculating a weldability index from welding current and welding voltage waveform data, and controlling an output of an welding power source or a wire feed quantity so that the exponential value becomes minimum. CONSTITUTION:As current I0 and voltage waveform data in case of CO2 or MAG welding, an index W for grasping quantitatively the weldability from a short-circuit time TS, an arc time Ta, an average value Is.ave of a current of the short circuit period, an average value Ia.ave of a current of the arc period, etc. is calculated, and by its value, an output of a welding power source or a wire feed quantity is controlled. In this regard, the weldability index W can be derived from an expression I which has used the short circuit time, the arc time, sigmaTS, sigmaTa, sigmaIs-ave and sigmaIa-ave being standard deviations of an average value of the current of the short circuit period and an average value of the current of the arc period, a constant K being the product of those values in a reference welding condition, an average value Ra.ave of a resistance in the arc period, an electric power Pa in the arc period, Ra.ave in optimum conditions, and a regression expression Ri and Pi.

Welding metallurgy and weldability of high strength aluminum alloys

Abstract: A literature survey was conducted to gather the information available on the welding metallurgy of high strength aluminum alloys, and its effect on their weldability. The report focuses on fusion welding of high strength aluminum alloys. Both conventional high strength aluminum alloys and newer products, e.g., PM aluminum alloys, Al-Li alloys and Al-matrix composites, are included. The survey covers a wide spectrum of publications, ranging from those using traditional equipment of study to those using more modern analytical instruments, such as electron microscopy and high speed computers. Recommendations of subjects for further research programs are presented. 84 references.

Effects of Ultrasonic Vibration on Diffusion Welding of Aluminum(Materials, Metallurgy & Weldability)

Abstract: The ultrasonic vibration has been applied in the diffusion welding of aluminum in an attempt to break up the superficial oxide film of the bond interface. The ultrasonic vibration and subsequent welding have been carried out in a vacuum of 10-2 Pa at 875 K to 893 K under a welding pressure of 1 to 3 MPa. The bond strength increased with the increase in the input power to the transducer and working time of ultrasonic vibration. The increase in pressure to the bond interface during the vibration, however, lowered the bond strength. TEM observation and electric resistance measurement of the bond interface revealed that the application of ultrasonic vibration had the effect of breaking up and dispersing the oxide film, which was closely related to the increase in bond strength. On the fractured surface of joint, dimple patterns, increased with the rise of bond strength. These portions may be regarded as places where the application of ultrasonic vibration promotes breaking up and dispersing the oxide film.

Effects of Coating Weight on the Resistance Spot Weldability of Galvanized Steel

Abstract: Etablissement de la relation entre la soudabilite de l'acier galvanise par immersion a chaud et l'epaisseur de la couche de zinc. Determination statistique de la fiabilite et de la reproduisibilite des essais realises

Novel cobalt-base superalloy and cast and welded industrial gas turbine components thereof and method

Abstract: Cobalt-base superalloys having special utility in the production of industrial gas turbine hot gas path components because of their unique combination of properties in specially heat-treated condition including excellent hot corrosion resistance, stress-rupture strength at high temperature, metallurgical stability, tensile ductility and weldability, consist essentially of 0.3 to 0.6% carbon, 27-35% chromium, 9-16% nickel, 6-9% tungsten, 0.45 to 2.0% tantalum, up to 3.0% hafnium, up to 0.7% zirconium, not more than 2.0% iron, 1.5% manganese and silicon and 0.05% boron, balance cobalt, the carbide formers being selected to satisfy the following equations: ##EQU1##

Austenitic stainless steel excellent in resistance to intergranular stress corrosion cracking and intergranular corrosion resistance

Abstract: PURPOSE: To obtain the titled stainless steel showing superior intergranular corrosion resistance and resistance to intergranular stress corrosion cracking even under a strongly oxidizing environment, by providing a composition which contains, besides Cr and Ni as essential components, prescribed amounts of Mo or/and Nb and in which amounts particularly of C, Si, Mn, P, S, and N are limited to prescribed values or below, respectively. CONSTITUTION: The titled austenitic stainless steel has a composition which contains, besides 13W16%, by weight, Cr and 6W26% Ni as essential components, 0.1W0.5% Mo or/and 0.01W0.1% Nb and in which amounts of C, Si, Mn, P, S, and N, in particular, are limited to ≤0.02%, ≤0.1%, ≤2%, ≤0.015%, ≤0.01%, and ≤0.2%, respectively. The stainless steel of this invention combines the above characteristics with superior workability and weldability. Accordingly, it is very useful as component material for various equipments to be exposed to a strongly oxidizing environment liable to cause intergranular corrosion and intergranular stress corrosion cracking. COPYRIGHT: (C)1987,JPO&Japio

Cryogenic Fe-Mn Austenitic Steels

Abstract: It is taken for granted that structural materials used for superconducting magnets of a fusion reactor must combine strength, toughness and fatigue resistance especially in case of welded structures at cryogenic temperatures Austenitic Fe-Mn alloys were expected to be promising candidates to meet the above requirements However, they proved to have some problems to be overcome in terms of cryogenic brittle fractures To optimize the mechanical properties, chromium, nickel, nitrogen and other elements were added to Fe-Mn alloy Consequently, 22Mn-13Cr-5Ni steel has been developed as the candidate steel Optimum manufacturing conditions have been established and the steel has been tested at cryogenic temperatures The results show that the steel maintains satisfactory strength of more than 12 GPa and fracture toughness of more than 200 MPa\(\sqrt m \) at 4 K

Bronze alloy for glass container molds

Abstract: This invention relates to a copper base alloy with improved toughness and weldability for use in making molds for glass containers. The alloy of the present invention contains copper, nickel and aluminum and may have intentional additions of iron for grain refinement and niobium for increased oxidation resistance. It is felt that niobium should be added when the alloy is to be welded under adverse conditions. The nickel content sould be between about 12 and 16 wt/o and the aluminum content between about 8.5 and 11.5 wt/o. If the aluminum content is above or below the range, and/or the nickel content is near or above 16 wt/o the alloy may have excessive hardness. Iron additions for grain refinement should be up to about 1.0 wt/o. The niobium, when added to improve weldability, should be maintained between about 0.5 and 1.0 wt/o.

Elevated temperature strength and toughness of ferritic steels.

Abstract: This paper describes the elevated temperature strength, toughness and alloy design of ferritic steels (dual-phase). For the development of ferritic steels which show excellent characteristics in creep rupture strength, toughness, weldability, resistance to oxidation and corrosion resistance to steam at the service temperature of 550-650°C, extensive studies have been carried out. The effects of Cr, Mo, V, Nb, C and Si on the creep rupture properties and Charpy impact properties of ferritic steels were investigated. The steel obtained from this work, 9Cr-1.5Mo-0.15V-0.05Nb steel, exhibits at least three times as much 105h creep rupture strength at 600°C as compared with 2% Cr-1 Mo steel and conventional 9Cr-IMo steel, and is superior to HT-9 by approximately 50%. This steel also shows higher resistance to embrittlement during service. Moreover, the effect of W on creep rupture properties was investigated, and TB12 steel containing W (12Cr-0.5Mo-1.8 W-0.2V-0.05Nb) was developed. This steel exhibits twice as much 105h creep rupture strength at 650°C as compared with modified 9Cr-1Mo steel and is superior to SUS 316 stainless steel. These new-steels would be useful for boiler tubes, steam generator tubes of fast breeder reactors and first wall of nuclear fusion reactors.

Thermo mechanical precipitation hardened high tensile steel superior in cold workability and weldability and manufacture thereof

Abstract: PURPOSE: To manufacture the titled steel stock, by specifying contents of Cu, Nb in steel stock having a specified compsn. CONSTITUTION: To Fe, by weight % 0.02W0.30 C, 0.05W1.0 Si, 0.5W2.5 Mn, 0.3W2.0 Ni, 0.005W0.20 Ti, 0.003W0.050 Nb, 0.5W1.5 Cu, 0.005W0.1 Al, ≤0.0070 N, ≤0.0030 O. The steel is heated to about 950W1,100°C, then rolled at about ≤850°C by ≥about 50% accumulative draft, then immediately water cooled to ≤about 250°C by ≥about 0.5m 2 /m 2 .min water quantity density. Cu improves strength without deteriorating HAZ toughness and raises strength due to ppt. hardening in normalizing process after pipe making, hence, ≥0.5% Cu is required, but toughness is lowered with the rise thereof. Since Nb steeply deteriorates HAZ toughness due to ppt. hardening, it is regulated to the min quantity required to recrystallization suppressing effect. The steel is easily cold bent at time of use, work hardened by bending while increasing strength and attaining to the aimed strength by successive tempering, further, superior in weldability. COPYRIGHT: (C)1987,JPO&Japio

Low c-cr-mo steel used under damp steam

Abstract: PURPOSE: To provide the titled economical steel excellent in EC resistance, weldability, strength and toughness by specifying a composition consisting of C, Si, Mn, Cr, Mo, Nb, V and Fe. CONSTITUTION: A low C-Cr-Mo steel has a composition consisting of, by weight, 0.02W0.14% C, 0.45W0.90% Si, 0.30W0.80% Mn, 0.70W1.60% Cr, 0.005W0.05% Nb and/or 0.005W0.08% V and the balance essentially Fe except inevitable impurities. This steel shows excellent EC resistance and weldability when used under damp steam and is capable of improving economical efficiency by lowering preheating temp. The steel showing the above properties can be obtained by refining a steel under component regulation into the above composition, subjecting it to rolling or forging by the ordinary method and then carrying out normalizing and successive tempering or annealing. COPYRIGHT: (C)1987,JPO&Japio

Corrosion resistant copper alloy having excellent weldability

Abstract: PURPOSE:To provide a corrosion-resistant Cu alloy having excellent mechanical strength and weldability by increasing the content of Fe, decreasing the content of Pb and compounding adequate Sn, Ni, P, Sb and Zn with the alloy. CONSTITUTION:The copper alloy is constituted of the compsn. consisting of 62-69wt% Cu, 0.5-1.5% Sn, 0.3-1.0% Ni, 0.02-0.1% P, 0.02-0.1% Sb, 0.02-1.0% Fe, <=0.1% Pb and the balance Zn and inevitable impurities. This alloy contains Cu at a relatively high ratio and therefore the alloy structure itself is in an alpha single phase region. The corrosion resistance of the copper alloy is thereby remarkably improved coupled with the synergistic effect of P and Sb for the improvement of the corrosion resistance in the presence of Sn and Ni. The weldability, mechanical property and hot workability are improved by the decreased ratio of Pb and the increased ratio of Fe and the reduction in the cost of production is made possible by the decreased compounding ratio of Ni.

Production of high-tension steel plate

Abstract: PURPOSE: To produce a steel plate having excellent weldability and high strength and toughness with high productivity by hot rolling a high-tension steel specified in the contents of C, Cu, Nb, etc., under controlled conditions and subjecting the steel to an aging treatment after cooling. CONSTITUTION: The steel consisting of 0.01W0.10wt% C, 0.01W0.80% Si, 0.20W2.0% Mn, 0.6W1.5% Cu, 0.05W0.060% Nb, 0.05W0.080% SolAl, and the balance Fe and unavoidable impurities is produced. Such steel is heated to 950W1250°C and is subjected to ≥50% rolling in a 900W1,000°C range. The finish rolling is ended at 800°C or over and ≤900°C. The rolled steel is cooled immediately thereafter down to ≤500°C at a cooling rate of 2W50°C/sec, then the steel plate is subjected to the aging treatment. Adequate rations of ≥1 kinds among Ni, Cr, Mo, V, Ti, and B are incorporated into the above- mentioned steel according to need. The high-tensile steel plate having excellent weldability and toughness is obtd. at the improved rolling efficiency by the above-mentioned method. COPYRIGHT: (C)1987,JPO&Japio

High-strength ferritic steel for boiler steel tube

Abstract: PURPOSE: To develop a steel stock for boiler steel tube excellent in strength at high temp., weldability, and toughness, by using, as a steel stock for boiler steel tube, a low-alloy steel having a specific composition to which Cr, W, V, and other elements are added. CONSTITUTION: As the steel stock for boiler steel tube withstanding the increase in size and elevated temp. and pressure of a thermal power generation boiler, the low-alloy steel having a composition which contains, by weight, 0.03W0.12% C, 0.1W1.5% Mn, 8.0W13.0% Cr, 1.8W3.0% W, 0.05W0.30% V, 0.02W0.10% Nb, 0.02W0.10% N, and 0.02W0.10% Mo or further contains 0.002W0.008% B and in which Si content is limited to 0.01W0.25% Si is used. In this way, the ferritic steel stock for boiler steel tube excellent in weldability and toughness as well as in strength under high-temp. and high-pressure conditions can be obtained. COPYRIGHT: (C)1988,JPO&Japio

High-strength heat-resisting ferritic steel pipe and tube

Abstract: A high-strength, heat-resisting ferritic steel pipe or tube for boiler use containing 0.03 to 0.15% C, 0.1 to 1.5% Mn, 8 to 13% Cr, more than 1.5% up to 3.0% W, 0.05 to 0.30% V, 0.02 to 0.12% Nb, 0.02 to 0.05% N, up to 1.0% Mo, and up to 0.25% Si. This pipe or tube has an improved high-temperature creep rupture strength and an excellent weldability and toughness.

Thin sn plated steel sheet for container having excellent corrosion resistance and weldability

Abstract: PURPOSE: To develop a surface treated steel sheet for can making having excellent seam weldability and the corrosion resistance under a coated film by forming the chromate treatment layer of the steel sheet which has fine ruggedness on the surface and has an Fe-Sn alloy plating layer, Sn plating layer and chromate treatment layer to the thickness inversely proportional to the thickness of the Sn plating layer in said part. CONSTITUTION: The rugged Sn plating layer 2 which has the fine ruggedness of 1W30μm spacings in projecting parts and has <0.07μm plating thickness of recesses, ≥0.20μm plating thickness of the projecting parts and ≤0.17μm average plating thickness is formed on the steel sheet 4 coated with Ni or Ni alloy contg. 1 or ≥2 kinds among Ni-Fe, Ni-P, Ni-Zn, Ni-Cu, and Ni-Cr alloys to form an Sn-Fe alloy layer 1 between the steel sheet and the plating layer by the inter-diffusion with the steel base. The chromate treatment film 3 is formed on such rugged Sn plating layer 2 in such a manner that the thickness thereof is inversely proportional to the thickness of the Sn plating layer 2. COPYRIGHT: (C)1987,JPO&Japio

Manufacture of high strength steel with superior weldability

Abstract: PURPOSE:To manufacture a high strength steel with superior weldability by subjecting an Nb-Mo-B-N steel to on-line hardening and tempering. CONSTITUTION:The composition of a steel is composed of, by weight, 0.04-0.11 % C, =1,000 deg.C, rolled at >=800 deg.C finishing temp., quenched at once to <=200 deg.C, and tempered at the Ac1 point or below.

Manufacture of nontempered thick steel plate having 50kgf/mm2 yield strength or more and superior weldability

Abstract: PURPOSE: To obtain the titled nontempered thick steel plate, by applying suitable heating, rolling an accelerated cooling to steel in which specified quantities of Nb, Ti, B, N are added, further C, Mn contents are specified. CONSTITUTION: Steel composed of, by wt% 0.02W0.06 C, 0.03W0.6 Si, 1.0W2.0 Mn, 0.005W0.03 Sol Al, 0.01W0.10 Nb, 2≤Ti/N≤5, 0.0003W0.003 B, 0.0035W0.0065 N, if necessary one kind or more among ≤1.0 Cu, ≤1.0 Ni, ≤1.0 Cr, ≤1.0 Mo, ≤0.1 V and the balance Fe is prepd. The steel is heated to 1,050W1,250°C, then rolled by ≥50% accumulated draft at unrecrystallized temp. range, the rolling is ended at Ar 3 WAr 3 +40°C, immediately cooled to ≤450°C at 2W30°C/sec rate. Thus, nontempered thick steel plate having superior weldability and ≥50kgf/mm 2 yield strength in nontempered state is obtd. COPYRIGHT: (C)1987,JPO&Japio

High-strength ferritic steel for boiler steel tube improved in weldability

Abstract: PURPOSE: To manufacture the titled steel for boiler steel tube capable of coping with the high temp. and high pressure of equipments as compared with conventional ferritic heat-resisting steels, by specifying respective contents of C, Mn, Cr, Mo, W, V, Nb, N, and Si and further by specifying the relationship between Mo and W contents. CONSTITUTION: The high-strength ferritic steel for boiler steel tube improved in weldability has a composition which contains, by weight, 0.03W0.12% C, 0.1W1.5% Mn, 8.0W13.0% Cr, <0.45% Mo, 1.0W2.1% W, 0.05W0.30% V, 0.02W0.12% Nb, and 0.005W0.10% N and in which Si content is limited to ≤0.25% and further relationship between Mo and W contents is within the area enclosed with a figure ABCDEF occupying the coordinate points in a tale. The steel of this invention has an increased strength at high temp. capable of coping with the high temp. and high pressure of equipments as compared with conventional ferritic heat-resisting steels and, moreover, this steel is also excellent in practical characteristics such as weldability, toughness, etc. COPYRIGHT: (C)1987,JPO&Japio

Tin-free steel strips useful in the manufacture of welded cans and process for making

Abstract: A tin-free steel strip comprising a steel strip, 40 to 150 mg/m 2 of a metallic chromium layer on the steel surface, and 5 to 25 mg/m 2 of a chromium compound containing layer thereon wherein the metallic chromium layer contains a plurality of protrusions, exhibits improved corrosion resistance and weldability and is thus useful in the manufacture of welded cans. Preferably, 1×10 11 to 1×10 14 protrusions having a diameter of 5 to 1000 nm at the base thereof are present per square meter of the metallic chromium layer surface. The tin-free steel strip is produced by chromium plating a steel strip in an aqueous solution containing CR 6+ preferably to a weight of 40 to 140 mg/m 2 , subjecting the chromium plated strip to anodic electrolysis, preferably at an eectricity quantity of 0.1 to 10 C/dm 2 , and subjecting the strip to a cathodic treatment in an aqueous solution containing Cr 6+ and a chromium plating aid so as to deposit additional metallic chromium, preferably in a weight of 10 to 60 mg/m 2 .

Method and apparatus for determining weldability of thin sheet metal

Abstract: A fixture is provided for testing thin sheet metal specimens to evaluate hot-cracking sensitivity for determining metal weldability on a heat-to-heat basis or through varying welding parameters. A test specimen is stressed in a first direction with a load selectively adjustable over a wide range and then a weldment is passed along over the specimen in a direction transverse to the direction of strain to evaluate the hot-cracking characteristics of the sheet metal which are indicative of the weldability of the metal. The fixture provides evaluations of hot-cracking sensitivity for determining metal weldability in a highly reproducible manner with minimum human error.