Showing papers on "Weldability published in 1976"

Aluminum alloys possessing improved resistance weldability

Abstract: Aluminum alloys exhibiting improved resistance weldability as well as excellent strength and formability characteristics are prepared which comprise 1.-5.% magnesium, 0.3-1.0% lithium, up to 1.0% manganese, up to 0.3% titanium, up to 0.20% vanadium, and balance essentially aluminum. The alloys of the present invention are particularly suited for automotive and like metal parts.

Effect of vanadium, nitrogen, and aluminium on the mechanical properties of reinforcing bar steels

Abstract: A systematic study has been made of the effects of vanadium, nitrogen, and aluminium on the properties of 18 and 30 mm rolled bars, having a base composition of 0·24%C–1·250%Mn–0·475%Si, as used for high-strength reinforcing bars. It has been shown that additions of vanadium up to 0·18% can increase the yield strength by 207–256 N/mm2, depending on the diameter and the level of other elements, without impairing the bend and rebend properties. The effect of vanadium on a 0·13C–1·5Mn–0·45Si steel has also been studied. Variations in finish-rolling temperature had very little effect on the properties. The weldability of a limited number of steels was shown to be equal to that of C–Mn steels. The properties of a number of commercial steel reinforcing bars having similar compositions are also included for comparison.

High-efficiency turbo-machine impellers

Abstract: A martensitic stainless steel to be used for the impellers of turbo-blowers, compressors and the like consisting essentially, based on weight of 0.04 - 0.15% C, up to 2.0% Si, 0.2 - 2.0% Mn, 3.5 - 6.0% Ni, 10 - 16% Cr, and at least one element selected from the group consisting of 0.5 - 3.0% Mo, 0.01 - 0.8% Nb, and the balance being Fe. The amounts of δ-ferrite therein is not more than 10%. The steel may further contain up to 0.2% additional element or elements, i.e., N, Al, Ti, Ca, and/or a rare-earth element or elements. The steel of this composition offers high strength, great toughness, and good weldability and, when annealed after welding, it will display the same properties as after quenching and tempering. Impellers made of this steel are for heavy-duty, high-efficiency applications.

Temper type high tensile steel superior in weldability

Abstract: PURPOSE: The development of temper type high tensile steel of 80 kg/mm class in tensile strength whose toughness and weldability are improved by the rise of hardenability with B, the increase of the toughness with teh decrease of N congent, and the decrease of Si content. COPYRIGHT: (C)1977,JPO&Japio

Laser beam welding using small dia beam - provides short welding times without altering props. near the weld

Abstract: In a process for the welding together of two or more materials, each possessing special physical properties, the materials are melted by a laser beam at the desired junction so that the molten zones are mixed together, but the materials outside the junction retain their original physical properties. For welding, one or more elements which are not present in the materials being welded, or only present in a minor amt., may be mixed in the molten zone. To restrict the radial spread of heat, the laser is pref. operated in the transverse TEM. mode, and the molten zone is pref. 0.1mm dia. using operational times of ca. 1 msec. Prevents the formation of zones adjacent to the weld which have different properties to those possessed by the materials being joined, e.g. transition zones. The materials being welded are pref. spring- or magneic-materials, plastics, dielectrics, ceramics, or a combination of SmCO5 with iron. The additional element(s) may improve weldability or weld-strength, or prevent cracking, and are pref. Nb, Ti or Ta when an Fe/Ni or a Cr/Fe/Ni alloy is being welded.

Continuous casting method for the production of rolled low carbon steel products with improved formability

Abstract: The relatively poor formability and spot weld fracture appearance of hot-rolled and heavy gauge cold-rolled low carbon steels (in which silicon is the primary deoxidant) have been attributed to manganese silicate stringer-type inclusions, generally found in this product. The addition of at least about 1/8 pound magnesium, per ton of steel cast, is shown to modify this deleterious inclusion morphology, with a resultant improvement in the ductility and weldability of such hot-rolled and the heavy gauge cold-rolled products.

Field weldability test for pipeline steels

Abstract: An investigation requested and supported by the American Petroleum Institute to develop a simple weldability test for pipeline steels that could be conducted in the field as a measure of their susceptibility to hydrogen-induced cracking is reported The goal was a quantitative and reproducible test that could be prepared and evaluated with a hammer, vise and power saws A 150 x 200 mm specimen cut from formed pipe with a central sawed slot in the girth direction and welded with a cellulosic electrode at welding conditions matching those used in the field was found to develop hydrogen-induced cracks Easy measurement of the extent of cracking was accomplished by tempering and heat tinting any cracks formed and then cutting slits into the weld from one side of the specimen and hammering off one side of the plate to expose any part of the fracture previously heat tinted The test was examined for sensitivity and reproducibility by testing a wide range of pipe steel compositions and thicknesses and was found to respond, as expected, to carbon, alloy content and gage The test was used to study the extent of cracking as a function of time lapse up to 20 min after weldingmore » Not only was there a strong effect of time lapse, but some of the more sensitive steels developed cracks in less than 5 min The effect of preheat on cracking was also clearly shown by the test Thus the test appeared potentially useful for determining the time limit between the root pass and hot pass and the necessary preheat It should have applicability to testing structural steels, generally, as well« less

Production of high tensile h-beam steel with excellent weldability for low t emperature service

Abstract: PURPOSE: To produce a high tensile H-beam with excellent weldability for low temp. service continuously rolling steel contg. austenite grain growth inhibiting elements such as Ti, Nb, V, Zr, etc. at a specified temp. to make austenite grain fine. COPYRIGHT: (C)1978,JPO&Japio

P-containing highly weldable corrosion resistant steel

Abstract: PURPOSE: To provide a P-contg. corrosion resistant steel of high weldability and corrosion resistnace suitable for use as a material for welded structures used in a corrosive atmosphere by making the C content of steel contg. P and Mo ultra low. COPYRIGHT: (C)1978,JPO&Japio

Selected mechanical properties of Inconel 718 and 706 weldments

Abstract: A preliminary study has confirmed the weldability of Inconel 718 and 706 and indicates that joint tensile strengths at room and elevated temperatures closely approach base metal values. Welding parameters were established for manual gas tungsten-arc welding (GTAW) of these alloys for butt, fillet, and plug welds. Weld quality and soundness were established through dye penetrant, radiographic, and metallographic inspections of material samples at various stages of the process. Relative ductility was shown through guided bend tests. Other mechanical properties of the weldments were determined as a function of temperature and heat treatment using transverse weld and T-joint tensile specimens. Ultimate strength and 0.2 percent offset yield strength of Inconel 718 weldments at room temperature, 1200, and 1400/sup 0/F was above 90 percent that of base metal and in most cases exceeded the minimum level specified by AMS 5596 and MIL-Hdbk-5B for base metal. Similar relative results were obtained with Inconel 706, although this alloy showed strength values 15 to 20 percent lower than Inconel 718. Both alloys were found to be fully weldable to each other. The strength of fillet welds was similar to base metal. Plug welds exhibited an average 30 percent reduction in strength (in the agedmore » condition) compared to base metal. Age hardening following welding was found to be acceptable without a need for a re-solution treatment.« less

Process for producing high tensile strength steel plate with excellent weldability and bendability

Abstract: PURPOSE:Production of high tensile strength steel plate with high strength and bendability after rolling without any further working, and having sufficiently high toughness at weld after heavy heat-input welding(more than 50KJ/cm).

Comparison of various chromium--molybdenum low-alloy steels for liquid- metal fast breeder reactor steam generators

Abstract: High-temperature strength, weldability, and decarburization behavior in liquid sodium of 2$sup 1$/$sub 4$ Cr--1 Mo steel with a wide variety of heat treatments and some carbon stabilized 2$sup 1$/$sub 4$ Cr--1 Mo steels are examined for the purpose of material selection of LMFBR steam generator tubes. Decarburization of 2$sup 1$/$sub 4$ Cr--Mo steel in sodium can be suppressed when it is appropriately normalized and tempered instead of annealed. The 2$sup 1$/ $sub 4$ Cr--1 Mo--Db--Ni steel is considered to be preferable to other stabilized steels, since a small addition of nickel assures sufficient strength, even if the normalizing temperature is as low as 950$sup 0$C. Stabilized steels should be welded carefully to obtain a fully penetrated bead. Preheating above 200$sup 0$C and postheating above 720$sup 0$C are required for stabilization. Compared with all the investigated properties, the materials recommended for LMFBR steam generator tubes are normalized-tempered 2$sup 1$/$sub 4$ Cr--1 Mo steel and, if decarburization is not allowable, 2$sup 1$/$sub 4$ Cr--1 Mo--Nb--Ni steel, with the condition that a sound-welded joint can be available. (auth)

Preparation of high tensile steel superior in toughness

Abstract: PURPOSE: To prepare the steel of high tensile strength and high toughness by quenching, annealing subsequent to hot rolling, by making the ratio of Ti/C to more tahn 4 and by improving the ductility and the weldability with decreasing the carbon content. COPYRIGHT: (C)1977,JPO&Japio

Rosenhain Centenary Conference - 2. Design implications for materials selection 2.5 Weldability and its implications for materials requirements

Abstract: The potential economic and technological advantages of welding over other joining techniques have made it the principal fabrication process for a wide range of engineering products. However, the achievement of good weldability makes demands on material quality which the material supplier must optimize with the required mechanical behaviour and an acceptable cost. The physical metallurgist has contributed significantly m providing a sound basis for materials selection based on an understanding of the potential welding problems and the factors responsible for them. The principal welding problems in steels, nickel alloys, aluminium alloys and titanium alloys are briefly outlined and the influence on material specifications discussed.

HIP Densification of Castings

Abstract: IIot isostatic pressing (HIP), a process involving the simultaneous application of heat and gas pressure, can be used to close internal porosity and improve the homogeneity of castings. Porosity and inhomogeneity can lead to lower yields and higher fabrication costs for parts made from castings and limit the application of castings because of lower strength and ductility than wrought materials. HIP densification of castings has demonstrated the closure of porosity, reduced rejections from radiography and surface penetrant inspection, and improved weldability, chemical milling ability and mechanical properties. Applications of the HIP process for castings have been achieved or are projected in four major areas: . Lower cost castings by reduced X-ray and surface penetrant rejection l Reduced component fabrication costs resulting from improved weldability . Wider application of large, complex castings achievable by increased casting parameter latitudes possible when followed by densification . Replacement of expensive wrought components with "premium" castings having increased fatigue strength and ductility. HIP densification has been demonstrated on castings of many alloy systems ranging from aluminum and titanium to the superalloys. Densification parameters of temperature, pressure and time required for porosity closure have usually been determined empirically, although some theoretical predictions based on high temperature creep strength have been made. Densification of artificial porosity (drilled holes) is a useful study technique. Surface bridging techniques have been developed to seal occasional surface connected porosity in order to provide the requisite impervious skin for closure of internal voids. Scanning Electron Microscopy (SEM) techniques have been used to validate the metallurgical bonding achieved in closed porosity.

Weldable* high tensile cast steel for centrifugal casting

Abstract: PURPOSE:To manufacture weldable, high tensile cast steel for centrifugal casting having tensile strength more than 80 Kg/mm , excellent weldability and high impact value of welded parts by hardenening and tempering.

Al-zn-mg cast alloy for welded structure

Abstract: PURPOSE: To provide the title cast alloy with excellent weldability, good mechanical properties and good resistance to stress corrosion cracking, which consists of Zn, Mg, Cu, Ti and B of each specified amt. and the balance Al. COPYRIGHT: (C)1978,JPO&Japio

Weldability and Toughness Specifications for Structural Steels in Japan - With Special Reference to WES-135 and -136

Abstract: During the last decade, the specifications, WES-135 and -136 played important guiding roles for developing and standardizing weldable high strength steels and structural steels for low temperature applications. In WES-135 which was established in September 1970, equivalent carbon content, C eq is adopted as an indication of the weld cracking susceptibility for high strength steels In order to accurately estimate the cracking susceptibility, a new parameter, P cm , is adopted as an indication of the carbon equivalent since March 1971. On the other hand, the toughness requirements specified in WES-136 are based on the correlation between small-scale tests and large-scale brittle crack propagation arrest tests as expressed in terms of K c -value. In this standard, steel plates are classi e into two classes of G and A, where G is generally accepted for welded structures where hazard of brittle fracture is anticipated and A is used for arresting a propagating crack. In order to establish revised toughness requirements for G class steels, comprehensive cooperative research works have been conducted since 1971. In this paper, the descriptions are focused on the weldability and toughness requirements of WES-135 and -136, their connexions with other standards, and the points under continuous examination.

Abrationnresistant 22layered pipe with good weldability

Abstract: PURPOSE:To obtain an abration-resistant, centrifugal casted 2-layered pipe with good weldability by using the same molten metal.

A method for improving weldability of niobium containing heat resistan t steel

Abstract: PURPOSE:A method for improving weld-crack susceptibility of niobium containing heat resistant steel.

Steel with excellent weldability for boiler

Abstract: PURPOSE: To obtain a steel pipe used for high temperature high pressure boilers from steel whose weldability has been improved by lowering C content. Insufficient strength of the steel due to low C content has been filled up with proper precipitation of carbides. COPYRIGHT: (C)1977,JPO&Japio

Heat resisting steel with excellent weldability and cold workability

Abstract: PURPOSE:The title heat resisting steel applied to the fields where high temperature stenght is not required such as exhaust gas converter of automobiles used in the range of temperature below heat resistant limit of stainless steel

Weldability of niobium containing high strength low alloy steel

Abstract: Significant production of niobium steels began about 15 years ago. The early steels contained up to 0.03% Nb and permitted higher yield strengths to be obtained in steels having greatly reduced carbon equivalents. Thus the heat- affected zone properties of these steels were excellent and they were widely adopted for welded construction of ships, bridges, pipelines and the like. More recent development has extended the use of niobium strengthening to higher yield strengths, more complex base plate composition, greater thicknesses and to more severe climatic regions such as the Arctic. In addition niobium contents have been increased (in some cases to above 0.10%) steel rolling and heat treating practices have become more sophisticated and welding evaluations are now concerned with all regions of the weld and adjacent base plate. The inclusion of weld metal toughness minimums in several recent specifications focused attention on the potentially detrimental effect of excessive niobium levels in high dilution welds. However recent studies have demonstrated that the behavior of niobium is strongly related to the carbon, titanium and vanadium contents of the base plate and to the characteristics of the welding process and consumables used. The paper summarizes the extensive current usage of niobium strengthened steel in a wide variety of welded constructions.

Welding 9% nickel steel: a review of the current practices

Abstract: The welding procedures used in shop and field fabrication of 9%Ni steel are presented. Empahsis is on large containers for transportation and storage of LNG. Background information on the development and metallurgy of this material is included. The mechanical properties and chemical compositions as listed in the specifications of various industrial countries are included. Consideration is given to the allowable design stresses which may be based on either tensile strength or yield strength. Also, the mechanical properties and chemical compositions of some of the welding products used to weld 9%Ni steel are discussed. The various welding processes that have been used in commercial production of large 9%Ni steel storage tanks are reviewed. The processes covered are manual shielded metal-arc, short-circuiting arc, and pulsed spray arc. The excellent weldability of this material is covered including the fact that preheat is neither required nor suggested. Also, in thickness of 50mm and under there is no need for a postweld stress relief.

Turbo type impeller with high performance

Abstract: PURPOSE:A steel material for high efficiency vane with combined properties of high strengh, high toughness, good weldability, and tempering after welding.

M551 metals melting experiment

Abstract: The Metals Melting Skylab Experiment consisted of selectively melting, in sequence, three rotating discs made of aluminum alloy, stainless steel, and tantalum alloy. For comparison, three other discs of the same three materials were similarly melted or welded on the ground. The power source of the melting was an electron beam unit. Results are presented which support the concept that the major difference between ground base and Skylab samples (i.e., large elongated grains in ground base samples versus nearly equiaxed and equal sized grains in Skylab samples) can be explained on the basis of constitutional supercooling, and not on the basis of surface phenomena. Microstructural observations on the weld samples and present explanations for some of these observations are examined. In particular, ripples and their implications to weld solidification were studied. Evidence of pronounced copper segregation in the Skylab A1 weld samples, and the tantalum samples studied, indicates a weld microhardness (and hence strength) that is uniformly higher than the ground base results, which is in agreement with previous predictions. Photographs are shown of the microstructure of the various alloys.