Showing papers on "Weldability published in 1991"
TL;DR: In this paper, the corrosion behavior of zinc-nickel alloy coatings of various thicknesses and different compositions in the chromated and non-chromated condition on steel was discussed.
Abstract: Improved corrosion resistance requirements, higher production costs and stringent pollution regulations have led researchers and commercial platers to study and develop new types of coatings for protection of steel components. Deposition of zinc-nickel alloy is of particular interest to the automobile industry where the coatings should satisfy many vital requirements such as formability, weldability, paint adhesion. This paper discusses the corrosion behaviour of zinc-nickel alloy coatings of various thicknesses and different compositions in the chromated and non-chromated condition on steel. The corrosion resistance was tested by various electrochemical methods and an industrially adopted salt spray test and the results indicate that an alloy deposit containing 15–18% nickel can efficiently replace zinc and cadmium deposits.
63 citations
TL;DR: In this paper, the wear behavior of the bainitic steels has been examined in relation to microstructure and the surface damage experienced by the worn rollers, and it is considered that such studies could lead to new insights into the wear process itself.
59 citations
Patent•
13 Mar 1991
TL;DR: A heat resistant ferritic stainless steel improved in low-temperature toughness, prevented from undergoing high-treme weld crack, and useful as a material of a passage of automobile exhaust gas, particularly a passage exposed to high temperature between an engine and a converter, which comprises up to 0.03 % of carbon, 0.6 to 2.1 % of nitrogen, and optionally a necessary amount of at least one of aluminum, titanium, vanadium, zirconium, tungsten, boron and REM, wherein the manganese to sulfur ratio is
Abstract: A heat-resistant ferritic stainless steel improved in low-temperature toughness, prevented from undergoing high-temperature weld crack, and useful as a material of a passage of automobile exhaust gas, particularly a passage exposed to high temperature between an engine and a converter, which comprises up to 0.03 % of carbon, 0.1 to 0.8 % of silicon, 0.6 to 2.0 % of manganese, up to 0,006 % of sulfur, up to 4 % of nickel, 17.0 to 25.0 % of chronium, 0.2 to 0.8 % of niobium, 1.0 to 4.5 % of molybdenum, 0.1 to 2.5 % of copper, up to 0.03 % of nitrogen, and optionally a necessary amount of at least one of aluminum, titanium, vanadium, zirconium, tungsten, boron and REM, wherein the manganese to sulfur ratio is 200 or above, [Nb]=Nb % - 8(C % + N %) » 0.2, and Ni % + Cu % « 4, the balance being iron and inevitable impurities in the production process.
41 citations
Book•
30 Jan 1991
TL;DR: A review of requirements and prescriptions of classification societies concerning annealing with partial recrystallization can be found in this paper, where the authors present a detailed discussion of the welding process.
Abstract: 1. Welding. 2. Thermal Cycle in Welding. 3. Strain Stress Welding Cycle. 4. Heat Affected Zone. Precipitation processes in the heat affected zone. Grain growth in the underbead zone. Behaviour of inclusions in heat affected zones. Properties of the heat affected zone. 5. The Weld Metal. The melting stage. Gas absorption in welds. Stage of weld metal solidification. Segregation and liquation. Stage of microstructural transformation. Properties of weld metals. 6. Weld Joint Cracking. Hot cracking. Cold cracking. Lamellar tearing. Stress relieve cracks. 7. Heat Treatment of Welded Joints. Review of requirements and prescriptions of classification societies concerning annealing. Temperature of stress relief heat treatment. Rate of heating and cooling. Mechanical modes of stress relaxation. Recrystallization heat treatment and annealing with partial recrystallization. 8. Selection of Steels for Welded Structures. 9. Weldable Structural Steels. 10. Weldability of Chromium, CrMo and CrMoV Steels. Metallurgy of base material. Heat treatment. Welding processes. Selection of filler material. Weldability. Post welding heat treatment. Microstructure and properties of weld metal. Operational properties of weld joints. Thermal embrittlement. 11. Steels for Cryogenic Temperatures. Metallurgical background. Austenite decomposition diagrammes for nickel steels. Heat treatment. Thermal embrittlement. Weldability. Selection of filler material. 12. Welding of High-Alloy Steels. Austenitic manganese steels. 13. Welding of Stainless Steels. Fundamental characteristics of weldability and the welding process. Stainless steels: Martensitic Ferritic Austenitic Duplex ferrite-austenite Martensitic austenitic Precipitation-hardened Practice in welding. 14. Cast Iron. Weldability of cast iron. 15. Nickel and its Alloys. 16. Copper Alloys. Weldability. Post welding heat treatment. 17. Weldability of Aluminium Alloys. Crackability tests. Choice of filler materials. Preparation for joining. Weldability. Welding. 18. Magnesium Alloys. Welding. 19. Cobalt. 20. Titanium, Tantalum, Zirconium, Hafnium and Niobium. 21. Welding of Beryllium, Uranium, Molybdenum, Vanadium, Gold, Silver and Lead. Summary. References. Index.
35 citations
TL;DR: In this paper, the history of precoated steel usage as car body materials in Japan is reviewed first, and the development of inorganic and organic dispersion coating, Zn-Mn plating, galvannealed steel by vapor deposition, and vapor phase deposited Zn−Mg coating are described.
Abstract: The history of precoated steel usage as car body materials in Japan is reviewed first. Japanese steelmakers developed galvannealed steel, duplex Zn–Fe coated steel, Zn–Ni coated steel and organic composite coated steel. All of them have been widely used. Recently, electrolytically Fe–Zn plated galvannealed steel and 1μm thick organic painted Zn–Ni electroplated steel have been applied. They have not only excellent corrosion resistance, but also good paintability, formability and weldability. Car body corrosion is classified into cosmetic corrosion and perforation. Newly clarified mechanisms for these two are explained. As for current research subjects, the development of inorganic and organic dispersion coating, Zn–Mn plating, galvannealed steel by vapor deposition, and vapor phase deposited Zn–Mg coating are described. Surface roughness control, application to vibration damping sheet, adhesive bonding, and the adaptation to lightweight cars are also important subjects to be studied now.
22 citations
TL;DR: In this article, laboratory and field data related to the resistance of alloy 625 to various aqueous media causing localized corrosion, stress corrosion cracking and other forms of attack is presented, as well as the versatility of the alloy for use in oxidizing, carburizing, chlorinated solvents and simulated waste incinerator type environments containing halide species.
Abstract: INCONEL@ alloy 625 is a nickel-chromium-molybdenum alloy that is used for its high strength, excellent fabricability and weldability, and outstanding corrosion resistance. The outstanding and versatile corrosion resistance of INCONEL alloy 625 under a wide range of temperatures and corrosive environments is the primary reason for its wide acceptance in chemical processing and other applications. This paper will present laboratory and field data related to the resistance of alloy 625 to various aqueous media causing localized corrosion, stress corrosion cracking and other forms of attack. Also the versatility of the alloy for use in oxidizing, carburizing, chlorinated solvents and simulated waste incinerator type environments containing halide species, will be demonstrated. @INCONEL is a trade mark of the Into family of companies. Superalloys 718,625 and Various Derivatives Edited by Edward A. Lmia The Minerals, Metals & Materials Society, 1991
19 citations
Patent•
13 Feb 1991
TL;DR: In this article, the authors proposed a thin hot-rolled steel sheet which is suitable for automobile parts, where Mn content is regulated to 10-30% to secure an austenite structure even at room temp.
Abstract: PURPOSE: To produce a thin hot rolled steel sheet excellent in strength and workability and suitable for automobile parts. CONSTITUTION: Mn content is regulated to 10-30% to secure an austenite structure stablt even at room temp. Hot rolling is done under hot rolling conditions for accelerating recrystallization (≥90% total reduction of area at roughing and finish rolling, ≥800°C finishing temp., and 1.1-5.0mm final sheet thickness) and cooling velocity is regulated to 10-100°C/s. Further, the contents of P and S as impurities are limited to ≤0.05%, respectively. By this method, the hot rolled high strength steel sheet in which austenite comprises ≥90% in an as-hot- rolled state and TS EL>3500 is satisfied and which has superior blankability and spreadability can be produced. This sheet also has excellent weldability and can suitably be used for automobile parts. COPYRIGHT: (C)1992,JPO&Japio
18 citations
Patent•
15 Oct 1991
TL;DR: In this article, a hot-rolled high tensile strength steel plate with high workability was proposed. But the workability of the resulting steel plate was not evaluated. And it was not shown that the resulting workability can be improved by cooling down to 300-450°C at (5 to 60)°C/s cooling rate and the to coiling.
Abstract: PURPOSE: To produce a high tensile strength hot rolled steel plate for working, combining superior strength, ductility, ring forgig characteristic, and weldability CONSTITUTION: This steel plate is a hot rolled high tensile strength steel plate with high workability, which has a composition consisting of 005-040%C, >005->08% Si, 08-25% Mn, 08-25% solAl, and the balance Fe with inevitable imprities and also has a structure composed essentially of polygonal ferrite and containing ≥5%, by volume ratio, of retained austenite and in which crystalline grain size is regulated to ≥12 ASTM grain size number A material steel with this chemical composition is reheated to a temp not lower than the Ac 3 point, held at this temp and hot-rolled, and the resulting steel plate is heated between the rolls of ≥ at least two stands in the latter stage of a finishing mill, finish-rolled while regulating the total draft in the temp region between (Ar 3 point -50°C) and (Ar 3 point +100°C) to ≥30%, and subjected to accelerated cooling down to 300-450°C at (5 to 60)°C/s cooling rate and the to coiling, by which the objective steel plate can be formed COPYRIGHT: (C)1994,JPO&Japio
15 citations
TL;DR: The basic qualifications of steel as a constructional material are discussed in this paper, and the current development of constructional steels for sheet, plate, bar and forging is described.
13 citations
TL;DR: In this paper, the development and use of modern materials for the power generation industry for the 1990s and beyond is discussed together with several important aspects of their weldability, and the need for additional base material research is highlighted along with the pressing need for the simultaneous evolution of filler metal.
12 citations
TL;DR: In this article, a metallurgical evaluation of the weldability of a high pressure/intermediate pressure turbine rotor has been undertaken to determine whether AS1M A470 (class 8) rotors can be weld repaired.
Abstract: A metallurgical evaluation of the weldability of a high pressure/intermediate pressure turbine rotor has been undertaken to determine whether AS1M A470 (class 8) rotors can be weld repaired. The work was carried out using a retired rotor that had been in service for over 20 years. The rotor base material was found to have experienced embrittlement during service. It was determined that no heat treatment was necessary before welding, as long as a post-weld heat treatment at 677°C was performed. The coarse grained bainitic structure and embrittled condition of the rotor material were metallurgical factors for possible reheat cracking of the heat affected zone (HAZ) in this type of rotor. However, the grain refinement experienced by the HAZ and the coarsening of carbides in the coarse grain HAZ improved the toughness greatly and eliminated or reduced the susceptibility of reheat cracking. The weldment produced shows good room temperature mechanical properties; however, the stress rupture properties o...
Patent•
05 Dec 1991
TL;DR: In this paper, the authors propose to improve the low temp. toughness of a stainless steel and to prevent the weld high temp. cracks by compositely adding Mo and Cu to a steel and specifying the Mn/S ratio, Nb content or the like therein.
Abstract: PURPOSE:To improve the low temp. toughness of a stainless steel and to prevent the weld high temp. cracks in a weld zone by compositely adding Mo and Cu to a steel and specifying the Mn/S ratio, Nb content or the like therein. CONSTITUTION:The compsn. of a ferritic heat-resistance stainless steel is formed of, by weight, =200, the content of Nb in accordance with a formula [Nb]=Nb%-8(C%+N%) is regulated to >=0.2 and the relationship of <=4 Ni%+Cu% is satisfied. If required, optimum amounts of one or more kinds among Al, Ti, V, Zr, W, B and rare earth elements are incorporated therein. This steel can be used for an exhaust gas purifying material in an internal combustion engine, a burning appliance or the like.
Journal Article•
TL;DR: In this article, the optimum welding parameters for producing maximum joint strength in dual-phase steel are established and the cause of weakening in the weldment is identified as tempering of martensite in the HAZ.
Abstract: Optimum welding parameters for producing maximum joint strength in dual-phase steel are established and the cause of weakening in the weldment is identified as tempering of martensite in the HAZ.
Patent•
28 Aug 1991
TL;DR: In this article, a method to obtain the composite vibration-dampening material excellent in weldability, vibration dampening property and spot weldability by a method in which when the intermediate layer composed of thermoplastic resin, crosslinking agent and conductive material are clamped between two metallic sheets and are stuck mutually under heating, the gel molecular fraction of the resin on the metallic sheet before being mutually stuck under heating is limited to at most specified value.
Abstract: PURPOSE:To obtain the composite vibration-dampening material excellent in weldability, vibration-dampening property and spot weldability by a method in which when the intermediate layer composed of thermoplastic resin, crosslinking agent and conductive material are clamped between two metallic sheets and are stuck mutually under heating, the gel molecular fraction of the resin on the metallic sheet before being mutually stuck under heating, is limited to at most specified value. CONSTITUTION:The resin composition composed of thermoplastic resin and crosslinking agent is prepared, and at least one surface to be laminated of a metallic sheet, and preferably both surfaces to be laminated thereof are directly coated with said resin composition and conductive filler, and then they are heated at room temperature or at the temperature of 100-200 deg.C and solvent is removed. Then, continuously or after said materials have been left as they are, they are laminated under heating, and thus composite vibration-dampening material is produced, The gel molecular fraction of the resin on the metallic sheet before being mutually stuck under heating is limited to at most 70%, and more preferably to at most 60%. If is exceeds 70%, the weldability is reduced. Thus, since conductive metallic powder, carbon and solvent, etc., may be easily added to the resin composition, the vibration-dampening material capable of spot welding is obtained.
Patent•
26 Jul 1991
TL;DR: In this paper, a heat resisting ferritic stainless steel which has superior strength at high temp and high temp. oxidation resistance and where toughness at low temp. is improved and further the occurrence of high temp welding crack in a weld zone to be the problem with respect to manufacturing and application is prevented.
Abstract: PURPOSE:To obtain a heat resisting ferritic stainless steel which has superior strength at high temp. and high temp. oxidation resistance and where toughness at low temp. as a defect of ferritic stainless steel is improved and further the occurrence of high temp. welding crack in a weld zone to be the problem with respect to manufacturing and application is prevented. CONSTITUTION:The steel is a heat resisting ferritic stainless steel which has a composition consisting by weight, =2 kinds among =200 and [Nb] represented by [Nb]=Nb%-8(C%+N%) is >=0.2 and in which superior heat resistance, toughness at low temp., and weldability are provided.
Patent•
28 Feb 1991
TL;DR: In this paper, a C-Si-Mn steel using relatively low carbon as a base is subjected to suitable hot rolling treatment and cooling treatment to form its structure into a mixed one of ferrite and bainite having fineness.
Abstract: PURPOSE: To stably manufacture a high strength hot rolled steel sheet having 50 to 60kgf/mm 2 TS and 75 to 85% yield ratio, having an extremely excellent strength-stretch-flanging balance and a good strength-ductility balance and furthermore excellent in weldability and fatigue resistant properties at a low cost CONSTITUTION: A C-Si-Mn steel using relatively low carbon as a base is subjected to suitable hot rolling treatment and cooling treatment to form its structure into a mixed one of ferrite and bainite having fineness (with ≤5μm average grain size) and is subjected to suitable skinpass rolling, by which the balance of strength and press formability (stretch-flanging properties in particular) excellent to such a degree that it has not been seen heretofor can be attained COPYRIGHT: (C)1992,JPO&Japio
Patent•
20 Feb 1991TL;DR: In this article, the zinc or zinc-alloy plated steel sheet having improved weldability and/or plating properties is produced by depositing on the steel sheet an iron-carbon plated layer having a carbon content of from 0.01% by weight to 10%.
Abstract: The zinc or zinc-alloy plated steel sheet having improved weldability comprises an extra low carbon steel sheet, an iron-carbon plated layer or a carbon-rich layer generated by diffusion of the iron-carbon plated layer on at least one major surface of the extra low carbon steel sheet, and a zinc or zinc-alloy plated layer on the iron-carbon plated layer or the carbon-rich layer. The zinc or zinc-alloy plated steel sheet having improved weldability and/or plating properties is produced by depositing on the steel sheet an iron-carbon plated layer having a carbon content of from 0.01% by weight to 10% by weight to a coating weight of from 0.01 g/m2 to 10 g/m2, optionally annealing the iron-carbon plated steel sheet, and depositing a zinc or zinc-alloy plated layer, preferably by galvanizing or galvannealing, on the annealed steel sheet.
TL;DR: In this article, the effect of welding by submerged arc welding on stress corrosion cracking (SCC) in NaOH is studied for carbon steels used as pressure vessels in the Bayer process industry.
Patent•
29 Nov 1991
TL;DR: In this paper, the authors developed the high-strength martensite stainless steel having excellent sea water resistance and weldability by hot rolling a stainless steel billet having a specific compsn., then hardening and tempering this stainless steel.
Abstract: PURPOSE: To develop the high-strength martensite stainless steel having excellent sea water resistance and weldability by hot rolling a stainless steel billet having a specific compsn., then hardening and tempering this stainless steel. CONSTITUTION: The stainless steel which contains, by weight%, <0.03% C, <1.0% Si, <2.0% Mn, 11 to 15% Cr, 2 to 7% Ni, over 2% to 4% Mo, <0.02% N or further one or two kinds of 0.01 to 0.5% Nb and 0.01 to 0.5% V or one or two kinds of 0.001 to 0.05% Al and 0.0005 to 0.005% Ca alone or in combination and consists of the balance Fe, and in which the Nieq. expressed by equation I and the Creq. expressed by equation II satisfy equations III, IV and a ferrite phase is not included in this compsn. is hot rolled and is hardened at ≤100°C from a temp. range from 900 to 1100°C; thereafter, the steel is subjected to a tempering treatment at 500 to 700°C. The martensite stainless steel having the excellent sea water resistance and the good weldability even with thick materials is obtd. COPYRIGHT: (C)1993,JPO&Japio
Patent•
18 Oct 1991
TL;DR: In this paper, the authors proposed a high tensile strength steel sheet combining sufficiently excellent strength, ductility, weldability and bore expandability and showing good workability, by which the hot rolled steel sheet having a structure essentially consisting of polygonal ferrite contg., by volume, ≥5% retained austenite can be obtd.
Abstract: PURPOSE: To provide a high tensile strength steel sheet combining sufficiently excellent strength, ductility, weldability and bore expandability and showing good workability. CONSTITUTION: Steel contg. 0.05 to 0.25% C, >0.05 to 1.0% Si, 0.8 to 2.5% Mn and 0.8 to 2.5% sol. Al or furthermore contg. specified amounts of one or more kinds among Ca, Zr, rare earth elements, Nb, Ti and V is held under heating to the Ac 3 point or above, is subjected to hot rolling, is completed with finish annealing at 780 to 840°C, is thereafter subjected to accelerated cooling and is coiled or is completed with finish rolling at 780 to 940°C, is subjected to accelerated cooling to the temp. range of 600 to 700°C at ≥10°C/s cooling rate, is subjected to air cooling in the above temp. range for 2 to 10sec, is furthermore subjected to accelerated cooling to 300 to 450°C at 220°C/sec cooling rate and is coiled, by which the hot rolled steel sheet having a structure essentially consisting of polygonal ferrite contg., by volume, ≥5% retained austenite can be obtd. COPYRIGHT: (C)1993,JPO&Japio
Journal Article•
01 Jan 1991
TL;DR: In this article, the authors describe the solidification behavior of weld pools, incorporating some recent advances in solidification theories, including ingot, single crystal, and rapid solidification processes.
Abstract: Solidification is a critical phase change occurring during welding that controls weld metal microstructure, properties, and ultimately weldability of alloys. In recent years, significant advances have been made in the solidification theories that relate to castings and rapidly solidified materials. A critical need exists to understand weld pool solidification in the light of these new theories. This paper will describe the solidification behavior of weld pools, incorporating some recent advances in solidification theories. Basic principles from ingot, single crystal, and rapid solidification processes will be used to understand and explain observed weld-metal microstructures. 62 refs., 12 figs.
Patent•
12 Mar 1991
TL;DR: In this paper, the end surface corrosion resistance of a laminated steel sheet having a resin layer in which a conductive powder is dispersed excellent without damaging the spot weldability of said laminate steel sheet by appling Zn-Cr alloy plating to at least the bonding surface of the resin layer of the steel sheets.
Abstract: PURPOSE: To make the end surface corrosion resistance of a laminated steel sheet having a resin layer in which a conductive powder is dispersed excellent without damaging the spot weldability of said laminated steel sheet by appling Zn-Cr alloy plating to at least the bonding surface of the resin layer of the steel sheets being the skin materials of the laminated steel sheet. CONSTITUTION: Zn-Cr alloy plating 1 with Cr-content of 1-70wt.% is applied to the surfaces coming in contact with a resin layer 3 in which a conductive powder is dispersed of steel plates 2, 2. By this method, the end surface corrosion resistance of the bonding surfaces of the steel plates 2 and the resin layer 3 is enhanced without damaging the spot weldability of the laminated steel sheet. COPYRIGHT: (C)1992,JPO&Japio
Patent•
03 Jul 1991
TL;DR: In this article, a steel sheet constituted of, by weight, 0.04 to O.C and is tempered at the optional temp. of the AC1 point or below.
Abstract: PURPOSE:To obtain a high strength steel showing good HAZ toughness even in high heat input welding applied in a building field or the like and having tensile strength of >=70kgf/mm class by simultaneously adding specified amounts of Cu and Ni to a steel having a specified compsn. and reducing the content of P and H. CONSTITUTION:A steel sheet constituted of, by weight, 0.04 to O.25% C, 0.05 to 0.60% Si, 0.3 to 2.0% Mn, 0.04 to 2.5% Cu, 0.5 to 5.0% Ni, >=1.5% Cu+Ni, 0.04 to 2.O% Cr, 0.04 to 1.0% Mo, 0.02 to 0.1% Al, 0.0003 to 0.0050% B, 0.002 to 0.012% N, <=0.010% P, <=1.0ppm H and the balance iron is subjected to hardening of executing water cooling from an austenite single phase area of <=1000 deg.C and is tempered at the optional temp. of the AC1 point or below. In this way, the objective steel in which the fractionization of the micro structure in the weld heat affected zone and the improvement of ductility are produced and improved in the toughness of the upper bainite in the weld heat affected zone can be obtd.
TL;DR: In this paper, the most complete and in-depth design, research and fabrication of Alloy 625 weld overlayed carbon steel pipe and fittings such as: 90 degree and 45 degree LR Elbows, Tees, Dished Heads, Reducers, Weld Neck Flanges, Valves, Spools, Manifolds, Nozzles, Blinds and so forth.
Abstract: This technical report presents the most complete and in-depth design, research and fabrication of Alloy 625 weld overlayed carbon steel pipe and fittings such as: 90 degree and 45 degree LR Elbows, Tees, Dished Heads, Reducers, Weld Neck Flanges, Valves, Spools, Manifolds, Nozzles, Blinds and so forth. Major developments for Offshore Projects took place in Calgary, Canada during 1989, 1990 and continued through 1991 such as: Development of an entire range of Alloy 625 weld overlay and butt welding procedures to cover majority of the welding processes: SAW, Pulsed GMAW, SMAW, GTAW, FCAW and base materials such as: Pl and 4130 with thicknesses from .250 in. (6.3mm) to no limit to be weld overlayed or butt welded. Development of a wide range of welding procedures to join dissimilar and similar materials such as: Pl to Pl, P43 to P43, Pl to P45, P43 to P45, 4130 to 4130, 4130 to P43 etc. All using the same filler metal: Alloy 625. Development of special welding consumables with special formulation to be used on Offshore Projects. Development of a unique welding technology and welding technique to provide a low iron content Alloy 625 weld deposit on carbon steel base mater ial. .Development of a specialized welding equipment to perform weld overlay on 45 degree and 90 degree LR Elbows with any exotic welding filler metal includinq Alloy 625, employi.nq a high productivity SAW System with near zero defect rate. ^. Corrosion tests performed on Alloy 625 weld overlay deposits and corrosion tests performed on self contained Alloy 625 weld overlayed Autoclaves. Complete study of Alloy 625 flux cored wire: weldability, corrosion testing and weld defect occurrence while weld deposits are performed using FCAW fillers available today. Superalloys 718,625 and Various Derivatives Edited by Edward A. Imia The Minerals, Metals & Materials Society, 1991
Patent•
01 Aug 1991
TL;DR: In this article, the electric resistance welded steel tube for machine structural use having excellent machinability is the one contg, by weight, 0.02 to 0.60% C, = 0.05 Ca/(1.25O+0.625S), if required, furthermore mixed with 0.10 to 1.50% Cr and the balance Fe with inevitable impurities, and can be obtd. by making a tube by electric resistance welding and thereafter executing heat treatment at >=500 deg.
Abstract: PURPOSE:To obtain the electric resistance welded steel tube for machine structural use having excellent machinability by specifying a compsn. constituted of C, Si, Mn, P, S, Al, N, O, Ca and Fe, making a tube by electric resistance welding and thereafter executing a specified heat treatment. CONSTITUTION:The electric resistance welded steel tube for machine structural use having excellent machinability is the one contg., by weight, 0.02 to 0.60% C, =0.05 Ca/(1.25O+0.625S), if required, furthermore mixed with 0.10 to 1.50% Cr and 0.10 to 0.60% Mo and the balance Fe with inevitable impurities, and can be obtd. by making a tube by electric resistance welding and thereafter executing heat treatment at >=500 deg.C. In the steel tube the amounts of S, Ca and O are specified to prevent the deterioration of its weldability and to improve its yield.
Patent•
29 Nov 1991
TL;DR: In this paper, the authors developed the high-strength martensite stainless steel having excellent weldability by hot rolling a stainless steel billet having a specific compsn., then hardening and tempering this stainless steel under specific temp. conditions.
Abstract: PURPOSE: To develop the high-strength martensite stainless steel having excellent weldability by hot rolling a stainless steel billet having a specific compsn., then hardening and tempering this stainless steel under specific temp. conditions. CONSTITUTION: The stainless steel which contains, by weight%, <0.03% C, <1.0% Si, <2.0% Mn, 13 to 17% Cr, 3.5 to 7.0% Ni, <0.02% N, 0.001 to 0.05% Al, 0.0005 to 0.005% Ca, or further, contains 0.1 to 2.0% Mo and 0.01 to 0.5% Nb alone or in combination and consists of the balance Fe, and in which the Nieq. expressed by equation I and the Creq. expressed by equation II satisfy equations III, IV and a delta ferrite phase is not included in this compsn. is hot rolled and is then hardened by rapid cooling down to ≤100°C from a temp. range from 900 to 1100°C; in succession, the steel is tempered at 500 to 900°C. The thick high-strength martensite stainless steel material usable for a large- sized welded structure is obtd. COPYRIGHT: (C)1993,JPO&Japio
Patent•
04 Apr 1991
TL;DR: In this paper, the roughness of the surface to be roughened of a steel plate is specified and the average roughness is made twice or more the thickness (d) of an org. resin film (Ra>=2d).
Abstract: PURPOSE:To obtain a painted steel plate generating no current supply inferiority even when no conductive substance is compounded and excellent in pressure contact weldability by specifying the roughness of the surface to be painted of a steel plate. CONSTITUTION:The surface to be painted of a steel plate is roughened and the average roughness Ra thereof is made twice or more the thickness (d) of an org. resin film (Ra>=2d) and the number of ridges per one inch of the roughened surface of the steel plate PPI is set to 80 or more (PPI>=80). As surface raughening processing, there is a shot or laser processing method but surface roughening processing using laser is desirable from the viewpoint of regularity and easiness. By this method, pressure contact weldability, especially. electric resistance weldability is made excellent and a painted steel plate can be obtained without compounding a conductive substance.
TL;DR: In this article, a nitrogen-added Ni-based filler metal, 22Cr-60Ni-9Mo-0.1N, was developed for the welding of a 6%Mo superaustenitic stainless steel.
Abstract: Corrosion resistant alloy welds for seawater applications are necessary to be over-alloyed with Cr, Mo and nitrogen to have an increased Pitting Index value. The desired weld chemistry also requires less microsegregation of Cr and Mo and precipitation free microstruciure not only for higher corrosion resistance but also for good mechanical properties and weld hot-cracking resistance. Based on such requisites for the welds, nitrogen-added Ni-based filler metal, 22Cr-60Ni-9Mo-0.1N, was developed for the welding of a 6%Mo superaustenitic stainless steel.The weldment by the newly developed filler metal showed excellent chloride corrosion resistance comparable to the base metal. The weld solidification and microstructure were fully austenitic without any other phases and brittle precipitates in the whole weld. Thereby, the weldment also offered good ductility, toughness and hot-cracking resistance superior to the weldment by the conventional Alloy 625 filler metal.