Showing papers on "Weldability published in 1979"

Welded Joint Design

Abstract: Arc welding processes Steels and their weldability Distortion and residual stresses Terms and definitions Weld preparations Weld symbols on drawings Static strength of welded joints Fatigue life Brittle fracture Weld procedures Quality management Inspection and non-destructive testing.

Process for producing high-tension bainitic steel having high-toughness and excellent weldability

Abstract: A process for producing high-tension bainitic steel having high-toughness and excellent weldability by subjecting a bainitic steel of a specific composition to a low-temperature heating and subsequently rolling the steel under specific conditions.

Nickel-base hard facing alloy

Abstract: A hard surfacing alloy composition formed from an alloy containing correlated percentages of chromium, molybdenum, tungsten, manganese, columbium, titanium, carbon, silicon and iron, the balance being nickel. The alloy exhibits a good combination of hot hardness at elevated temperature and weldability.

P-containing corrosion resistant steel with high weldability

Abstract: PURPOSE: To obtain the titled corrosion resistant steel being excellent as a welded structure material under corrosive environment by sea water and atmosphere by extremely reducing a content of C, N of a P, N containing steel or by adding Mo, Cu, Ni or the like in a specified amount, as well as adding Nb, V, Ti or the like in a specified amount. CONSTITUTION: A P-containing corrosion resistant steel with high weldability is obtained from a material consisting of, C; 0.07 or less, Si; 1 or less, Mn; 2.5 or less, P; 0.03W0.2, Al; 0.003W0.2, N; 0.003 or less and a balance of Fe, each in wt% basis. Because, C and N content is extremely lowered, weld cold cracking and joint brittleness are not generated. Moreover, one or more of Mo, Cu, Ni, Co, Cr, W may be added in a total amount of 4% or more, or 0.2% or less of one or more of Nb, V, Ti, Zr, Ta, B, rare earth elements, Ca, Mg, Te, Se may be added moreover. The above described two additives may be optionally added together. COPYRIGHT: (C)1981,JPO&Japio

Production of high toughness bainite high tension steel plate having excellent weldability

Abstract: PURPOSE: To produce steel plate for line pipe in cold regions having excellent strength, toughness and weldability by a method wherein steel having specified compositions is heated at a low temperature and rolled under specified rolling condition to form steel having bainite structure, and the said steel having the above properties after the above rolling treatment or after tempering treatment. CONSTITUTION: Steel materials contain C 0.003W0.035%, Si<0.4%, Mn 1.4W 2.0%, S<0.006%, Al 0.05W0.08%, Nb 0.01W0.08%, Ti 0.005W0.025%, B 0.0008W0.0018% and N 0.001W0.005%, and have a composition within the range 0≤Ti%-3.4×N%≤0.01. Further, the steel materials may contain REM 0.001W 0.03% and/or Ca 0.0005W0.005% and/or a specified amount of one or more of V, Cr, Mo and Ni, and have a composition within the range 1≤REM/S≤10 and Mn+Cr+2Mo≤2.5. The steel materials are heated to below 1150°C. By subsequent rolling, cumulative rolling reduction at a temperature below 900°C is above 60%, and finishing temperarure is from 550 to below 700°C. COPYRIGHT: (C)1980,JPO&Japio

Construction steel exhibiting high fatigue strength

Abstract: Construction steel exhibiting a high fatigue strength. The invention relates to construction steels. These steels are essentially characterized by the fact that they comprise, besides iron, at a maximum 1.6% (by weight) of C, 0.3 to 3% (by weight) of Mn and/or Ni, at a maximum 1.8% (by weight) of Si, 0.6 to 4% (by weight) of Cu, at a maximum 3% (by weight) of Mo and/ or Co, 0.02 to 0.4% (by weight) of Nb and/or V, at a maximum 0.006% (by weight) of B, at a maximum 0.4% (by weight) of Z and/or Be, 0.2% (by weight) of Al, 0.005 to 0.2% (by weight) of N, at a minimum 0.0005% (by weight) of Ca, and at a maximum 0.25% (by weight) of Ce and/or Pb, and up to 0.1% sulfur. These steels exhibit a high fatigue strength and, up to a well defined carbon content (0.3%), a good weldability and are resistant to corrosion in the air.

Steel products for oil well pipe having superior sulfide stress corrosion crack resistance and tensile strength of 60kg/mm2 or more

Abstract: PURPOSE: To enhance the sulfide stress corrosion crack resistance of steel products without exerting unfavorable influence on the mechanical properties and weldability by providing a specified compsn. contg. C, Si, Mn, P, S Al and Ca to the steel products. CONSTITUTION: The compsn. of steel products is composed of, by wt., C 0.2W 0.5%, Si 0.10W0.35%, Mn 0.5W1.90%, P≤0.015%, S≤0.010%, Al 0.01W0.10%, Ca 0.0010W0.020%, and the balance Fe and inevitable impurities. It may further contain one or more out of Cr 0.1W2.0%, Mo≤0.50%, Nb 0.05%, V≤0.10%, Ti 0.01W0.10%, B 0.0005W0.005%, Cu 0.20W0.60% and Ni 0.10W0.60%. The products have superior sulfide stress corrosion crack resistance and a tensile strength of 60kg/mm 2 or more, and they are suitable for use as steel products for oil well pipes. COPYRIGHT: (C)1980,JPO&Japio

Martensitic stainless steel having excellent weldability and workability for structural use

Abstract: Martensitic stainless steel having excellent weldability and workability for structural use is obtained by limiting each content of carbon and nitrogen to the low value less than 0.02% and the content of nickel to less than 0.1% and by satisfying the following requirement. Cr equivalent=[%Cr]+0.4×[%Si]-0.4×[%Mn]-0.7×[%Ni]-0.6.times.[%Cu]-35×[%C]-10×[%N]≦10.5, wherein % means weight % of the element in steel.

Production of weldable low alloy heat treated hard top rail

Abstract: PURPOSE:To produce the rail which is easy to weld and forms the zeld zone in which the material characteristics, such as strength and structure of the weld zone, have not much difference from those of base metals, by making the cooling conditions equivalent to the rate of cooling at the rail welding at the time of heat-treating the top part of the rail made of high carbon low alloy steel. CONSTITUTION:The rail is produced by the high carbon low alloy steel which contains C; 0.55-0.85%, Si; 0.50-1.20%, Mn; 0.80-1.50%, Al; 0.005-0.05% or further contains Cr; 0.20-0.90%, Nb; 0.004-0.010% and contains these so that the total amount of Cr+Mn becomes 1.60% or less. The top surface layer of this rail is heated to 850 deg.C or more to austenitize its structure, after which it is quenched at 50-400 seconds between 800 deg.C and 550 deg.C. The structure becomes fine pearlite from the rail top surface layer down to a depth of 10mm and the rail of the superior weldability whose tensile strength at ordinary temperature is 120kg/mm or more and surface hardness HB330 or more may be produced.

Spot Weldability of High Strength, Cold Rolled Steels

Abstract: Four high-strength, low alloy (HSLA) steels with a 275 MPa minimum yield strength, were evaluated for spot weldability. The effects of variations in electrode diameter, electrode force, hold time, weld time, and weld coupon dimensions on strength, impact toughness, and nugget characteristics were examined by independently varying single welding parameters. Within the ranges studied, electrode diameter and force, and hold time were found to have minimal effects. Steel composition has a significant effect on both tensile-shear and cross-tension strength. Differences in base steel resistivity caused by compositional changes may cause changes in the current level required to achieve a specified nugget diameter. Usable current range was found to be a function of weld time and electrode force. An examination of spot welds made with automotive weld schedules showed that only schedule C (Chrysler), with significantly higher levels of welding current and electrode diameter, produced increased weld strengths. Neither nugget fracture appearance or minimum tensile-shear strength values alone were reliable indicators of overall weld quality. It was concluded that to facilitate the utilization of high strength, cold rolled steels and still ensure spot weld integrity, different criteria should be emphasized, including the attainment of an average nugget diameter of sufficient size to produce values of tensile-shear and cross-tension strength specified relative to values established for plain carbon steels.

Steel products with nitrate stress corrosion cracking resistance

Abstract: PURPOSE:To enhance the nitrate stress corrosion cracking resistance of steel products by adding Cr>=2% to a steel together with Nb and restricting the total content of N to C and C+N =2% forms a passive state film. By restricting the total content of C and N to C+N<=0.12% and adding Nb, the film is stabilized and the weldability and gas cutting property of the steel are improved. Since the passive state film improves the nitrate stress corrosion cracking resistance of the steel, the steel is suitabe for use as a shell for a hot stove, a boiler, etc. generating NOx.

Small diameter flux-cored welding wire excelling in feeding performance

Abstract: PURPOSE:To improve the wire feeding performance and enhance the weldability, by maintaining the outer skin hardness within a limited range, in a small diameter flux-cored welding wire. CONSTITUTION:In a small diametr flux-cored welding wire measuring 1.2-1.6mm.phi in diameter, the wire is manufactured through an annealing process in a wire drawing process using roller dies so that the Vickers hardness of the outer skin of the wire may be 160-240Hv. This wire, as compared with the conventional small diameter flux-cored welding wire, excels in the wire feeding performance, so that defects in welding due to poor wire feeding performance may be eliminated. Besides, the arc length is constant and bead width is uniform, and is less spatter, so that excellent weldability may be achieved.

On the Various Properties of Ni-Cr-Mo-W Heat Resistant Alloys for Nuclear Steel-making System

Abstract: Synopsis: Ni-Cr-Mo-W system alloys were investigated in order to develop a heat resistant alloy which may satisfy various properties required for heat exchanger tube materials of nuclear steel-making system. In the first step, we investigated the effect of alloy elements on formability, high temperature strength, aging characteristics and weldability. And we selected some candidate alloy compositions in terms of creep rupture strength at 1000°C. Out of these alloys, Ni-0.07C-25Cr-5Mo-5W alloy turned out to be superior to other alloys when taking various properties. In the second step, the effects of C and Cr contents on creep rupture strength at 1000°C were examined on this alloy. The creep rupture strength was found to irlcrease when C content was reduced from 0.07% to 0.03% and Cr content was raised from 25% to 27.5% and solution treatment temperature was raised. In terms of various properties, Ni-0.03C-27.5Cr-5Mo-5W system alloy was chosen, which also proved resistant to helium environment. In conclusion, we developed a candidate alloy with compositions of Ni-0.03C-27.5Cr-5Mo-5W which seemed to have high possibility of satisfying the creep rupture strength target, that is more than 1kg/ mmmm2 at 1000°C and 5×104 hours in helium.

Preparation of zn based alloy coated steel plate

Abstract: PURPOSE:To obtain an alloy coated steel plate with excellent corrosion resistance and weldability by a method wherein an Ni or a Co coating layer is formed on a steel plate and, subsequently, a Zn coating layer is formed and subjected to heat treatment under a specific temp. CONSTITUTION:An Ni or a Co coating layer is formed on a steel plate by a vapor depositing method, a plating method or the like and, thereafter, a Zn coating layer is formed to adjust a total coating amount of 5-100g/m and an Ni or a Co ratio to 5-50%. The obtained double coating steel plate is heated to a temp, which is above m.p. of Zn to form a Zn-Ni-Fe, Zn-Co-Fe or Zn-Ni-Co-Fe coating layer and corrosion resistance and weldability is enhanced as well as peeling resistance of a paint after painting is excellent.

Alloy steel with superior strength and toughness and its manufacture

Abstract: PURPOSE: To enhance the strength and toughness of an Ni-contg. alloy steel by lowering the contents of C, Si, Mn, etc. of the steel, adding Mo, Ti, etc., and carrying out specified heat treatment to form martensite single-phase structure. CONSTITUTION: An alloy steel contg. 0.05W0.3% C, <0.1% Si, <0.1% Mn, 6.0W 12.0% Ni, 0.5W5.0% Mo, 0.1W2.0% Ti and 0.1W2.0% Al or further contg. 1.0W 8.0% Co is subjected to solubilizing treatment at ≥800°C to dissolve the Mo, Ti or Co in the matrix metal. The treated steel is cooled at ≥5°C/min cooling rate to form martensite single-phase structure, and then it is tempered at 100W700°C to provide high strength, toughness and weldability comparable to those of maraging steel. The lowered contents of C, Mn, Si, etc. result in enhanced toughness, and insufficient strength due to the lowered C content is compensated for by the precipitation of alloying elements such as Mo and Ti. COPYRIGHT: (C)1981,JPO&Japio

Improved Ferritic–Austenitic Stainless Steel

Abstract: For the efficient operation of chemical process plant it is of paramount importance to ensure as far as possible that the periods of closurefor maintenance and repair are minimised.The arduous conditions encountered in many chemical plants as a result of progressive trends towards. higher yields, etc., have therefore highlighted the need for greater strength and pitting resistance than can be obtained in conventional austenitic stainless steels. This paper describes the development of ferritic/austenitic high chromium duplex cast stainless steels and demonstrates how, by addition of nitrogen and close control of composition, certain inherent drawbacks of duplex alloys can be overcome. The nitro gen-containing steel has an attractive combination of mechanical properties, corrosion resistance, ductility, weldability and castability, and has received application in a wide range of aggressive environments.

Surface treated steel plate with excellent spot weldability

Abstract: PURPOSE: To enhance spot weldability by coating a zinc (alloy) plated layer formed on a steel plate by a metal oxide film. CONSTITUTION: To a surface of a corrosion resistant steel plate plated by zinc or zinc alloy such as Zn-Ni alloy, a suspension containing metal oxide such as Al 2 O 3 , SiO 2 , TiO 2 or the like is contacted to adhere these oxide film up to 0.5g/m 2 max. Because electric resistance of the obtained steel plate is high during contact time, electric current concentration and heat generating amount are increased and spot weldability is improved. COPYRIGHT: (C)1980,JPO&Japio

High-strength high-electrically-conductive copper alloy with superior weldability

Abstract: PURPOSE: To enhance the weldability of a high-strength high-electrically-conductive copper alloy used as a material for the damper shield, etc. of a large capacity superconductive generator by adding a specified amt. of Ni and Si to copper. CONSTITUTION: An alloy consisting of Ni 1.3W2.5wt%, Si 0.3W0.6wt%, and the balance Cu and inevitable impurities. The Ni and Si contents of the alloy is appropriately adjusted to a ratio in which a Ni 5 , Si 2 intermetallic cpd. is formed. The Ni and Si are mostly being dissolved in the copper before welding, and the Ni-Si intermetallic cpd. precipitates in an about equilibrium state at a desired temp. after welding. Accordingly, occurrence of weld cracks is prevented, and satisfactory welding results are obtd. by putting a Ni alloy on a groove even in welding to an iron alloy. By making use of this alloy no weld crack occurs in a damper shield, etc., and superior strength and electrical conductivity are provided. COPYRIGHT: (C)1980,JPO&Japio

Production of high strength cold-rolled steel plate of good coatability, weldability and workability

Abstract: PURPOSE: To produce a high strength cold-rolled steel plate of superior weldability, coatability and workability, by making the addition amount of strength imparting elements as small as possible and applying the specific heat treatment at the continuous annealing, at the time of producing a steel plate for automobiles. CONSTITUTION: A steel slab contg. 0.05W0.12% C, ≤1.2% Si, 0.7W1.5% Mn, 0.04W0.15% P, and 0.01W0.10% sol. Al is hot-rolled, and cold-rolled to produce a steel plate. In continuous annealing of the steel plate, first it is soaked for 20secW 2min at 730W850°C, after which it is quickly cooled by gas-water cooling at 30W 300°C/sec cooling rates. Or it is quickly cooled down to 500W300°C temperature range by said method, after which it is subjected to over aging treatment at 300W 500°C. The amounts of C, Mn, Si, P, Cr which are strength imparting elements are decreased as far as possible to prevent the degradation in weldability and coatability. The strength may be improved by the heat treatment under specific conditions. COPYRIGHT: (C)1981,JPO&Japio

Manufacture of high strength steel pipe having good weldability for use at ordinary and medium temperature zone

Abstract: PURPOSE:To manufacture the steel pipe having high strength at ordinary and medium temperatues and good weldability by a method in which the steel pipe containing given proportions of C, Si, Mn, Mo, V, and Al is heated at a temperature higher than the point Ac3, hardened, and then tempered at a temperature lower than the point Ac1. CONSTITUTION:The steel pipe, consisting of 0.03-0.15wt% C, 0.01-0.80wt% Si, 0.50-2.00wt% Mn, 0.01-0.30wt% Mo, 0.005-0.10wt% V, 0.001-0.10wt% Al, and the balance Fe, is heat-treated in the following; that is, the steel pipe is heated at a temperature higher than the point Ac3, hardened to form an uniform austenite structure, and then tempered at a temperature higher than 600 deg.C but below the point Ac1. Thus, the steel pipe, although its C content is reduced, can keep a sufficiently high strength in a temperature range from ordinary temperature to 450 deg.C and also its coupling portion can keep a sufficiently high strength in the said temperature range even when undergone reheating at the welding time.

Heat treating method of high tensile steel for low temperature

Abstract: PURPOSE: To improve toughness, weldability and strength at low temperature by applying two stages of heating and cooling pre-treatments at the specific temperature prior to hardening and annealing of the V-containing Ni-Cr-Mo cast steel. CONSTITUTION: Two stages of pretreatments of heating the V-containing Ni-Cr-Mo cast steel containing C; 0.10W0.20%, Si; 0.20W0.80%, Mn; 0.60W1.0%, P< 0.03%, S<0.03%, Ni; 0.6W2.0%, Cr; 0.4W1.0%, Mo; 0.15W0.60, V; 0.05W 0.20% to a temperature of 1,100°C or more and cooling the same then reheating the same at 900W950°C followed by cooling is applied thereto prior to its hardening and annealing. Even if the cooling at the hardening is made gentle, the toughness at low temperatures is improved by the prevention of the grain boundary deposition of ferrite and the parting of the carbide depositing at the grain boundaries. COPYRIGHT: (C)1980,JPO&Japio

Cast stainless steel for extremely low temperature use

Abstract: PURPOSE:In 18Cr-8Ni-Mo base austenite stainless steel, alloy components are adjusted so that ferrite phase is formed to cause two-phase structure, thereby enhancing toughness and weldability at extremely low temperature CONSTITUTION:An austenitic stainless steel contains, C<008%, Si<20%, Mn< 30%, Ni: 6 to 15%, Cr: 18 to 24%, Mn: 05 to 35% In this composition, the content of ferrite-producing element Cr and Si relative to austenite-stabilizing element Ni is adjusted so that 3 to 30% of ferrite phase will form in austenite structure Such structure drastically improves crack sensibility at welding, prevents embrittlement by inhibiting the precipitation of Cr carbide at heat affected zone of welding area This further inhibits martensite modification at an extremely low temperature

Spot weldability of dual-phase steel

Abstract: The spot welding characteristics of VAN-QN (80), a dual-phase HSLA (high strength, low alloy) steel, were examined with regard to the strength and ductility of spot welds under static, impact and cyclic loading and compared to a conventional V-N HSLA steel and SAE (Society of Automotive Engineers) 1008 low carbon steel. The maximum tensile shear strength of VAN-QN (80) spot welds was found to be proportional to the thickness and ultimate tensile strength of the base metal. VAN-QN (80) spot welds, therefore, were only slightly lower in strength than those in a conventional 80 ksi yield strength HSLA steel but up to twice the strength of welds in low carbon steel. Weld ductility was lower for VAN-QN (80) than for low carbon steel but greater than for conventional HSLA steel and increased with material thickness. The impact and fatigue properties of VAN-QN (80) welds were similar to those in conventional HSLA and low carbon steels. Weldability, as determined by the range of current over which acceptable welds could be produced, decreased with increasing thickness and was the same for VAN-QN (80) as for low carbon steel. The excellent weldability of VAN-QN (80) steel is attributed to a combination of the following properties: moderate hardenability, insensitivity of the dual-phase microstructure to softening by the heat inputs typical of spot welding, and a low yield strength to ultimate tensile strength ratio.

Low hydrogen type covered electrode

Abstract: PURPOSE:To obtain a covered electrode for providing excellent weld metal with high crack resistance, by containing a specified amount of Mn in the core wire, and adding a specified amount of Te and Se in either one or both of the core wire and a coating material made of specified component composition such as carbonate. CONSTITUTION:The captioned electrode is composed by containing the indispensable Mn; 0.9-2.2% in the core wire (in addition, Ni 5% or less, Cr 3% or less and Mo 1.5% or less may be contained by or more kinds to a total of 5% or less), and adding one or both of Te and Se to either one or both of the core wire and a coating material containing carbonate 10-60%, fluorine compound 1-30%, and the balance of deoxidizing agent of other than Mn and iron in ferro-alloy, within the range shown in formula I (in addition, rare earth elements may be added in the range shown in formula II), and then covering the core wire with the said coating material. This electrode is greatly reduced in the amount of diffuse hydrogen in the weld metal as compared with the conventional electrodes, and is improved in the crack resistance and weldability of the weld metal, so that it is ideal for welding of structural steel.