Showing papers on "Weldability published in 1982"

Physical and Mechanical Properties of High Manganese Non-magnetic Steel and Its Application to Various Products for Commercial Use

Abstract: In order to develop new high manganese non-magnetic steels that can be employed to extensive applications ranging from cryogenic to elevated temperature uses, the effects of C and Mn on their magnetic permeability, thermal expansion coefficient and mechanical properties are investigated.It is found that the relation between thermal expansion coefficient, β, and both C and Mn contents can be expressed by the following linear regression equation: β(×10-6/°C)=17.66+3.82C(%)-0.22Mn(%). Good mechanical properties are exhibited in the wide range of Mn contents between 18% and 30% at room temperature, while there is a tendency that this optimum range of Mn content is narrowed at cryogenic temperature.Then, H-shapes, round bars and deformed bars are manufactured at the workshops using 5t vacuum melted ingots, aiming to establish the conditions for practical processes for final products and to study such various characteristics of the products as their physical and mechanical properties, machinability and weldability. As a result, it is shown that all of those products have excellent properties as non-magnetic steels.In addition, the manufacturing of non-magnetic pinch rolls attached to the electro-magnetic stirring equipment on the continuous casting machine is described in detail as one of the practical applications of the high Mn non-magnetic steels.

A Thermophysical Criterion for the Weldability of Electric Contact Material in a Steady-State Regime

Abstract: A thermophysical criterion for the weldability of contact materials is determined as an unambiguous function of the fusion temperature and of the temperature dependences of the resistivity and thermal conductivity of these materials. The values of this criterion are calculated for most metals, a number of alloys, and some of sintered compounds usually applied in contact design. Also calculated is the dependence of the criterion on the preheating of the contact body, which is important for the estimation of weldability under conditions of circuit reclosing in the presence of a short circuit. Some limitations of the recalculation of the weldability criterion for conductors not mentioned in this paper are discussed.

Production of al-zn-mg alloy having excellent weldability and resistance to stress corrosion cracking

Abstract: PURPOSE: To obtain an Al-Zn-Mg alloy having excellent weldability and resistance to stress corrosion cracking by specifying the content of elements to be added in a very slight amt. in an Al-Zn-Mg alloy to form fine-sized crystal grains and subjecting the alloy to a heat treatment under a specific condition. CONSTITUTION: An alloy contg. 3.0W8.0wt% Zn, 0.3W3.0% Mg, 0.005W0.20% Ti, 0.0005W0.5% B and consisting of ≥2 kinds among 0.03W0.5% Cu, 0.03W0.5% Ag, 0.03W0.5% Ni, 0.2W0.7% Si, ≥1 kind among 0.05W0.40% Mn, 0.05W0.40% Cr, 0.05W0.25% Zr and the balance Al is cast and the crystal grain size thereof is reduced to ≤1,500μ. The cast ingot of such alloy is subjected to a homegenization treatment at 400W550°C and hot rolling at ≥60% reduction ratio at 350W 500°C so that the ratio between the short diameter and long diameter of the crystal grain after the final heat treatment is made ≥1:5 and the length of the short diameter at ≤80μ. The Al-Zn-Mg alloy for structural material having excellent resistance to stress corrosion cracking in the weld zone thereof is thus obtd. COPYRIGHT: (C)1984,JPO&Japio

Spot-weldable lightweight composite material

Abstract: A lightweight composite material consisting of two metal sheets and an intermediate layer consisting of a mixture of resin and graphite and held between the metal sheets. The intermediate layer has a specifically limited thickness and a specifically limited graphite content, and the graphite has a specifically limited particle size distribution. The composite material is excellent in the spot weldability, bending rigidity, vibration-damping property and heat insulating property, and can be expected to be widely used as a material for automobile and further materials for industrial machine and architecture.

New fluxes of improved weld metal toughness for HSLA steels

Abstract: Weld metals which are microalloyed with Ti and B can show excellent properties even at low temperature. However, welding consumables which can consistently add optimum amounts of Ti and B to weld metal were relatively unknown. Therefore, new TiO/sub 2/-B/sub 2/O/sub 3/ bearing fluxes, which can add Ti and B to weld metal by reduction of their oxides in the fluxes, were developed. When TiO/sub 2/ was a main component, it was necessary to substitute BaO, MgO or some other basic component for CaO in order to eliminate the precipitation of perovskite (CaTiO/sub 3/) and have a good weldability. The new fluxes were shown to be able to consistently microalloy weld metals with optimum amounts of Ti and B (about 0.02% and 0.0045%, respectively). Fracture appearance transition temperature of the weld metals was sufficiently low and only slightly deteriorated with the addition of Nb in the as-welded metal. The new fluxes were successfully applied to the welding of node cans of offshore platforms, a sea berth, LPG tanks and ships.

Spot Weldability of High Strength Steel Sheets

Abstract: 高強度薄鋼 板を 自動車用鋼板 と して 使用 する 場合 に は,成 形後溶接 され る例がほ とん どである.し たがつて 成形性のみな らず溶接性 のす ぐれた高強度 薄鋼板 の開発 が望 まれている.そ の溶接法 もスポ ッ ト溶接,ア ー ク溶 接,ろ う付 け等 と種類 も多 く,し か も薄板 の溶接 を考え る時には母材 材質 のみな らず,溶 接機 器の性能,継 手形 状,溶 接条件 など考慮すべ き重要 な因子 も多い.こ れ ら については 田村 の す ぐれた 解説があるので 参照 された い 1). そ こで本講 では最近関心の高い 自動 車用 高強度薄鋼板 のスポ ッ ト溶接性に的を絞 り,こ れに影響 を 与え る要因 および溶接 部品質評価方法(表1)の うち主 なもの につ いて最近の成果を まとめる 2). なお防錆用鋼板は実用上 ます ます重要 となる鋼板 であ り,し か も溶接上 の問題点 も多いが1),そ の品種 も流動 的 であ り,ま た報告 も少ない3)4)ので省略す る.

High strength aluminum alloy having superior stress corrosion cracking resistance at flash butt weld zone

Abstract: PURPOSE: To provide a high strength Al alloy consisting of prescribed precentages of Zn, Mg, Cu and one or more among Mn, Cr, Zr, etc. and the balance Al with impurities and having high strength and superior stress corrosion cracking resistance at its flash butt weld zone. CONSTITUTION: This high strength Al alloy consists of, by weight, 3W9% Zn, 0.3W2.5% Mg, <0.6W2.0% Cu, one or more among 0.05W0.6% Mn, 0.05W0.3% Cr, 0.05W0.25% Zr, 0.005W0.25% V, 0.001W0.1% Ti and ≤0.05% B, and the balance Al with impurities. This Al alloy is used to reduce the wieght of a car, a bicycle, etc., and it has high strength, very satisfactory stress corrosion carcking resistance at its flash butt weld zone as well as its base metal part, and superior flash butt weldability. COPYRIGHT: (C)1983,JPO&Japio

An examination of chromium substitution in stainless steels

Abstract: A series of lower Cr stainless steels containing various levels of Mo, Si, Cu, V, N, and Ni were examined. In less severe environments it was possible to achieve corrosion resistance comparable to 18-8 type stainless steels in alloys containing about 9 pct Cr, along with additions of Ni, Mo, Cu, and V. The hot working behavior, weldability, and mechanical properties appear comparable to conventional grades of stainless. Alloys of this type could be used in decorative, aqueous, and some industrial applications, but should not be adequate for more severe environments.

Weldable paint-coated steel sheets having excellent corrosion resistance

Abstract: A weldable paint-coated steel sheet having improved corrosion resistance, weldability and workability, comprising a zinc alloy coated steel substrate and a paint coating applied thereon, said paint coating containing zinc alloy powder and at least one of the groups consisting of zinc powder and hard electric conductive powder.

Preparation of molten zinc plated steel plate excellent in weldability

Abstract: PURPOSE:To prevent Al-concentration on the surface of a molten zinc plating layer to enhance the spot weldability of a molten zinc plated steel strip, by heating the molten zinc plated steel strip to a specific temp. after quenching the same by injecting water. CONSTITUTION:A steel strip is passed through a molten Zn-bath containing 0.07-0.17% of Al to adhere molten zinc to the surface thereof and the amount to be adhered of molten Zn is adjusted by injecting inert gas from a gas wiping nozzle 3. Succeedingly, the plated steel strip is cooled by spraying water or an aqueous solution containing various metal chlorides from a spray nozzle 41 thereto to solidify the plated layer while the Al-concentration in molten Zn adhered to the surface of the steel strip is prevented. In the next step, the treated steel strip is introduced into a heating furnace 5 having an atmosphere containing 1% or more of oxygen and water is sprinkled to the surface thereof or steam is blown into the furnace while held to 200-400 deg.C for 30sec or more to form thin Zn-oxide film on the surface of the Zn-plating layer and the resulting plated steel strip is wound up while cooled by a conditioning cooling furnace 6. Because zinc oxide is present on the surface of the Zn-plating layer, the consumption of a copper electrode in spot welding is reduced.

A 2¼Cr-1Mo Pressure Vessel Steel with Improved Creep Rupture Strength

Abstract: In the ASME Boiler and Pressure Vessel Code, Sec. VIII, Div. 1, design allowable stress-intensity values are influenced by the creep rupture strength at temperatures higher than 450°C. Pressure vessels for such high-temperature service inevitably tend to be thickwalled unless a steel with high creep strength is used. In the case of a coal liquefaction reactor, for instance, a possible wall thickness would be approximately 300 mm or even greater with the use of conventional 21/4Cr-1Mo steel (SA336 F22). The objective of the present work was to develop a heavy-section 2 1 / 4 Cr-1Mo steel with better creep strength by conducting a set of experiments with regard to the effect of microalloying elements. The best composition to obtain improved creep-rupture properties was found to be low Si-0.10C-2 1 / 4 Cr -1Mo- 1 / 4 V-Ti-B. With this composition, remarkable reduction in temper embrittlement susceptibility was also achieved. Other properties, such as weldability, low temperature toughness, and hydrogen embrittlement resistance, were similar to those of conventional 2 1 / 4 Cr-1Mo steel.

A new low-carbon 16Cr-5Ni stainless martensitic cast steel

Abstract: A new low-carbon 16Cr-5Ni stainless martensitic cast steel (S+C 4405) is presented as an advancement of CA6NM with improved corrosion resistance, excellent ductility, less susceptibility to hardening cracks, and good weldability, filling the gap between CA6NM and CF8M. The chemical composition is balanced so that a homogeneous microstructure consisting of annealed martensite with small amounts of δ-ferrite and finely dispersed austenite is obtained after hardening and tempering. Because of limited δ-ferrite, the impact values obtained correspond to CA6NM, and limited austenite still allows yield strength values comparable to those of CA6NM. Due to its excellent ductility combined with good fabricability, the material is also suitable for cryogenic applications down to -200°C. Furthermore, favorable fatigue tests, and particularly test results in artificial seawater, show a remarkable improvement over CA6NM. Pitting- and crevice-corrosion tests by the International Nickel Co. multiple-crevice tetrafluoroethylene washer method suggest a corrosion resistance between that of CA6NM and CF8M and that this steel is suitable for seawater application in connection with cathodic protection. Stress-corrosion cracking in hydrogen sulfide-containing media was investigated according to the National Association of Corrosion Engineers Specification MR-01-75, and the resistance of 16Cr-SNi under sour-gas conditions was found to be superior to that of CA6NM. The castability of this alloy was found to be favorable and comparable to that of CA6NM. These characteristics are important for the following applications: offshore engineering, seawater desalination, chemical and petrochemical industries, shipbuilding, cryogenics, power generation, food industry, paper machine construction, and especially for pumps, compressors, fittings, centrifuges, waterturbines, and ship propellers.

Preparation of al-mg-si alloy for processing excellent in corrosion resistance, weldability and hardenability

Abstract: PURPOSE: To obtain an Al-Mg-Si alloy for extrusion processing excellent in corrosion resistance, weldability and hardenability, by properly controlling thermal conditions in homogenization, hot processing, hardening and ageing treatments of an Al-Mg-Si alloy ingot with a specific composition. CONSTITUTION: An alloy ingot comprising 0.5W1.0% Si, 0.5W1.4% Mg, 0.30W 0.55% Cu, 0.01W0.20% Ti, 0.15%W0.40% Fe, 0.04W0.50% Mn, 0.04W0.30% Cr, 0.04W0.30% Zr and the remainder Fe and impurities and adjusted to 0.7W2.0 in Mg/Si and 0.3W0.7% in Fe+Cr+Mn+Zr is obtained. This ingot is heated at a temp. rising speed of 200°C/hr or less and held at 480W575°C for one hr or more to be subjected to homogenization treatment. In the next step, the heat treated ingot is subjected to hot processing at 460°C or more and cooled at a cooling speed of 80°C/min or more to be hardened. Succeedingly, the hardened ingot is held within a range of 130W220°C for 0.5W15hr to carry out artificial ageing treatment. By these treatment conditions, an Al-Mg-Si alloy for processing improved in strength, tenacity, corrosion resistance, weldability and hardenability is obtained. COPYRIGHT: (C)1983,JPO&Japio

Process of electroplating a nickel-zinc alloy on steel strip

Abstract: An electroplating process is disclosed for coating metal strip or sheet with a nickel-zinc alloy comprising at least 80% nickel Steel sheet coated with the alloy exhibits excellent weldability

Evaluation of spot weldability of high-strength sheet steels for automobile use

Abstract: Description des essais de traction sur des toles soudees par points: essais sur des eprouvettes en U, essais de cisaillement, essais de pelage

Highly corrosion resistant surface treated steel plate

Abstract: PURPOSE: To obtain a titled steel plate having good corrosion resistance, paintability, and weldability by carrying out electroplating of metals (alloys) of Zn, Ni, etc. on the surface of a steel plate and forming a diffusion layer of said metals (alloys) by heating in the steel then carrying out plating of a Zn-Ni alloy on the surface of the steel plate. CONSTITUTION: Metallic plating of Zn, Ni, Sn, Cr or consisting essentially of these metals is carried out thinly on both front and rear surfaces of a steel plate. The plating in this case is carried out preferably at 0.5W20g/m 2 per one side. The steel plate after the plating is heated in a nonoxidative atmosphere to diffuse said plating metal thoroughly into the steel. Zn-Ni alloy plating is carried out on at least one surface of the steel plate formed with the diffused layer, whereby the intended surface treated steel plate having high corrosion resistance is obtained. The Zn-Ni alloy plating has a sacrificial effect of preventing corrosion when the content of Ni is 10W20wt% and is the range where the corrosion resistance is high. COPYRIGHT: (C)1983,JPO&Japio

Welded steel chain

Abstract: A steel with good weldability and hardenability, a yield point of at least 600 MPa, a rupture limit of at least 900 MPa at room temperature and an impact toughness of at least 40 Joule at -20° C., has the following chemical composition as % by weight: C: 0.03-0.07 Si: 0.10-1 Mn: 1.2-2.5 Cr: 1.8-3 Ni: 1.5-3 Mo: max 0.5 Nb, V, Ti total 0-0.10 with the remainder mainly only iron and impurities in normal amounts. The best impact toughness in achieved when the ratio Mn/Cr is about 2/3 or 0.6. The total content of Mn+Cr is, in accordance with a preferred embodiment, between 3 and 5, suitably between 3.5 and 4.5%. The steel is particularly suitable for anchor chains for e.g. off-shore oil drilling platforms. A recommended heat treatment after welding includes normalizing at 800°-1000° C., cooling to room temperature and duplex annealing.

Friction weld ductility and toughness as influenced by inclusion morphology

Abstract: Friction welding consistently provides high strength, freedom from fusion defects, and high productivity. However, friction welds in carbon steel exhibit impact toughness and bend ductility that are significantly lower than that of the base metal. The inclusion content and morphology were suspected to be major contributors to the reduction in weld ductility. For this reason, four electric furnace steels - three types of ASTM A516 Grade 70, and an ASTM A737 Grade B steel - were investigated. Friction welds were made by both the inertia and direct drive process variations and the welds evaluated. It was shown that friction welds of inclusion-controlled steels exhibited much improved toughness and bend ductility were demonstrated. Upper shelf impact energy was equivalent to or greater than that of the base metal in the short transverse direction. The transition temperature range for all four materials was shifted to higher temperatures for both types of friction welds. Under the conditions of this test, the direct drive friction welds showed a greater shift than the inertia friction welds. The ductility and toughness of welds in A737 Grade B steel were superior to welds in A516 Grade 70 steels, reflecting the superior properties of the base metal. Weldsmore » of the A737 material had usable Charpy V-notch impact toughness of 20 to 30 ft-lb (27 to 41 J) at temperatures as low as -40/sup 0/F (-40/sup 0/C). All the welds had an acicular structure. The differences in properties between the inertia and direct drive friction welds appear associated with microstructural variations. These variations resulted from the different heat inputs and cooling rates of the two process variations were demonstrated. The beneficial effects of inclusion control on toughness and ductility. In addition, it also indicates that additional improvements may be attainable through control of the as-welded microstructure by process manipulation.« less

Steel for pressure vessel with superior disbonding resistance

Abstract: PURPOSE: To obtain the titled steel with improved weldability in build-up welding, by further reducing the C content in one or both of only the surface layers of an Mo or Cr-Mo steel plate consisting of prescribed percentages of C, Si, Mn, Cr and Mo and the balance Fe. CONSTITUTION: This Mo or Cr-Mo steel for a pressure vessel consists of, by weight, 0.05W0.30% C, ≤1.00% Si, 0.20W1.60% Mn, ≤3.50% Cr, 0.30W1.50% Mo and the balance Fe with inevitable impurities. The C content in one or both of only the surface layers of the steel having 0.5W3mm thickness is essentially restricted to <0.05% C. When one side or both sides of the steel are clad with a steel material different from the steel in composition by build-up welding or other method, the steel has high weldability, does not cause exfoliation and cracking due to hydrogen during use in an H 2 atmosphere, and shows superior disbonding resistance. COPYRIGHT: (C)1983,JPO&Japio

Surface treated steel sheet having high corrosion resistance and its production

Abstract: PURPOSE: To obtain a laminated steel sheet having excellent corrosion resistance, weldability, etc. by forming a specific amt. of Zn plating layer on a steel sheet and further forming a specific amt. of a Co-W plating layer having a specific compsn. ratio thereon. CONSTITUTION: Zn or Zn alloy plating is applied on a steel sheet to form a plating layer of about ≥3g/cm 2 , more preferably 3W60g/m 2 coating weight. The steel sheet is then subjected to electroplating in a cobalt plating bath contg. 10W100g/l Co and 0.01W10g/l W or Cr to form a Co-W or Co-Cr alloy plating layer of 0.01W10wt%, more preferably 0.05W5wt% content of W or Cr so that the coating weight thereof attains 0.003W3g/m 2 , more preferably 0.01W1g/m 2 . The surface treated steel sheet having the excellent bare corrosion resistance and the excellent corrosion resistance after painting and the excellent weldability is thus obtd. COPYRIGHT: (C)1984,JPO&Japio

Stainless steel having resistance to hydrogen sulfide

Abstract: PURPOSE:To obtain a stainless steel with 210-248 Vickers hardness, 50-63.3kg/ mm. yield point, high resistance to hydrogen sulfide, high weldability and toughness by adding a specified amount each of C, Si, Mn, Ni and Cr. CONSTITUTION:The composition of a stainless steel is composed of, by wt., <0.03% C, <1% Si, <1, especially 0.4-0.6% Mn, 3-5% Ni, 15.5-17.5% Cr and the balance Fe with inevitable impurities. The steel is heat treated by hardening and tempering. The hardening temp. is regulated to 950-1,040 deg.C, and after water cooling or oil quenching from the temp., the steel is tempered by heating to 570-610 deg.C and air cooling.

Effects of Carbon Content and Tempering Treatment on the Mechanical Properties and Sulfide Stress-Corrosion Cracking Resistance of AOD-Refined CA6NM

Abstract: Cast Alloy CA15 is presently being used in sour gas environments in accordance with National Association of Corrosion Engineers (NACE) Standard MR-01-75, which requires that the maximum hardness not exceed Rockwell C22. There has been effort to replace CA15 with CA6NM, which has improved toughness properties. However, the 22HRC maximum has been difficult to reproduce in CA6NM. The argon oxygen decarburization (AOD) method of refining stainless steel produces a material with excellent impact properties and allows lower carbon levels to be consistently achieved that were previously difficult to attain. Charpy impact values and tensile properties are described, comparing AOD versus conventional methods of melting. An experimental hardness correlation has been suggested for the alloy. A new version of CA6NM with 0.03 percent maximum carbon, which may appropriately be called CA3NM, shows excellent sulfide stress-cracking (SSC) resistance using the standard NACE test. A threshold value in excess of 90 percent of material yield strength was achieved. The AOD method of refining improves mechanical properties, including toughness, and allows low carbon contents to be achieved with ease. Resultant lower hardness values can then be attained which satisfy NACE requirements for SSC applications.

High-cr low-ni two-phase stainless steel

Abstract: PURPOSE:To improve the corrosion resistance of a high-Cr low-Ni 2-phase stainless steel, especially the resistance to local corrosion such as pitting corrosion by adding a specified very small amount of B to the steel without changing the principal composition to inhibit the precipitation of alpha phase. CONSTITUTION:The composition of a 2-phase stainless steel is adjusted to, by wt., 0.01% B the effect is remarkable, yet the workability such as the weldability is deteriorated.