Showing papers on "Weldability published in 1974"

Some Aspects of the Influence of Manganese in Austenitic Stainless Steels

Abstract: The effect of Mn on the pitting corrosion resistance of 18 8 steels is due to its sulphide forming ability, because the sulphides are then present as non-metallic inclusions. As is shown by the authors that reduction of the manganese content of these steels (from normally 1.8% to values around 0.2) gives rise to a considerable improvement of the corrosion behaviour. The pitting potential is then displaced toward considerably higher values while no negative aspect is noted on a weldability and no increase of the ferrite content in the ascast and as-rolled conditions is experienced.

Ferritic stainless steels

Abstract: The present invention relates to high chromium ferritic stainless steels and more particularly to improving their chloride stress corrosion cracking resistance and weldability.

Method for producing a killed steel wire rod

Abstract: of the Disclosure: A method for producing high tensile strength steel wire rods and bars having a basic composition comprising; C 0.02 to 0.20% Si 0.03 to 0.90% Mn 1.00 to 1.85% together with one or more selected from the group consisting of with the balance being the iron and unavoidable impurities, which comprises heating a steel having above composition at a temperature not lower than 1150°C, conducting intermediate rolling and/or finish rolling at a temperature between 700 and 1050°C, controlling the cooling rate from finish of the hot rolling to a coiling to 40 to 350°C/sec., and controlling the cooling rate from the coiling to gathering to 1 to 15°C/sec. to obtain hot rolled steel wire rods and bars having excellent workability and spot weldability and having a tensile strength not lower than 50 kg/mm2 and a reduction of area not lower than 50%.

Oxidation-resistant ferrous alloy

Abstract: A low alloy steel for use as a substrate for aluminum or aluminum alloy coatings, the steel containing from 0.01% to 0.13% carbon, from 0.5% to 3% chromium, from 0.8% to 3% aluminum, from 0.4% to 1.5% silicon, from 0.1% to 0.6% manganese, from 0.1% to 1% titanium and remainder substantially iron. The steel has good oxidation resistance at elevated temperature, good weldability and formability, thereby enhancing its utility for fabrication into a variety of wrought coated products.

Effect of alloying of the seam metal on the properties of weldments in invar alloys

Abstract: 1. Alloys of iron with 36–42% Ni have good weldability and high physicomechanical properties at 4.2–293°K. 2. To increase the resistance of weld seams to hot cracking and porosities it is necessary to use filler wire alloyed with as much as 3.5% Mn, 1.5% Ti, and 4% Mo. Higher strength of welds is achieved by combined alloying with these elements and chromium (up to 5%). 3. An increase of the coefficient of thermal expansion to 4–5·10−6 deg−1 leads to thermal stresses near 5.0 kg/mm2 during thermal cycling in the range of 4.2–293°K. 4. In welded joints of Invar and stainless steel of the 18/8 type stresses around 40.0 kg/mm2 occur during thermal cycling, which amounts to 0.5σ0.2 of the weld metal at 4.2°K.

Properties of a new family of stainless steels without nickel

Abstract: Many applications in which stainless steels are employed call for good corrosion resistance and, at the same time, for good weldability. The new family of stainless steels which we propose to describe is related by its structure to the steels of the ferritic group and by its properties,i.e., the ductility of its welds and its corrosion resistance, to the steels of the 18-8 austenitic group. One type of analyses will be examined in particular: C max 0.1, Mn 3-6, Si 1-2, Ni max 1, Cr 15-18, Mo 0.5-2. The carefully defined combination of the chromium, molybdenum, silicon and manganese concentrations ensures, on the one hand, a hot-state structure similar to that encountered in AISI 430 or AISI 434 ferritic steels and, on the other hand, eliminated the transformation to martensite of the austenite present at high temperatures; in other words, it conserves the advantages inherent in a two-phase structure as far as hot transformation is concerned (no abnormal increase in grain size), while at the same time avoiding the deleterious effects subsequently caused by the appearance of a brittle martensitic phase. Structural study of the phases formed in these new steels as a result of different heat treatments clearly shows their new and distinctive place in the range of stainless steels known to date. The fabricating of these steels raises no difficulties. Special attention will be given to welding, an area in which this new family of steels offers specific advantages, and a number of application examples will be described.

マグネシウム量の少ないAl-Zn-Mg系合金の実用化に関する研究

Abstract: Extensive studies were carried out to develop new Al-Zn-Mg alloys with excellent extrudability, weldability, resistance to stress corrosion cracking and medium strength. Besides above properties, aging characteristic, corrosion resistance, resistance to weld cracking, strength of welded joints, fatigue strength, resistance-weldability and low temperature characteristic of several Al-Zn-Mg alloys with less Mg were investigated in detail. From these studies, the following two alloys were developed and put to practical use.The alloy, ZK60, with 6%Zn, 0.7-0.8%Mg, 0.1-0.2%Zr and Mn had better extrudability than common alloys with 4-5%Zn and 1-2%Mg and 6061. Strength, weldability and resistance to stress corrosion cracking of this new alloy was nearly equal to those of common Al-Zn-Mg alloys, when it was T5-treated.The alloy, ZK61, with 6%Zn, 0.3-0.4%Mg and 0.1-0.2%Zr was also developed and had remarkably good extrudability which was equivalent to that of 6063 alloy. Tensile and yield strength of the naturally aged alloy were 30 and 18kg/mm2, respectively and seemed to be higher than those of 5083 alloys. Weldability and corrosion resistance were similar to those of 5083 alloy. However, the alloy had better resistance to stress corrosion cracking and low temperature characteristics.These two alloys are currently and widely used as strength member of container, trailer, rolling-stocks, rims of auto-cycles and bicycles.

Properties of low-pearlitic steels with vanadium and niobium after controlled rolling

Abstract: 1. Raising the initial rolling temperature from 1050–1100 to 1200–1250° increases the strength characteristics due to the solution of carbonitrides; therefore, the effect of the increase in strength is stronger in the steel alloyed with vanadium and niobium, and is hardly manifest in the steel not containing these elements. 2. Lowering the final rolling temperature from 950 to 700° leads to higher strength characteristics, particularly final rolling at 700°. 3. Lowering the final rolling temperature lowers the ductile-brittle transition temperature (T50), i.e., increases the resistance to brittle fracture. However, the work of crack propagation decreases in this case, i.e., the resistance to ductile fracture. 4. The increase in strength and lower ductile-brittle transition temperature when the final rolling temperature is lowered are due to grain refining. However, the work of crack propagation decreases in this case (ap) and also the notch toughness at −40°. A final rolling temperature of 800° produces the best combination of mechanical properties. 5. The high values of the strength, ductility, and toughness in combination with a very low carbon equivalent lead us to consider low-pearlitic steels as promising materials for welded structures and materials requiring good weldability and resistance to fracture. Controlled rolling makes it possible to control the properties of these steels within wide limits by changes in the strength, ductility, and toughness, depending on the requirements.

Microstructure: property control with postweld heat treatment of Ti--6Al-- 6V--2Sn

Abstract: A major limitation in the use of Ti--6Al--6V--2Sn (Ti-662) as a structural alloy is its poor weldability. After convertional postweld heat treatment, the weld has very low ductility. However, proper postweld heat treatment will develop good ductility and fracture toughness in welded Ti-662. It is important to develop the correct microstructure, since mechanical properties depend upon the morphology of the alpha phase. Superior tensile ductility and fracture toughness were achieved with a duplex alpha-plate structure produced by a triplex heat treatment of automatic GTA welded 0.125-in. sheet. Matching filler metal gave better properties than Ti--8Al-4V filler. (11 figures, 4 tables) (auth)