Showing papers by "Cabot Corporation published in 1979"

Method of heat treating nickel-base alloys for use as ceramic kiln hardware and product

Abstract: Disclosed is a NICRALY alloy containing nominally about 16% chromium, about 5.3% aluminum, about 0.02% yttrium and the balance essentially nickel, and heat treated in a manner to develop an essentially aluminum oxide surface. The NICRALY alloy is especially suited for use as components and support systems in kilns that are used in the firing steps in the manufacture of ceramic articles.

Wear-resistant iron-nickel-cobalt alloys

Abstract: Disclosed is a wear-resistant Fe-Ni-Co-base alloy that is suitable for use as coatings, sintered powder metal parts, and material for application of hard-facing depositions and/or plating. The alloy preferably contains about 11% cobalt, 24% nickel, 3% each molybdenum and tungsten, 26% chromium, 1.3% silicon, 1% carbon, about 0.5% boron, up to 4% modifying elements Mn, V, Ta, Cb, Cu, La, Zr, R-E metals, and the balance essentially iron plus incidental impurities.

Production of high surface area carbon blacks

Abstract: This disclosure relates to an improved furnace process for producing carbon blacks by the incomplete combustion of hydrocarbonaceous feedstock wherein the resultant blacks have higher surface areas than the carbon blacks normally prepared from the feedstocks, as a result of which the blacks are particularly suitable for use in imparting conductivity properites to plastic materials and the like. This disclosure also relates to the production of a novel class of furnace blacks having excellent conductivity properites and which are characterized by high surface areas and low pH values.

Slow Strain-Rate Technique and Its Applications to the Environmental Stress Cracking of Nickel-Base and Cobalt-Base Alloys

Abstract: The slow strain-rate technique (SSRT) was used to investigate the susceptibility of several nickel-base and cobalt-base alloys to environmental stress cracking. This technique was successful in revealing the stress corrosion cracking (SCC) tendency of a given alloy in a specific environment. Yet, the measurable quantities (percent elongation, percent reduction in area, load at failure, and the total time to failure) were not always consistent indicators of the SCC phenomenon nor of its severity. Metallographic examination allowed to quantify the susceptibility to SCC through the measurement of the average "secondary stress corrosion crack" depth. The effects of strain rate, solution temperature, and solution concentration were clearly established using the SSRT. However, the effect of cold work on the susceptibility to hydroxide stress cracking was inconclusive. Also, the SSRT was not able to distinguish the SCC phenomenon from that of a "stress assisted intergranular corrosion" occurring on sensitized material.

Method and system for the fractionation of ethane-propane mixtures

Abstract: Relatively high pressure mixtures consisting essentially of a major ethane component and a minor, but substantial, propane component are separated into relatively pure ethane and propane fractions by subjecting such mixtures to a number of specific cooling steps and an expansion step preparatory to and in combination with a fractional distillation step. The overhead ethane fraction of the method has a propane content of no greater than about 10 mole percent and is provided in the gas phase. The propane bottom fraction of the method is provided in the liquid phase.

Influence of Carbon Black on Processability of Rubber Stocks. II. Extrusion Shrinkage

Abstract: Extrusion shrinkage is caused by molecular relaxation of polymer after exit from the die. The rate of molecular relaxation is extremely rapid and under the present experimental conditions, 80% of limiting extrusion shrinkage, L∞, is reached in less than 10 sec. The dependence of extrusion shrinkage L, on time t may be expressed by an empirical equation: L=L∞(1−kt−n) where k and n are constants. An increase in relaxation temperature increases values of L∞ and decreases n, while increase in shear rate decreases constant k. As found previously, extrusion shrinkage, L∞, is related to shear stress. Maintaining a good uniformity of product in factory extrusion may be accomplished by controlling extrusion pressure as well as by speeding up and controlling the process of molecular relaxation. The latter goal may be attained by maintaining the extrudate at an elevated temperature for about 2 min, and controlling that temperature within narrow limits. The results show the importance of defining extrusion c...

Influence of Carbon Black on Processability of Rubber Stocks. IV. Kinetics of Extrusion Shrinkage

Abstract: A careful examination of post-extrusion relaxation rates of SBR compounds containing various carbon blacks has shown that two distinct relaxation processes are taking place. The fast recovery region observed at times of less than 0.1 s after exit from the die is thought to be due to solid-like elastic recovery of the polymer imposed in the extensional flow region at the entrance to the die. The magnitude of that recovery increases with increasing surface area and decreasing structure of carbon black. The slow recovery region is observed at times longer than 1 s and caused by molecular orientation that occurs mainly during the extensional flow at the die entrance and maintained during the viscous flow through the die. Carbon black surface area and structure do not significantly affect the magnitude of the shrinkage in the slow recovery region. The observed two relaxation mechanisms may be simulated mathematically by two modified Maxwell elements in parallel, whose spring constants (and relaxation ...

Oxidation resistant iron base alloy articles for welding

Abstract: An improved oxidation resistant iron base alloy article for welding to another article to form a composite product with reduced heat affected zone cracking is provided consisting essentially of about 0.05 to 0.7% carbon, less than 0.3% columbium, about 15 to 30% cobalt, about 18 to 25% chromium, about 0 to 2% manganese, about 1 to 6% molybdenum, about 0.10 to 0.30% nitrogen, about 15 to 30% nickel, about 0.2 to 0.6% silicon, about 0.1 to 2% tantalum, about 1 to 10% tungsten, about 0 to 0.1% zirconium, about 0 to 0.5% aluminum, about 0 to 0.1% lanthanum and the balance iron >23 w/o with incidental impurities not exceeding 0.6% in aggregate. The combined % of columbium and tantalum being at least 0.4% and the combined carbon and nitrogen being >0.2%.

Apparatus for vacuum casting of rods

Abstract: An apparatus for forming metal articles, such as rods and tubes by aspiration casting is provided in which a hollow frangible mold, such as a glass tube, is immersed at one end in a molten metal bath, a vacuum is applied to the other end controlled with respect to temperature of the molten metal so as to substantially fill the mold with a minimum of turbulence, the filled mold is withdrawn from the metal and the frangible mold is shattered to remove it from the metal article formed within.

Strength Specifications and Methods of Test for Structural Grades of Cryogenic Balsa Wood Insulation

Abstract: Balsa wood is a useful material for cryogenic applications owing to its relatively high structural strength and good thermal insulating properties that increase with decreasing temperatures. Balsa wood insulation has been used in overland transporters of cryogenic liquids,1 in cargo holds of LNG tanker ships,2 and in land-based LNG storage tanks.3 The construction and operation of such cryogenic liquid containers in many instances are subject to international, national, or local governmental regulations or industry codes, intended to insure sound industrial practice and public safety. Such codes or regulations typically include specifications for minimum structural properties of the materials of construction and frequently require mechanical testing of coupon specimens to demonstrate code compliance.