Showing papers on "Pearlite published in 1971"
01 Feb 1971
TL;DR: In this article, the authors compared tensile and notch-impact properties in wrought steel with and without elongated inclusions and processed so as to be severely banded or virtually free of microstructural banding.
Abstract: Tensile and notch-impact properties in wrought steel containing 0.25 pct C and 1.5 pct Mn, with and without elongated inclusions and processed so as to be severely banded or virtually free of microstructural banding, are compared. A short-time, high-temperature normalizing treatment removed the banded condition. Both banding and elongated inclusions cause anisotropy in tensile ductility and impact energy. Elimination of banding is effective in reducing anisotropy in clean steel, but results in only modest improvement in steel containing numerous elongated inclusions. Eliminating microstructural banding alters austenite transformation to only a small extent but improves subsequent machining and cold forming by replacing martensite concentrated in bands with randomly dispersed small volumes of martensite in steel incompletely transformed to ferrite and pearlite or to bainite.
143 citations
Patent•
24 Jun 1971
TL;DR: In this paper, the authors describe a scenario in which a car is driven at high speed from a rolling mill and formed into non-concentric overlapping loops on a conveyor.
Abstract: IN THE TREATMENT OF ROD TRAVELLING AT HIGHSPEED FROM A ROLLING MILL AND FORMED INTO NON-CONCENTRIC OVERLAPPING LOOPS ON A CONVEYOR, THE ROD IS NOT POSITIVELY COLLED BEFORE IT IS FORMED INTO THE OVERLAPPING RINGS, AND IS ALLOWED TO COOL NATURALLY ON THE CONVEYOR UNTIL IT IS ONLY A LITTLE ABOVE THE AUSTENITE TRANSFORMATION TEMPERATURE, SO THAT THE AUSTENITE GRAINS CAN GROW TO MIXIMUM SIZE. WHEN IT IS ON THE CONVEYOR THE ROD IS COLLED BY AIR AT A RATE OF AT LEAST 700 C., WITH THE OVERALL TEMPERATURE RANGE OF 750 TO 500* C., WITH THE OVERALL RESULT THAT THE PRECIPITATION OF GRAIN-BOUNDARY FERRITE IS MINIMIZED AND FINER AND MORE UNIFORM PEARLITE IS PRODUCED.
8 citations
TL;DR: AISI 4140 steel has been etched in aqueous picric acid containing a wetting agent to show up the prior austenite grain boundaries for a wide range of quenching and tempering treatments as mentioned in this paper.
8 citations
Patent•
07 Jun 1971
TL;DR: In this article, a hot-rolled rod with alternate quenching and heat compensation stages was used to transform to the pearlite zone before full temperature equalisation, the rod being reeled when a substantial peripheral zone of the rod has been predominantly transformed to pearlite.
Abstract: Patenting hot-rolled rod with alternate quenching and heat compensation stages before transformation; the quenching stations decrease logarithmically and the compensation stages increase logarithmically; the surface of the rod reaches is cooled down to below about 400*C, and the rod begins to transform in the pearlite zone before full temperature equalisation, the rod being reeled when a substantial peripheral zone of the rod has been predominantly transformed to pearlite.
8 citations
Patent•
30 Jun 1971
TL;DR: In this article, the CaFeAl alloy has been inoculated with a CaFeFeAl Alloy during casting, the alloy having the compn. 20% Ca, 40% Al, 40%, 40% Fe.
Abstract: The cast iron, contg. 1.5-3.5% Al as a replacement for Si, contains pearlite stabilizing elements selected from the gp: Sn, Cu, Cr, Mo or V, and in addition 2.5-4.2% C, 0.01-0.8% Si, 0.2-0.9% Mn, 0.3% P, 0.15% S. The alloy is inoculated with a CaFeAl alloy during casting, the CaFeAl alloy having the compn. 20% Ca, 40% Al, 40% Fe.
6 citations
01 Jan 1971
TL;DR: In this article, the various phases present in a sintered 4640 steel prepared from both mixed elemental and prealloyed powders have been identified, and the results indicate that only ferrite and pearlite are present in either material in the as-sintered (1/2 hour at 2050 F) condition.
Abstract: The various phases present in a sintered 4640 steel prepared from both mixed elemental and prealloyed powders have been identified. The results indicate that only ferrite and pearlite are present in either material in the as-sintered (1/2 hour at 2050 F) condition. Electron microprobe results indicated that the nickel concentration varied from 0–11% and molybdenum varied from 0–0.5% in the premixed specimens. Little or no compositional variation was found in the prealloyed specimens.
2 citations
TL;DR: In this article, a volumetric method was used to study the formation of microcracks during plastic deformation of annealed and normalized steel 70, and it was found that the number of micro-cracks formed increases with the coarseness of the original structure.
Abstract: The volumetric method was used to study the formation of microcracks during plastic deformation of annealed and normalized steel 70. It was found that the number of microcracks formed increases with the coarseness of the original structure. Defects occurring with substantial plastic deformation of annealed steel with a structure of coarse lamellar pearlite are healed by brief heating to temperatures above 1100°.
2 citations
Patent•
27 Sep 1971
TL;DR: A new cast iron and article of manufacture was made in the early 1800s as mentioned in this paper, and a new set of men from the group PEARLITE and BAINITE and a complete carbidic structure consisting of BORON NITRIDES, BORon CARBIDES, and other BORONS.
Abstract: A NEW CAST IRON AND ARTICLE OF MANUFACTURE MADE THEREFROM IS PROVIDED HAVING UNUSUAL ABRASIVE RESISTANCE AND AN ORIENTED LAMELLAR STRUCTURE CONSISTING OF AT LEAST ONE MEMBER FROM THE GROUP PEARLITE AND BAINITE AND A COMPLEX CARBIDIC STRUCTURE CONSISTING OF BORON NITRIDES, BORON CARBIDES AND OTHER BORON COMPOUNDS.
2 citations
TL;DR: The optimum combination of strength characteristics in carburized sintered iron with a hypereutectoid case structure and 15% of pores was achieved after quenching in water and tempering at 300°C as discussed by the authors.
Abstract: 1.
The optimum combination of strength characteristics in carburized sintered iron with a hypereutectoid case structure and 15% of pores is achieved after quenching in water and tempering at 300° C (σc=134, σt=62, σb=145 kg/mm2). Thus, the tensile and bend strengths of porous steel tempered at 300°C are more than twice those of untempered porous steel before and after quenching.
2.
The optimum combination of ductility and impact strength characteristics in steel with 15% of pores, resulting from the formation of a granular temper pearlite structure, is achieved by quenching in water and subsequent tempering at 600° C (δ=7.6%, ak=1.1 kg-m/mm2).
1 citations