Showing papers on "Shot peening published in 1978"
Patent•
12 Sep 1978TL;DR: A method of increasing the fatigue life of a metal part of a titanium alloy by subjecting it to the steps of abrasive cleaning and shot peening is described in this article.
Abstract: A method of increasing the fatigue life of a metal part of a titanium alloy by subjecting it to the steps of abrasive cleaning and shot peening.
21 citations
Patent•
21 Apr 1978
TL;DR: In this article, the authors proposed a method to enhance the hot steam oxidation resistance of an austenitic stainless steel pipe by specifying the cold working ratio of the pipe and the heating condition in soln. heat treatment.
Abstract: PURPOSE:To enhance the hot steam oxidation resistance of an austenitic stainless steel pipe by specifying the cold working ratio of the pipe and the heating condition in soln. heat treatment and organically combining the cold working and heat treatment. CONSTITUTION:An austenitic stainless steel pipe is subjected to cold working such as grinding, metal brushing or shot peening at a working ratio above 20%. The cold worked pipe is then heated to 1000 - 1200 deg.C at a heating rate below 2.9 deg.C/set to carry out soln. heat treatment. The resulting pipe does not undergo stress corrosion cracking and deterioration in creep rupture strength and does not form scale even if exposed to hot steam over a long time. Thus, the pipe has enhanced hot steam oxidation resistance.
8 citations
TL;DR: In this paper, shot peening was used to improve the corrosion fatigue life of AISI 6150 steel in a 3 pct NaCl environment, and the average size of the fatigue initiation facets in the peened specimens was much smaller than that of the unpeened specimens.
Abstract: Reversed-bending fatigue tests of quenched and tempered AISI 6150 steel were conducted in dry air and in aqueous 3 pct NaCl. The 3 pct NaCl environment drastically reduced fatigue life but two different shot peening treatments were found to improve the corrosion fatigue life over that of unpeened samples. Multiple fatigue crack initiation occurred at very distinct locations in both the unpeened and the peened specimens fatigued in 3 pct NaCl. Fatigue crack propagation from each initiation site occurred first on flat facets normal to the stress axis and then by a more ductile mechanism after the initiation facets had linked. The average size of the corrosion fatigue initiation facets in the peened specimens was much smaller than that of the unpeened specimens; however, the number of initiation sites was greater in the peened specimens. It is believed that the beneficial effect of the shot peening results from significantly reduced early fatigue crack propagation rates in the compressive residual stress layer at the surface.
8 citations
Patent•
11 Sep 1978
TL;DR: In this article, JPO&Japio proposed a method to strengthen the fillet portio without producing a curve in the crankshaft, by means of lathe turning to construct a fillet portion 4 in the manner of drive into corner.
Abstract: PURPOSE: To totally strengthen the fillet portio without producing a curve in the crankshaft, by means of lathe turning to work the fillet portion to an arc, that circumscribes inside face of the web and outside diameter face of the crank pin, to process the work of shot peening. CONSTITUTION: Inside face of a web 2 and outside diametrical face of a crank pin 3 are processed a lathe turning, to construct a fillet portion 4 in the manner of drive into corner. The fillet portion 4, processed a lathe turning in the manner of drive into corner, is processed a work of shot peening almost simultaneously with a work of high frequency quenching for an inside face 2' and outside diametrical face 3', with the fillet portion 4 totally strengthened. An arc 4', strengthened by the work of shot peening, without being removed and cut, can be highly kept a strength of fatigue. COPYRIGHT: (C)1980,JPO&Japio
7 citations
TL;DR: Peen forming has been used in the special field of the airplane industry as discussed by the authors and has been applied successfully to strong brittle materials which are difficult to form because it has a feature of forming under compressive stresses.
Abstract: Peen forming has been utilized in the special field of the airplane industry. The authors conceive independently the principle of this process and intend to develop this as a general forming process of sheet metals. Suitable selection of peening conditions such as the diameter or the velocity of a shot enables bulging of a disc and bending of a strip. Successful conditions in these formings depend on the peening energy of a grain of shot and there exist a lower and an upper limit of the energy. When the upper limit is exceeded, the disc sinks and the strip bends in the opposite direction. So, the intended forming cannot be attained. Peening brings about a strengthening through work-handening and a roughening of the products. This process is applied successfully to strong brittle materials which are difficult to form because it has a feature of forming under compressive stresses.
7 citations
Patent•
19 Oct 1978
TL;DR: In this article, a shot is composed of Cr carbide distributing as a net and particles of carbide exhibited in basic martensite and bainite as shown in the table.
Abstract: PURPOSE: To treat a stainless steel pipe effectively by distributing Cr carbide in the state of a net in shot to have the efficiency of toughness. CONSTITUTION: This shot is composed of Cr carbide distributing as a net and particles of carbide exhibited in basic martensite and bainite as shown in the table. The high hardness and toughness may be attributed to the metallic composition. The usual white pig iron has an inclination of easy cracking though hard due to the combined constitution of cementite and pearlite. The shot is used to give the effective shot peening of stainless steel pipe or the like. COPYRIGHT: (C)1980,JPO&Japio
4 citations
Patent•
01 Aug 1978
TL;DR: In this paper, a vane wheel is put into a tube to be treated, in the manner that it can be freely moved along the length of the same, whereby uniform shot peening treatment can be applied along the entire length of a long tube.
Abstract: PURPOSE:To provide a method of shot peening, according to which a vane wheel is put into a tube to be treated, in the manner that it can be freely moved therein along the length of the same, whereby uniform shot peening treatment can be applied along the entire length of a long tube.
3 citations
Patent•
[...]
14 Oct 1978
TL;DR: In this article, a material is subject to shot peening as it is tensed in the direction of the length thereof by a restraining jig and obtain a stable shot-peening effect without creating distortion and warping.
Abstract: PURPOSE:To subject a material to shot peening as it is tensed in the direction of the length thereof by a restraining jig and obtain a stable shot peening effect without creating distortion and warping in the material.
3 citations
Patent•
09 Aug 1978
TL;DR: In this article, the surfaces of the dovetail pins 3 inserted into pin holes 6 equipped on a rotor and a blade 2 are shot peened by a shot peening material of more than the Vickers hardness of at least 1000 on the surface.
Abstract: PURPOSE: By increasing the delay breaking strength of, for example, jointing pins (dovetail pins) of rotors and running blades of a steam turbine by use of shot peening materials of more than the Vickers hardness of at least 1000, breaking damage is prevented. CONSTITUTION: The surfaces of dovetail pins 3 inserted into pin holes 6 equipped on a rotor 1 and a blade 2 are shot peened by a shot peening material of more than the Vickers hardness of at least 1000 on the surface. In this method delay breaking strength of the dovetail pins 3 is increased and breaking damage is prevented. COPYRIGHT: (C)1980,JPO&Japio
Patent•
19 Jan 1978
TL;DR: In this paper, the distance between an internal peripheral surface and a shor jet nozzle, and a machining time at each point of the surface, was maintained constant and uniform.
Abstract: PURPOSE:To maintain constant the distance between an internal peripheral surface and a shor jet nozzle, and a machining time at each point of the surface, and keep uniform the depth of a machined hardened layer formed on the internal peripheral surface thereby to obtain an article of homogeneousness.