摘要:
Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area; and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torqueing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.
摘要:
A method for producing a steel component by performing the treatments of the following sequentially steps 1 and 2 to a steel material containing, by mass %, C: 0.15 to 0.25%, Si: 0.01 to 0.10%, Mn: 0.50 to 0.80%, S: 0.003 to 0.030%, Cr: 0.80 to 1.20%, Mo: 0.30 to 0.45%, Al: 0.015 to 0.050%, and N: 0.010 to 0.025%, wherein Cr/Mn is 1.3 to 2.4, the balance being Fe and impurities, and contents of P and O among the impurities are P: not more than 0.010%, and O: not more than 0.0020%: step 1: a treatment which holds the steel material at a temperature of 850 to 1000° C. in a carburizing atmosphere or carbonitriding atmosphere, and step 2: a treatment which quenches the carburized or carbonitrided steel material, by using quenching oil having a temperature of 40 to 80° C. and a kinetic viscosity of 20 to 25 mm2/s at 40° C.
摘要:
The invention relates to a corrosion and wear resistance cold work tool steel. The steel includes the following main components (in wt. %): C 0.3-0.8, N 1.0-2.2, (C+N) 1.3-2.2, C/N 0.17-0.50, Si≦1.0, Mn 0.2-2.0, Cr 13-30, Mo 0.5-3.0, V 2.0-5.0, balance optional elementals, iron and impurities.
摘要:
A method for fabricating crystalline surface structures (4) on a template (1). The method comprises the steps of providing a template (1) into a reaction environment, wherein one or more elements (3) required for the formation of the crystalline surface structure (4) are contained within the template (1); heating the template (1) inside the reaction environment to increase the mobility of the element (3) within the template (1), and to increase the surface diffusion length of the element (3) on the template-environment interface; and activating the template (1) by altering the conditions within the reaction environment, to make the mobile element (3) slowly migrate towards the template-environment interface and to make the element (3) organize on the surface of the template (1) as a crystalline structure (4).
摘要:
The invention relates to a screw having a head, an adjoining retaining section and a functional tip for use as a self-tapping screw. The functional tip is of greater hardness than the retaining section. The entire screw is made of hardened low-alloy carbon steel. The special feature of this screw is that its functional tip has a higher carbon and/or nitrogen content than its retaining section.
摘要:
A gear that is formed of material steel molded to include a disc portion and a plurality of tooth portions circumferentially discretely formed on the disc portion and have a shape in which tooth root portions are formed between the tooth portions, and is subjected to vacuum carburizing treatment and subsequent quenching treatment with high-density energy heating after being molded.
摘要:
A method for improving corrosion resistance and fatigue performance of a metallic surface of an article comprises nitrocarburizing the metallic surface to provide a nitrocarburized surface; forming an oxide layer on the nitrocarburized surface; and treating the oxide layer with a mechanical process.
摘要:
A predetermined steel containing Te: 0.0005 mass % to 0.0050 mass % is heated to 1320° C. or lower to be subjected to hot rolling, and is subjected to annealing, cold rolling, decarburization annealing, and nitridation annealing, and thereby a decarburized nitrided steel sheet is obtained. Further, an annealing separating agent is applied on the surface of the decarburized nitrided steel sheet and finish annealing is performed, and thereby a glass coating film is formed. The N content of the decarburized nitrided steel sheet is set to 0.0150 mass % to 0.0250 mass % and the relationship of 2×[Te]+[N]≦0.0300 mass % is set to be established. Note that [Te] represents the Te content and [N] represents the N content.
摘要:
Disclosed is a steel for machine structural use including 0.05-0.8% of C, 0.03-2% of Si, 0.2-1.8% of Mn, 0.1-0.5% of Al, 0.0005-0.008% of B, and 0.002-0.015% of N, and including 0.03% of P or less (excluding 0%), 0.03% of S or less (excluding 0%), and 0.002% of O or less (excluding 0%), with the remainder comprising iron and unavoidable impurities. The ratio of BN/AlN precipitated in the steel is 0.020-0.2. Also disclosed is a case hardened steel component in which the ratio of BN/AlN deposited on the carburized or carbonitrided component surface is 0.01 or less and a manufacturing method for same. The steel for machine structural use exhibits excellent machinability in continuous cutting at high speeds using cemented carbide tools, and in interrupted cutting at low speeds using high-speed steel tools, as well as excellent impact performance, even after being subjected to a heat treatment such as quenching and tempering. Furthermore, the case hardened steel component exhibits excellent fatigue resistance, and particularly excellent pitting resistance.
摘要:
Hot rolling is performed on a steel with a predetermined composition containing Ti: 0.0020 mass % to 0.010 mass % and/or Cu: 0.010 mass % to 0.50 mass % to obtain a hot-rolled steel sheet. Annealing is performed on the hot-rolled steel sheet to obtain an annealed steel sheet. Cold rolling is performed on the annealed steel sheet to obtain a cold-rolled steel sheet. Decarburization annealing and nitridation annealing are performed on the cold-rolled steel sheet to obtain a decarburized nitrided steel sheet. Then, finish annealing is performed on the decarburized nitrided steel sheet. When obtaining the decarburized nitrided steel sheet, heating on the cold-rolled steel sheet is started in a decarburizing and nitriding atmosphere, then first annealing is performed at a first temperature within a predetermined range, and then second annealing is performed at a second temperature within a predetermined range.