摘要:
A surface of a steel, as a material for a crankshaft, is nitrocarburized. The steel contains, as alloy elements C having a content 0.10 mass % or more 0.30 mass % or less, Si having a content 0.5 mass % or more and 0.3 mass % or less, Mn having a content 0.3 mass % or more and 1.5 mass % or less, Mo having a content 0.8 mass % or more and 2.0 mass % or less, Cr having a content 0.1 mass % or more and 1.0 mass % or less, and V having a content 0.1 mass % or more and 0.5 mass % or less, with a remainder consisting of Fe and inevitable impurities. The contents of the alloy elements fall within ranges: 2.0 mass %≦Mn+Cr+Mo≦3.0 mass %, 2.3 mass %≦C+Mo+5V ≦3.7 mass %, and 2.7 mass %≦2.16 Cr+Mo+2.54V≦4.0 mass %. If a steel sample extracted from a central portion of the nitrocarburized steel free from an influence of the nitrocarburizing treatment is austenitized at 1200° C. for one hour, and cooled to a room temperature so that a cooling rate at which the steel sample passes through a temperature range between 900° C. and 300° C. is 0.5° C./second, then an area percentage of a bainite structure in steel structures is 80% or more and a Vickers hardness measured at a cross section is 260 Hv or more and 330 Hv or less. A surface hardness of a nitrocarburized layer is 650 Hv or more, a formation depth of the nitrocarburized layer is 0.3 mm or more, and a hardness of the central portion is 340 Hv or more. Thereby a crankshaft which is excellent both in the machinability and in fatigue strength, even after nitrocarburizing treatment on the surface, is provided.
摘要翻译:作为曲轴的材料的钢的表面被氮碳共渗。 钢含有含量为0.10质量%以上且0.30质量%以下的合金成分C,含有0.5质量%以上且0.3质量%以下的Si,含有0.3质量%以上且1.5质量%的Mn %以下,含量为0.8质量%以上且2.0质量%以下的Mo为0.1质量%以上且1.0质量%以下的Cr,含量为0.1质量%以上至0.5质量%的V以下, 或更少,余量由Fe和不可避免的杂质组成。 合金元素含量在2.0质量%<= Mn + Cr + Mo <= 3.0质量%,2.3质量%<= C + Mo + 5V≤3.3质量%,2.7质量%<= 2.16Cr的范围内 + Mo + 2.54V <= 4.0质量%。 如果不受氮碳共渗处理的影响,从氮碳共渗钢的中央部提取的钢样品在1200℃下奥氏体化1小时,冷却至室温,钢样品通过的冷却速度 在900℃至300℃之间的温度范围为0.5℃/秒,则钢结构中贝氏体组织的面积百分比为80%以上,横截面测得的维氏硬度为260Hv或 多达330 Hv以下。 氮碳共渗层的表面硬度为650Hv以上,氮覆层的形成深度为0.3mm以上,中央部的硬度为340Hv以上。 因此,即使在表面进行氮碳共渗处理之后,也提供了在机械加工性和疲劳强度方面优异的曲轴。
摘要:
Steel and steel shaped articles with an excellent delayed fracture resistance and a tensile strength of the 1600 MPa class or more, containing, by mass %, C: 0.20 to 0.60%, Si: 0.50% or less, Mn: over 0.10% to 3%, Al: 0.005 to 0.1%, Mo: over 3.0% to 10%, and, as needed, one or more of W: 0.01 to 10%, V: 0.05 to 1%, Ti: 0.01 to 1%, Nb: 0.01 to 1%, Cr: 0.10 to 2%, Ni: 0.05 to 1%, Cu: 0.05 to 0.5%, and B: 0.0003 to 0.01%, and a balance of Fe and unavoidable impurities and, further, a method of production comprising shaping the above steel to a desired shape (for example, a bolt shape), quenching it, then tempering it at 500 to 750° C. in temperature range.
摘要:
Steel and steel shaped articles with an excellent delayed fracture resistance and a tensile strength of the 1600 MPa class or more, containing, by mass %, C: 0.20 to 0.60%, Si: 0.50% or less, Mn: over 0.10% to 3%, Al: 0.005 to 0.1%, Mo: over 3.0% to 10%, and, as needed, one or more of W: 0.01 to 10%, V: 0.05 to 1%, Ti: 0.01 to 1%, Nb: 0.01 to 1%, Cr: 0.10 to 2%, Ni: 0.05 to 1%, Cu: 0.05 to 0.5%, and B: 0.0003 to 0.01%, and a balance of Fe and unavoidable impurities and, further, a method of production comprising shaping the above steel to a desired shape (for example, a bolt shape), quenching it, then tempering it at 500 to 750° C. in temperature range.
摘要:
The present invention provides a high strength bolt excellent in delayed fracture resistance able to advantageously prevent hydrogen embrittlement as represented by the delayed fracture phenomenon occurring along with an increase in strength and causing a particular problem, and a method of production of the same, containing, by mass %, C: 0.2 to 0.6%, Si: 0.05 to 0.5%, Mn: 0.1 to 2%, Mo: 0.5 to 6%, and Al: 0.005 to 0.5%, having a tensile strength of 1400 MPa or more, and having a compressive residual stress of the surface layer of the thread root of 10 to 90% of the tensile strength. Further, a surface layer part of the thread root from the surface down to at least 50 μm has pre-austenite grains with an aspect ratio of the axial direction and radial direction of 2 or more and that part has a hardness of Hv 460 or more. Further, the method of production comprises using the steel material having the above ingredients to shape the bolt head and shaft, then heat the bolt to 900 to 1100° C., quench it, temper it by a 580° C. or higher temperature, then thread roll it.
摘要:
The present invention provides a high strength bolt excellent in delayed fracture resistance able to advantageously prevent hydrogen embrittlement as represented by the delayed fracture phenomenon occurring along with an increase in strength and causing a particular problem, and a method of production of the same, containing, by mass %, C: 0.2 to 0.6%, Si: 0.05 to 0.5%, Mn: 0.1 to 2%, Mo: 0.5 to 6%, and Al: 0.005 to 0.5%, having a tensile strength of 1400 MPa or more, and having a compressive residual stress of the surface layer of the thread root of 10 to 90% of the tensile strength. Further, a surface layer part of the thread root from the surface down to at least 50 μm has pre-austenite grains with an aspect ratio of the axial direction and radial direction of 2 or more and that part has a hardness of Hv 460 or more. Further, the method of production comprises using the steel material having the above ingredients to shape the bolt head and shaft, then heat the bolt to 900 to 1100° C., quench it, temper it by a 580° C. or higher temperature, then thread roll it.
摘要:
An etching method for a silicon substrate, which can easily smooth the etching surface of the (110)-oriented silicon, is disclosed. A container is filled with KOH solution. In the KOH solution is immersed a (110)-oriented silicon wafer having a PN junction and is also disposed a platinum electrode plate to face the silicon wafer. To between a platinum electrode of the silicon wafer and the platinum electrode plate are connected a constant voltage power source, an ammeter and a contact in series. A controller starts etching from one surface on which the PN junction is formed, and terminates voltage application when the specified time lapses after the formation of an anodic oxide film is equilibrated with the etching of the anodic oxide film on the etching surface on the PN junction part. In this case, the controller detects flowing current through the ammeter, and the point of time when the equilibrium state is obtained is the point of inflection of the detected current to the constant current after the peak thereof.
摘要:
A method of manufacturing a sheave member for a belt-type continuously variable transmission includes a forming step wherein an intermediate product having a sheave surface is formed by forging a steel material; a carburization step wherein the intermediate product is heated in a carburization gas; a gradual cooling step wherein the cooling speed is equal to or less than 20° C./sec, at least until the temperature of the intermediate product has passed through the transformation point; a high-frequency electrical heating step wherein a selected portion(s) of the intermediate product is heated; a water quenching step wherein the selected portion is quenched by contact with water; and a finishing step wherein a grinding process is applied to the intermediate product to attain the final shape. In the cooling step, preferably, the intermediate product is contacted with a cooling gas at a pressure lower than atmospheric pressure.
摘要:
The present invention provides case-hardening steel superior in tooth surface fatigue strength and a gear using the same used for parts of automobiles, construction machines, industrial machines, etc., that is case-hardening steel superior in tooth surface fatigue strength containing, by wt %, C: 0.1 to 0.3%, Si: 1.0 to 2.0%, Mn: 0.3 to 2.0%, S: 0.005 to 0.05%, Cr: 1.0 to 2.6%, Mo: 0.8 to 4.0%, V: 0.1 to 0.3%, Al: 0.001 to 0.2%, and N: 0.003 to 0.03%, limiting P to 0.03% or less, and having as a balance iron and unavoidable impurities, and satisfies the following expression, 31Si (%)+15Mn (%)+23Cr (%)+26Mo (%)+100V (%) is 100 or more, and a gear comprised of case-hardening steel and having an X-ray diffraction half width at a depth of 50 mm from the surface of the gear of 6.4 degrees or more.
摘要:
This invention aims to provide a carburized component realizing a larger strength for power transmission components such as gears, and a method of manufacturing the same. The carburized component of this invention, aimed at realizing the object, consists essentially of, in % by mass and both ends inclusive, C: 0.1-0.30%, Si: 0.80-1.50%, Mn: 0.30-1.20%, Cr: 2.0-5.5%, and the balance of Fe and inevitable impurities; has a mean C concentration over the range from the surface of the steel to a depth of 0.2 mm after vacuum carburization of 1.2% or more and 3.0% or less, and has a ratio of a carbide area over the range from the surface to a depth of 50 μm of 15% or more and 60% or less, has the carbide precipitated in a finely dispersed manner so that the carbide having a grain size of 10 μm or less accounts for 90% or more of the entire portion, and has a depth of a grain boundary oxide layer below the surface of 1 μm or less.
摘要:
A sunlight sensor is provided which detects sunlight by means of a semiconductor device and achieves the desired elevation angle characteristics. The sunlight sensor is implemented as a semiconductor device having p+ layers 10 and 11 as a light-responsive section and an n+ or n layer 9 as a light-nonresponsive section, and additionally having a light-detection element 2 which outputs a detection signal responsive to the amount of light received by the p+ layers 10 and 11. A light-transparent molding 4 is provided at least over the light-detection element 2, and additionally a light-cutoff mask 5 is provided on the transparent molding 4. The relative positions of the light-cutoff mask, the p+ layers 10 and 11, and the n+ or n layer 9 are then established. By doing this, of the shadow of the light-cutoff mask 5 which is created when incident sunlight 13 and 14 strikes the light-detection element, the surface area of at least the part of the shadow which falls on the p+ layers 10 and 11 and the part of the shadow that falls on the n+ or n layer 9 are controlled so as to obtain the desired elevation angle characteristics.