摘要:
A heat treatment process for through hardening results in high surface compressive stresses. The method includes heating a steel component to a first temperature, quenching the steel component to a second temperature, maintaining the steel component at the second temperature for a first duration of time, heating the steel component to a third temperature, maintaining the steel component at the third temperature for a second duration of time, and quenching the steel component to a fourth temperature when austenite to martensite+bainite or bainite transformation is at least 10% but less than 85% complete.
摘要:
This heat treatment of bearing steel comprises annealing and hardening. Hardening is carried out after annealing and after the manufacture of structural parts from this steel. The first part of the annealing process is heating of the steel at a rate of more than 1 °C/s to a temperature in the range between 750 °C and 900 °C. It is followed by holding at the temperature achieved for at least 400 seconds. This is followed by cooling at a rate higher than 0.02 °C/s to a temperature, at which austenite begins to transform to ferrite and carbides. In the next step, there is cooling to such temperature and at such rate that complete transformation of austenite to ferrite and carbides takes place at least in the desired location of the steel. The cycle of heating, holding and cooling is carried out at least once. Then the steel is cooled to the ambient temperature. In the preferred embodiment, the quenching temperature during subsequent hardening is lower than the quenching temperature of the conventionally annealed steel in question. The steel may be heated by induction.
摘要:
A mainly bainitic steel having the following composition in weight percent: carbon 0.6-1.1; silicon 1.5 to 2.0; manganese 1.8 to 4.0; chromium 1.2 to 1.4; nickel 0-3; molybdenum 0.2 to 0.5; vanadium 0.1 to 0.2, balance iron save for incidental impurities.
摘要:
Disclosed is a temporary and mobile apparatus and methods for manufacturing welded products, including pressure vessels, wherein heating and/or cooling is to be applied to substrate material of the weld site. Certain embodiments include panels arranged to form a convection section that allows for improved heating and cooling of substrates and provide improved welding processes. Embodiments can include a manifold along used for heating and cooling. Apparatuses and methods of using making those apparatuses for improved welding are described herein.
摘要:
Die Erfindung betrifft ein Verfahren zum Herstellen eines Werkzeugstahls für Kaltarbeits- und Warmarbeitsanwendungen, wobei ein Stahlmaterial bestehend aus folgenden Legierungselementen: (alle Angaben in Gew.-%): Kohlenstoff = 1,50 bis 2,50; Silizium = 0,25 bis 1,0; Mn = 0,10 bis 1,0; Cr = 4,0 bis 7; W = 12 bis 16; Mo = 1,0 bis 5,0; V = 3,0 bis 7,0; Co = 6,0 bis 8,0; Rest Eisen und erschmelzungsbedingte unvermeidliche Verunreinigungen erschmolzen und durch Verdüsen zu einem Pulver verarbeitet wird und das Pulver anschließend heiß-isostatisch gepresst oder dreidimensional verdruckt wird und das heiß-isostatische Pulver anschließend gegebenenfalls mechanisch bearbeitet wird, wobei eine Wärmebehandlung folgt, wobei die Wärmebehandlung so durchgeführt wird, dass das Material zunächst auf eine Härtetemperatur von 1170 °C - 1190 °C im Kern erwärmt wird, danach für 60 bis 300 Sekunden bevorzugt 100 bis 200 Sekunden auf dieser Härtetemperatur gehalten und danach mit einer Abkühlrate von λ
摘要:
A method for including a feature in an article manufactured from a maraging stainless steel comprises the steps of focusing an energy beam on the article at a temperature of at least 1000 °C in a nitrogen-free atmosphere. The beam generates intense energy and melts/vaporizes the maraging stainless steel and thus includes the feature along with austenitic edges. The article is cooled to a temperature of between 0 °C and -80 °C, in order to subject the austenitic edges to the isothermal martensitic transformation. The article is finally hardened at a temperature between 375 °C and 600 °C to cause particles in the edges to precipitate out from solution into martensitic structure.
摘要:
Bei einer Wälzlagerung einer zum Antrieb durch einen Hauptantrieb eines Fahrzeugs vorgesehenen Welle eines Nebenaggregats des Fahrzeugs mit wenigstens einer Laufbahnoberfläche für Wälzkörper der Wälzlagerung ist wenigstens eine Schicht unmittelbar unter der Laufbahnoberfläche mit einem bainitischen Gefüge ausgebildet.
摘要:
The invention relates to a method for producing a shaft (10) comprising a first section, a second channelled section, and a third section (T3) provided with an abutment shoulder surface (22) for the starter, said method comprising the following steps: a) said three sections are machined; b) external grooves are produced in the second section; and c) at least one axial part of the starter shaft (10) is subjected to a surface heating treatment. The invention is characterised in that the method comprises an additional step, prior to the heating treatment step, for reducing the residual mechanical stresses resulting from steps preceding the heating treatment. Said additional step is a step for annealing, especially by induction heating, at least one axial part (18-22, T3) of the starter (10).
摘要:
An apparatus (10) for subjecting articles of manufacture to a cryogenic thermal cycling process includes a bottom portion (11) and a lid (28). The bottom portion (11) comprises an outer and inner tank (12 and 14) respectively separated by a plurality of insulation layers. The inner tank (14) defines an inner cavity (29) wherein the articles are subjected to the cryogenic process. A thermal break is provided between the lid (28) and bottom portion (11) so that the temperature of the inner cavity (29) does not conduct to the outer tank (12) of the apparatus bottom portion (11). The process conducted in the apparatus (10) is controlled by a pre-progammed profile inputted by a key controller (124) or PC. Liquid nitrogen is the preferred cryogenic material to be employed. The novel process subjects the article to extreme negative temperatures for a number of cycles. The process is completed by heating the article to an extreme positive temperature and then allowed to cool to ambient room temperature. The novel cryogenic thermal cycling process strengthens the article by realigning its molecular structure to eliminate micro-cracking and other manufacturing deforming characteristics.