摘要:
There is provided an inexpensive rolling element used under high interface pressure such as induction hardened gears, the rolling element being improved in the seizure resistance of its tooth flanks and having a temper hardness of HRC 50 or more at 300null C. To this end, the rolling element is made from a steel material containing at least 0.45 to 1.5 wt % C and one or more alloy elements selected from 0.1 to 0.5 wt % V and 0.3 to 1.5 wt % Cr, and has a rolling contact surface layer having a structure tempered at low temperature in which 2 to 18% by volume cementite disperses in a martensite parent phase formed by induction heating and cooling and containing 0.25 to 0.8 wt % carbon solid-dissolving therein.
摘要:
The invention concerns a method for the manufacturing of a wire-shaped product with high wear resistance. The characteristic feature is that a melt is prepared of a martensitic stainless chromium steel which contains in weight-% 0.6-3.0 C, max 2.0 Si max 2.0 Mn, 13-30 Cr, 0-10 Mo, from zero to totally max 10% of those strong carbide forming elements which belong to the group of elements which comprises V, Nb, Ta and Zr, totally max 1% of other, optionally existing alloying elements, balance iron and unavoidable impurities, that the melt is tapped and caused to solidify through cooling at a cooling rate of at least 100° C./s so that a solidified material is obtained which contains evenly distributed carbides, wherein essentially all existing carbide particles has a maximal particle size of 8 &mgr;m, particle size being defined as the mean value of the length and breadth of a particle observable in a light-optical microscope, and that an intermediate product is formed of said material in the form of a wire which is cold drawn and optionally is cold-rolled to desired final dimension, whereafter the wire is hardened and tempered for the achievement of said wire-shaped product which has a microstructure substantially consisting of tempered martensite containing carbides with a particle size of max 8 &mgr;m. The invention also concerns the wire-shaped product and its use for wear parts in combustion engines.
摘要:
The present invention provides cast high-carbon steel having high strength and plasticity and a method for its formation. In the method, forming during cooling from the melting point through temperature control results in a structure having small size cementite grains supported in a plastic matrix. Alloys other than high-carbon steel, including nickel, titanium, zirconium, and aluminum, can also be produced by the process.
摘要:
Steel strapping and a method of manufacturing steel strapping are disclosed. The steel strapping has the following composition in wt % and a microstructure including a matrix of recovery-annealed cold worked ferrite containing martensite and carbides dispersed through the matrix. C: up to 0.2 Mn: up to 2.0 Si: 0.2-0.4 Ti: 0.025-0.045 V: 0.05-0.07 Cr: up to 0.25 Ni: up to 0.30 Mo: up to 0.10 N: up to 0.005 Cu: up to 0.20 Al: up to 0.08 Nb: up to 0.005 P: up to 0.035 S: up to 0.020 Balance iron and incidental impurities.
摘要:
Systems and methods monitor the activity of carbon in a heat treating atmosphere, e.g., where a two phase region is desired for spherodize annealing. The systems and methods generate a computed activity of carbon value for the gas atmosphere as a function of temperature, partial pressure of oxygen, and carbon monoxide content of the gas atmosphere, and without determining a carbon dioxide content of the gas atmosphere. The systems and methods can make use of the computed activity of carbon value, e.g., to control the gas atmosphere.
摘要:
A structure of at least a stationary-side race of a bearing is transformed into a lower bainite structure through an isothermal transformation treatment. Furthermore, the adjustment is made for hardness to HRC=54 to 64, an amount of residual austenite to not more than 5% and an area percentage of 0.8 &mgr;m or longer carbide to not more than 20% based on the total area of secondary carbide. Thus is prevented the occurrence of a white layer in the rolling bearing.
摘要:
A high strength steel alloy for use in manufacturing railway car components. The alloy has a chemical composition that meets the industry required specifications for B grade steel and exhibits better mechanical properties, such as higher yield and tensile strengths. Secondary benefits of the inventive steel alloy include enhanced weldability and improved fatigue resistance.
摘要:
A forged roll for rolling a seamless steel pipe, having excellent biting properties and wear resistance, and manufacturing method. The forged roll comprises a high carbon alloy cast steel comprising about 1.10-1.85 wt % carbon, about 0.3-1.2 wt % silicon, about 0.4-1.5 wt % manganese, about 0.5-2.0 wt % nickel, about 0.5-2.0 wt % chromium and iron. Heat treatment for spheroidal carbide formation is performed so that the spheroidal carbide covers about 35-55% of the area of the roll metallurgical structure.
摘要:
High strength steel is produced by a first rolling of a steel composition, reheated above 1100.degree. C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above AR.sub.3 to less than 400.degree. C. and followed by tempering below the Ac.sub.1 transformation point.
摘要:
High strength steel is produced by a first rolling of a steel composition, reheated above 1100.degree. C., above the austenite recrystallization, a second rolling below the austenite recrystallization temperature, water cooling from above Ar.sub.3 to less than 400.degree. C. and followed by tempering below the Ac.sub.1 transformation point.