8 results about "Volume fraction" patented technology

A steel sheet has a predetermined chemical composition, in which a metallographic structure in a surface layer region ranging from a surface to a position of 20 μm from the surface in a sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 0.01% to 5.0%, a metallographic structure in an internal region ranging from a position of more than 20 μm from the surface in the sheet thickness direction to a ¼thickness position from the surface in the sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 2.0% to 10.0%, the volume fraction of the secondary phase in the surface layer region is less than the volume fraction of the secondary phase in the internal region, and in the surface layer region, an average grain size of the secondary phase is 0.01 μm to 4.0 μm, and a texture in which an XODF{001} / {111} as the ratio of the intensity of {001} orientation to an intensity of {111} orientation in the ferrite is 0.60 or more and less than 2.00 is included.

The cold-rolled steel sheet has a prescribed chemical composition, and has a microstructure containing, by volume fraction, 95% or more of martensite and 95% or less of tempered martensite at a t / 4 position where t is the sheet thickness in mm and t is the range of t / 8 position to-3 t / 8 position from the surface in the sheet thickness direction, and a prior austenite particle size of 7.0 [mu] m or less. And the grain boundary segregation degree of Mn is 2.0 or less.

To provide a stainless steel material that has excellent overall corrosion resistance and pitting corrosion resistance in supercritical corrosion environments, and excellent low-temperature toughness in cryogenic environments. [Solution] The stainless steel material according to this disclosure has the chemical composition described in the specification, satisfies formula (1), has a yield strength of 758 MPa or less, and its microstructure consists of retained austenite of 5-30% by volume, ferrite of 0-5.0%, and the remainder being martensite, and the elemental content, yield strength, and volume fraction of the microstructure satisfy formula (2). 0.10 ≤ Cu + W ≤ 2.20 (1) 0.01YS×(Ni+12Co) / (Vγ+3.3Vα′)≧0.0036 (2) In equations (1) and (2), the elemental symbols are substituted with the content of the corresponding element in units of mass%, in equation (2), YS is substituted with the yield strength in units of MPa, Vγ is substituted with the volume fraction of retained austenite, and Vα′ is substituted with the volume fraction of martensite in units of %.

A high-strength hot rolled steel sheet has a chemical composition containing, in % by mass, C: 0.04 to 0.18%, Si: 0.1 to 3.0%, Mn: 0.5 to 3.5%, P: more than 0% and 0.050% or less, S: more than 0% and 0.010% or less, Al: more than 0% and 1.5% or less, N: more than 0% and 0.010% or less, O: more than 0% and 0.003% or less, and Nb: 0.020 to 0.100%, with the balance being Fe and incidental impurities. The steel sheet has a steel microstructure in which bainite is a main phase and in which the volume fraction of retained austenite is less than 3%. (The amount of solute Nb / the total amount of Nb) is 0.300 or more and less than 0.800, and the amount of Nb present as precipitates having a diameter of 100 nm or more is 0.010 to 0.030% by mass.

This invention discloses a method for detecting the volume fraction of W-containing Laves phase in a sample, belonging to the field of metallic material testing technology. This invention provides a method for intuitively detecting the volume fraction of W-containing Laves phase in steel. The laser-clad sample containing the W-containing Laves phase undergoes surface pretreatment to remove surface oxide scale and processing burrs. Ultrasonic cleaning thoroughly removes residual oil, wear debris, and other impurities from the sample surface. High-temperature heat treatment makes the previously difficult-to-distinguish W-containing Laves phase clearly visible. Fine processing of the detection surface ensures a smooth and flat surface, providing a clear observation interface for microscopic morphology observation and compositional analysis. After sample characterization, EDS energy dispersive spectroscopy is used to obtain elemental distribution characteristics. Quantitative calculations are performed on the unoxidized areas of the sample to obtain the volume fraction of the W-containing Laves phase. This provides important data support for material composition design, heat treatment process optimization, service life assessment, failure analysis, and mechanism analysis.

The present invention discloses an R-T-B type neodymium iron boron magnet and a preparation method thereof. By mass ratio of 100%, the magnet comprises the following components: 27.0 - 35.0 wt% of R, where R is at least one rare earth element including Nd; 0.80 - 0.93 wt% of B; 0.1 - 0.50 wt% of Cu; 0.2 - 0.5 wt% of Ga; 0 - 0.5 wt% of M, where M is at least one of Zr and Ti, and the sum of the contents of Cu, Ga and M is greater than 0.9 times the content of B; 0.1 - 1.5 wt% of Al; the balance is Fe, Co and inevitable impurities, and Fe accounts for more than 95 wt% of the total content of Fe, Co and impurities. In this application, by adjusting the proportions of the elements of R, Cu, Ga and M, and the sum of the contents of Cu, Ga and M is greater than 0.9 times the content of B, before the alloy cast sheet is made into powder, the alloy cast sheet is subjected to heat preservation treatment at 750 ± 50 °C, which can, on the premise of ensuring 90 vol% of the main phase, form an R-Ga-Cu-M phase with a volume fraction of more than 40 vol% at the grain boundaries of the magnet, and at the same time, to a certain extent, reduce the existence of the R-T-Ga phase, avoiding the reduction of Hcj of the magnet due to the excessive R-T-Ga phase.

This hot-stamping formed body includes, as a chemical composition, by mass %: C: 0.15% or more and 0.50% or less; Si: 0.10% or more and 3.00% or less; Mn: 0.10% or more and 3.00% or less; P: less than 0.10%; S: less than 0.10%; N: less than 0.10%; Ti: 0.020% or more and 0.150% or less; B: 0.002% or more and 0.010% or less; optionally Al, Cr, Mo, Co, Ni, Cu, V, W, Ca, Mg, and REM; and a remainder including Fe and impurities, in which a microstructure of the hot-stamping formed body includes, by volume fraction, 85% or more of martensite and less than 15% of retained austenite, and in the microstructure, a standard deviation of a frequency distribution of nanohardnesses is 0.70 GPa or less, and an average grain size is 4.0 μm or less.

The invention discloses a metamorphic rock brittleness index determination method and device, equipment and a medium. The method comprises the following steps: determining rock types contained in a rock sample to be measured by utilizing a preset logging curve, and obtaining lithologic mineral components and volume fractions corresponding to each rock type; establishing a rock physical model by using the lithologic mineral composition and the volume fraction; the Young modulus and the cedar ratio of the rock sample to be measured are determined through the rock physical model, and then the brittleness index of the target rock stratum is determined through the Young modulus and the cedar ratio. Through the technical scheme provided by the invention, the rock physical model based on the lithologic mineral cost and the volume fraction can be directly established, and the relationship among the logging time difference curve, the density curve and the rock brittleness is established, so that the brittleness index of the metamorphic rock buried hill is obtained, and the detection accuracy of the metamorphic rock buried hill is improved. The method has the advantages that the required data is less, the data admission cost is saved, and the calculation accuracy is higher.