30 results about "Compacted graphite iron" patented technology

The present invention relates to a coated cemented carbide milling insert for either wet or dry machining of cast iron such as nodular cast iron (NCI), grey cast iron (GCI), austempered ductile iron (ADI) and compacted graphite iron (CGI) where a high wear resistance and an excellent resistance against thermo cracks are required comprising:a substrate comprising from about 5 to about 7 wt-% Co, from about 140 to about 250 ppm Ti+Ta and balance WC with a weight ratio Ti / Ta of from about 0.8 to about 1.3 anda PVD-layer consisting of AlxTi1−xN, with x=from about 0.50 to about 0.70 and with a thickness of from about 1 to about 10 μm. The invention also relates to a method for making cutting tool inserts and their use.

The present invention relates to cast iron, and more specifically relates to CGI (Compacted Graphite Iron) cast iron in which the amounts of carbon (C), silicon (Si), manganese (Mn), copper (Cu), tin (Sn) and magnesium (Mg) are controlled during production, thereby improving the castability and also giving a stable tensile strength and yield strength and giving an appropriate range of hardness, and also to a production method for the same.

A method of analysing an iron melt for producing compacted graphite iron, comprising the steps of: receiving thermal data from cooling of a cast melt comprising a predetermined amount of carbon, magnesium, balance iron and unavoidable impurities, plotting the temperature of the cast melt against time such that a plotted time-temperature curve is generated, comparing the generated plotted curve to at least one reference curve, said reference curve representing a corresponding thermal analysis of another melt, the resulting nodularity of which is known, for the purpose of predicting the nodularity of the cast melt on basis of the difference between said curves. The comparison on which the nodularity is predicted is performed along each of said curves for a time interval t1-t2 corresponding to a temperature interval T1-T2, where T1 is in the range of TEstart - TEmim where TEstart is the temperature of beginning formation of graphite in the melt and TEmin is a minimum temperature before start of eutectic recalescence in the melt, and T2 is in the range of Tsolidus-(Tsolidus-20oC), and other time intervals in said curves are excluded from said comparison.

A process for production of compacted graphite iron using in-mould addition of a magnesium alloy is disclosed. The process is characterised by a step of pre-treating the base iron in a ladle or in a furnace with an alloy containing cerium and performing a structure forming treatment in a reaction chamber in the mould using an alloy containing magnesium and lanthanum.

The invention discloses solution strengthening ferrite vermicular graphite cast iron and a production method thereof. The matrix structure of the solution strengthening ferrite vermicular graphite cast iron comprises ferrite with the mass percentage larger than 80%, and the ferrite is subjected to solution strengthening through Si. The components of the solution strengthening ferrite vermicular graphite cast iron include, by mass, 2.9-3.5% of C, 3.0-4.8% of Si, 0.0001-0.3% of Mn, 0.0001-0.07% of P, 0.0001-0.2% of Cu, 0.0001-0.1% of Cr, 0.0001-0.1% of Mo, 0.0001-0.02% of Sn, 0.007-0.020% of S, 0.008-0.030% of Mg, 0.010-0.040% of RE and the balance Fe and inevitable microelements, wherein the carbon equivalent needs to be kept at 4.2-4.6% and is equal to the mass percentage of carbon plus one third the mass percentage of silicon. The production method of the solution strengthening ferrite vermicular graphite cast iron comprises the steps of blending and melting, vermicularizing and inoculation treatment and cooling and unpacking. By adoption of the solution strengthening ferrite vermicular graphite cast iron and the production method thereof, the mechanical performance and machining performance of the vermicular graphite cast iron are effectively improved, and meanwhile, the production cost of the vermicular graphite cast iron is reduced.

The invention discloses a vermicular graphite cast iron piston ring for an internal combustion engine. The vermicular graphite cast iron piston ring comprises a piston ring body, wherein anti-adherent films cover the upper surface, the lower surface, and one surface, facing a position ring groove, of the piston ring body; an abrasion-resistant layer is arranged on the other surface, in contact with a cylinder, of the piston ring body; the abrasion-resistant layer extends along the other surface, in contact with the cylinder, of the piston ring body, to form a first tongue part and a second tongue part; a bulged circular barrel shape is formed on the outer circumferential surface of the first tongue part, and an opening part is formed in the other surface, in contact with the cylinder, of the piston ring body; a bulged circular barrel shape is formed on the outer circumferential surface of the second tongue part, and an opening part is formed in the other surface, in contact with the cylinder, of the piston ring body. The piston ring can remain the adhering preventing effect for a long term under high temperature, so that the problem of non-uniform abrasion of the contact surface of the inner circumferential surface of the cylinder can be solved, and as a result, the comprehensive performance of the piston ring body can be improved, and the piston ring is durable.

The invention discloses high-magnesium and low-rare-earth austenite vermicular graphite cast iron and a preparation method and application thereof, and belongs to the field of cast iron. The high-magnesium and low-rare-earth austenite vermicular graphite cast iron comprises the following chemical constituents including 2.0%-3.8% of carbon, 1.5%-3.0% of silicon, 0.8%-2% of manganese, 7%-18% of nickel, 3%-8% of copper, 0.05%-2.7% of chromium, 0.08%-0.12% of magnesium, not larger than 0.03% of rare earth, 0.1%-0.18% of titanium, not larger than 0.08% of sulfur, not larger than 0.15% of phosphorusand the balance iron and inevitable impurities. The structure of the cast iron is an austenite matrix, vermicular graphite and a quite small amount of spheroidal graphite. Through adjustment on the contents of magnesium, titanium, rare earth and manganese and the process, the vermicularity rate of the obtained cast iron is larger than or equal to 91%, the tensile strength exceeds 360 MPa, the coefficient of linear expansion reaches 18.9*10<-6>, extremely good tensile strength and wear resistance are obtained, and unexpected effects are gained.

The invention relates to an alloy vermicular cast iron for a railway vehicle brake disc and a melting method thereof. The chemical composition of the vermicular cast iron, in terms of mass percentage, includes: C: 3.3-3.5%, Si: 2.3-2.5%, Mn: 0.4~0.7%, Cu: 0.6~1.0%, Mo: 0.2~0.6%, Ni: 0.6~1.0%, P≤0.07%, S≤0.02%, and the balance of Fe, among them, vermicular graphite cast iron brake disc The creep rate is ≥75%, and the pearlite content is 50%-60%. The invention can increase the stress threshold value of disc cracking and expansion caused by thermal stress concentration, and improve the mechanical properties of the railway vehicle brake disc.

A method of inoculating magnesium (Mg) on compacted graphite iron (CGI) comprises: providing a partition having a predetermined height on the bottom of a ladle so as to divide the interior of the ladle into a first space and a second space; laminating an Mg inoculant and a cover in order in the second space; and tapping liquid CGI cast iron onto the first space, whereby the Mg inoculant becomes in contact with the liquid CGI iron after the liquid CGI tapped onto the first space goes over the partition toward the second space and after the cover is melted by the liquid CGI. According to the method, the deviation of density of Mg is minimized, and a secondary inoculating process can thus be omitted.

The invention relates to a single cylinder diesel engine body and particularly relates to a vermicular graphite cast iron single cylinder diesel engine body with high vermicular graphite rate. The single cylinder diesel engine body comprises the following chemical components in percentage by mass: 3.5-3.8% of C, 2.1-2.6% of Si, 0.5-0.8% of Mn, less than 0.08% of P, less than 0.03% of S and the balance of iron and inevitable impurities. The single cylinder diesel engine body provided by the invention has the characteristics of less inclination of shrinkage cavity and shrinkage porosity and long service life. The invention further provides a preparation method of the single cylinder diesel engine body, which is reasonable in process.

Provided is a production process of forced air cooling whole-sorbite type vermicular graphite cast iron. Vermicular graphite cast iron workpieces are contained in a stainless steel protecting box, thestainless steel protecting box is filed with particulate charcoal, and then the stainless steel protecting box is placed into a box type electric furnace heated to be 900 DEG C, and is subjected to constant temperature for 2 hours under the set austenitizing temperature; the vermicular graphite cast iron workpiece subjected to diathermanous treatment for regulated time are fast taken out of the protecting box in the box type furnace, and sequentially hung on a hanging frame in front of the furnace; two draught fans are started to be aligned with the direction of the vermicular graphite cast iron workpieces for opposite blowing, and the cooling speed of vermicular graphite cast iron test rods is controlled to be larger than or equal to 100 DEG C / min; and when the temperature of the vermicular graphite cast iron workpieces subjected to air cooling is 490-500 DEG C, air blowing stops, and after air cooling continues to be performed till room temperature is achieved, and the whole-sorbitetype vermicular graphite cast iron workpieces are obtained. The production process of the forced air cooling whole-sorbite type vermicular graphite cast iron has the beneficial effect of being simplein process, after high-temperature heating forced air cooling heat treatment, a novel vermicular graphite cast iron material with higher mechanical performance is obtained, and the strength, hardnessand the abrasion resistance indexes of the novel vermicular graphite cast iron material should approach or reach more than two times those of the common as-cast vermicular iron.

The present invention discloses coated milling inserts particularly useful for milling of compacted graphite iron under wet conditions at moderate cutting speeds comprising a cemented carbide body and a coating. The cemented carbide body comprises WC, 7.3-7.9 wt-% Co and 1.0-1.8 wt-% cubic carbides of Ta and Nb and a highly W-alloyed binder phase. The radius of the uncoated cutting edge is 25-45 µm. The coating comprises - a first <1 µm TiC x N y O z layer adjacent to the cemented carbide having a composition of x+y=1, x>= 0, - a second 1-2 µm TiC x N y O z layer having a composition of x>0.4, y>0.4 and 0=<z<0.1 - a third <1 µm TiC x N y O z layer having a composition of x+y+z>=1 and z>0 - an ±-Al 2 O 3 -layer with a thickness of 2.1-3.3 µm and - a further 0.1-2.5 µm, thick layer of TiN missing along the edge line.

Method for determining the cuttability of a compact graphite iron, characterised by the steps of: - arriving at a relationship between cuttability and contents of carbide-stabilising substances in compact graphite iron, which relationship is arrived at empirically from measured cuttability and measured contents of carbide-stabilising substances in a plurality of test pieces of compact graphite iron; - providing a compact graphite iron; - determining the contents of carbide-stabilising substances in the compact graphite iron provided; - determining a value for the cuttability of the compact graphite iron provided on the basis of the relationship and contents of carbide-stabilising substances in the compact graphite iron provided.

The invention discloses a low-tin-silicon-molybdenum vermicular graphite cast iron. The low-tin-silicon-molybdenum vermicular graphite cast iron consists of the following components by weight percentage: 3.4-3.8% of carbon, 2.1-2.6% of silicon, and 0.1-2.6% of molybdenum 0.3%, manganese 0.2‑0.3%, niobium 0.2‑0.3%, chromium 0.1‑0.2%, tin 0.01‑0.03%, antimony 0.01‑028%, vanadium 0.1‑0.18%, titanium 0.15‑0.25 %, the total content of phosphorus and sulfur does not exceed 0.06%, and the balance is iron and its unavoidable impurities. The low-tin-silicon-molybdenum vermicular graphite cast iron of the present invention has a small whiting tendency and a small length-thickness ratio of the vermicular graphite, so that the low-tin-silicon-molybdenum vermicular graphite cast iron has excellent strength, wear resistance and thermal fatigue resistance. At the same time, the present invention also provides a method for preparing the above-mentioned low-tin-silicon-molybdenum vermicular graphite cast iron, so that the obtained low-tin-silicon-molybdenum vermicular graphite cast iron has high creep rate, good comprehensive performance, simple process operation, and is suitable for large-scale industrial production.