32results about How to "Increase the number of graphite balls" patented technology

The invention relates to a nodulizing agent partner used for producing nodular cast iron. When the nodulizing agent partner used for producing nodular cast iron is used together with the nodulizing agent, decaying spheroidisation time of molten iron can be delayed, the nodulizing level of nodular iron casting is improved and stabilized, and the number of graphite nodules in the nodular iron is increased. The nodulizing agent partner used for producing nodular cast iron comprises the following elements in parts by weight: 11-13 parts of Ba, 6-11 parts of Bi, 0-10 parts of Sb, 13-15 parts of La, 7-9 parts of Ce, 40-44 parts of Si and 9-15 parts of Fe.

The invention discloses pipe powder for nodular cast iron. The formula of the pipe powder comprises the following components in percentage by weight: 62-70% of Si, 3-10% of Ba, 1-2% of Ca, 0.8-1.8% of Al, 0.5-1.5% of Fe3O4, the balance of Fe and inevitable microelements. According to the pipe powder for the nodular cast iron disclosed by the invention, the overall performance of the nodular cast iron can be improved, and the inoculation efficiency is improved.

The invention discloses a control method for increasing the number of graphite nodules by solid solution strengthening ferrite nodular cast iron with a thick and large cross section, which comprises the following steps: selecting materials: 50-70 percent of pig iron and 30-50 percent of scrap steel; smelting: adding the materials into an electric furnace for smelting, wherein the tapping temperature of the molten iron is 1420-1450 DEG C; spheroidizing: adding a spheroidizing agent, adding a covering agent on the spheroidizing agent, and then spheroidizing, wherein the spheroidizing temperatureis 1420-1450 DEG C; inoculating: adding a silicon-aluminum-calcium-barium type inoculant during a primary inoculation, and respectively adding the inoculant on the surface of the covering agent and the other side of a ladle dam before tapping, wherein the distribution proportion is 50 percent; adding a trace amount of alloy Sb along with the flow of the molten iron during casting, wherein the adding amount of the alloy Sb is 0.003-0.005% of the total amount of the molten iron, molding, casting and cooling: ensuring that the casting opening temperature is controlled to be <= 300 DEG C, and thecasting is obtained by air cooling after the casting is opened. The control method has the advantages of obtaining higher number of the graphite nodules, ensuring a metallographic structure and goodconsistency of performance indexes, thereby improving the quality of the castings and prolonging the service life.

The invention discloses pipe die powder for centrifugally casting a nodular cast iron pipe and a preparation process thereof. The pipe die powder comprises the following components in percent by mass: 60-65 percent of Si, 1.5-2.0 percent of Ca, 2.0-3.0 percent of Ba, 1.4-1.6 percent of Mn, 1.0-1.5 percent of Mg, 1.0-2.0 percent of Zr, 0.7-1.5 percent of Al and the balance of Fe; and the granularities of pipe die powder comprise less than 1.5 percent of 80 mu, 25-30 percent of 100-120 mu, 40-50 percent of 140-180 mu, 25-30 percent of 200-300 mu and less than 2.5 percent of more than 300 mu. The preparation process comprises the following steps of: preparing, melting, pouring, cooling, crushing, milling, proportioning granularities and packaging in vacuum. The pipe die powder has the advantages of uniform components, consistent melting points and reasonable granulometric class, and is beneficial to the prolonging of the service life of a pipe die of the nodular cast iron pipe, the reduction of a series of casting defects of cockles, poor nodulizing, surface cracks and the like of the nodular cast iron pipe, the improvement of the quality of the nodular cast iron pipe and the yield, and the lowering of the production cost.

The invention discloses high-strength nodular cast iron QT900-6 which consists of the following elements in percentage by weight: 3.2-3.7% of C, 2.4-2.8% of Si, less than or equal to 0.2% of Mn, less than or equal to 0.03% of P, 0.005-0.02% of S, 0.8-1.4% of Cu and the balance of Fe and unavoidable trace elements. The high-strength nodular cast iron QT900-6 has high compressive strength, high yield strength and excellent mechanical property.

The invention discloses a carbide-containing ausferrite spheroidal graphite cast iron grinding ball and a manufacturing method thereof, relating to a cast iron alloy containing spheroidal graphite. The grinding ball comprises the following chemical elements in percentage by mass: 3.3 to 3.7 percent of C, 2.4 to 3.3 percent of Si, 2.5 to 3.6 percent of Mn, 0.6 to 1.5 percent of Cr, less than 0.08 percent of P, less than 0.025 percent of S, 0.03 to 0.05 percent of Mg, 0.02 to 0.04 percent of Re and the balance of Fe. The preparation method of the grinding ball comprises the following steps of: (1) raw material preparation and smelting; (2) spheroidization and inoculation; and (3) isothermal quenching heat treatment. In the invention, a certain quantity of carbides and graphite balls are formed in a grinding ball casting-state structure by utilizing a sand lined metal casting technology; and an ausferrite base body with excellent comprehensive mechanical property is obtained by adopting an isothermal quenching technology; and as a certain quantity of carbides are distributed in the ausferrite base body, the carbide-containing ausferrite spheroidal graphite cast iron grinding ball has high wear resistance and toughness.

The invention discloses a production process of a QT500-12 spheroidal graphite iron casting. The production process comprises the following steps: A, raw material selection: selecting 60-80 parts of scrap steel, 20-40 parts of scrap returns, 2.5-3.5 parts of a carburant, 0.4-1.0 part of 75# ferrosilicon, 0.3-0.6 part of copper, 1-1.2 parts of a spheroidizing agent, 0.8-1.2 parts of a 75# ferrosilicon inoculant and 0.2-0.4 part of a silicon-strontium inoculant; B, weighing; C, smelting; D, spheroidizing; E, secondary inoculation; and F, pouring. The overall performances of the QT500-12 spheroidal graphite iron casting produced by using the production process are improved, and the tensile strength is larger than or equal to 500Mpa on the premise that the elongation percentage is larger than or equal to 12%; the consistency of a matrix structure of the spheroidal graphite iron casting is also realized, and the local function of the spheroidal graphite iron casting is prevented from being deteriorated; and the weight of the spheroidal graphite iron casting is reduced on the premise that the elongation percentage and tensile strength indexes of the spheroidal graphite iron casting reach standards, so that the lightweight of the spheroidal graphite iron casting is realized.

The invention relates to a method for preparing a megawatt wind power high-strength high-toughness and low-temperature spheroidal iron casting. The method comprises the following steps of: smelting cast iron serving as a raw material, wherein the smelting temperature is between 1,400 and 1,450 DEG C; spheroidizing, inoculating and recarburizing the raw material, wherein the spheroidizing temperature and the inoculating temperature are between 1,350 and 1,400 DEG C; and casting the obtained product to obtain the low-temperature Ni-free spheroidal iron casting. The formula of the spheroidal iron casting comprises the following components: 3.6 to 3.9 wt percent of C, 1.7 to 2.3 wt percent of Si, 0.1 to 0.3 wt percent of Mn, 0.01 to 0.06 wt percent of Sn, and 0.03 to 0.07 wt percent of residual Mg content. The components of high-strength high-toughness and low-temperature spheroidal iron are obtained by adding a spheroidizing agent and an inoculating agent and using a post inoculation method, wherein the spheroidizing agent comprises the following components: 5 to 8 wt percent of Mg, 1 to 2 wt percent of Re, 40 to 50 wt percent of Si, and balance of Fe. The method can make domestically-manufactured cast iron reach high strength and high toughness as cast condition by optimizing spheroidizing and inoculating methods and recarburization treatment under the condition of adding Sn.

The invention discloses a wheel hub of a WTGS, and the wheel hub is characterized by comprising by weight: 3.80%-3.90% of carbon, 1.8%-2.3% of silicon, less than or equal to 0.3% of manganese, less than or equal to 0.02% of phosphor, 0.01%-0.015% of sulfur, 0.04%-0.06% of magnesium, 0.02%-0.08% of tin, 0.015%-0.025% of rare earth, and the balance iron, with the carbon equivalent controlled within4.40-4.66. Without the surface defects of dispersed shrinkage, shrinkage cavity, inclusion, pore, sand inclusion, sand hole and the like, the wheel hub of a WTGS in the invention has a low manufacturing cost, and can effectively control shrinkage and obtain proportional solidification without putting a cold iron.