80results about How to "Reduce white mouth tendency" patented technology

The invention discloses a low-alloy gray cast iron material for truck brake drums and a preparation method thereof, belonging to the technical field of gray cast iron materials. The material mainly comprises the following chemical components in percentage by mass: 3.00-3.70% of C, 1.5-2.8% of Si, 0.38-1.5% of Mn, at most 0.04% of S, at most 0.08% of P, 0.02-0.04% of Mg, 0.20-0.50% of Cr, 0.2-0.5% of V, 0.2-0.45% of Mo, 0.04-0.10% of Sn and the balance of iron. The method comprises the following steps: (1) molten iron smelting; (2) inoculation; and (3) casting. The invention aims to provide a low-alloy gray cast iron material for truck brake drums, which has the advantages of excellent resistance, excellent wear resistance and ideal comprehensive mechanical properties, and a preparation method thereof. The method is used for preparing the gray cast iron material.

The invention discloses a hydraulic pump body casting process, the process steps are as follows: moulding-casting material pretreatment-melting-spheroidizing treatment-pouring-heat treatment-stabilizing treatment-gas nitriding treatment-machining-inspection and storing-finished product; and the casting process is simple and practical, and low in cost, the casted hydraulic pump body is dense in tissue, free of shrinkage porosity and cavity, white cast and crack defects, good in tensile strength, and high in hardness.

The invention discloses a high-strength-and-toughness cast iron heavy-duty automobile brake drum. The brake drum is characterized in that brake drum comprises 3.55-3.85wt% of C, 2.35-2.75wt% of Si, 0.45-0.85wt% of Mn, 0.02-0.06wt% of P, 0.01-0.04wt% of S, 0.06-0.12wt% of Ti, 0.02-0.08wt% of Sn, 0.01-0.04wt% of Sb, 0.008-0.05wt% of Mg, 0.015-0.035wt% of RE, and the balance Fe. The making technology of the brake drum sequentially comprises the following steps: weighing raw materials in proportion, carrying out alloy melting, carrying out creeping and inoculation, carrying out cast molding, cleaning, and machining. Compared with the prior art, the technology has the advantages of best thermal fatigue resistance, good deformation resistance, good cooperation of strength, ductility, hardness and wear resistance, and good casting and machining properties.

The invention discloses a casting process for high-strength vermicular graphite cast iron materials. The casting process specifically comprises the steps of a, a furnace charge comprises, by weight, 40%-60% of a steel scrap and 40%-60% of raw iron, and the proportioned furnace charge is put into a medium-frequency furnace for smelting; b, after molten iron smelting is completed, the molten iron refining temperature is controlled to be 1520DEG c-1550DEG c, and heat preservation is carried out for more than 10 minutes; and c, a primary silicon-calcium-barium nucleating agent and a rare-earth magnesium vermicularizing agent are added into a molten iron ladle, wherein the weight of the silicon-calcium-barium nucleating agent is 0.5%-0.8% of the amount of the produced molten iron, and the molten iron undergoes the vermicularizing treatment by adopting an in-ladle pour-over method; d, the ladle stream secondary inoculation process is adopted, the silicon-barium inoculant with the weight accounting for 0.1%-0.2% of the weight of the produced molten iron is added for secondary inoculation; and e, the inoculated molten iron is poured into a sand mold casting mold, the casting time is controlled within 10 minutes, and the casting temperature is controlled between 1400DEG c-1460 DEG c. According to the casting process, the shrinkage porosity tendency of a product is reduced, forming of nucleation when the molten iron is solidified can be promoted, and the performance of the vermicular graphite cast iron materials can be improved.

The invention discloses a high-intensity gray pig iron inoculator and a preparation method thereof and belongs to the technical field of casting. The high-intensity gray pig iron inoculator comprises the following chemical components in percentage by weight: 65 to 72 percent of Si, 0.5 to 1.2 percent of Al, 0.5 to 1.5 percent of Zr, 0.6 to 1.8 percent of RE, 4.0 to 6.0 percent of Mn, 0.4 to 1.2 percent of Sn (or 0.1 to 0.4 percent of Sb), less than 0.2 of C, less than 0.02 of S, less than 0.05 of P, and the balance of iron and unavoidable impurities. The inoculator can obviously reduce chilling tendency, refine graphite and reduce wall thickness and sensitivity of tissues and obviously increase pearlite content, so that tensile strength of gray pig iron is improved. For base iron with the same components, compared with a common 75 silicon iron inoculator, the high-intensity gray pig iron inoculator has the advantage that the tensile strength of cast iron applying the high-intensity gray pig iron inoculator can be improved by 30 to 60MPa.

The invention provides a microalloying high-strength gray pig iron piece and a smelting method thereof and relates to the field of metal casting. The gray pig iron piece comprises, by weight percent, 2.92%-3.48% of C, 1.52%-2.36% of Si, 0.22%-0.78% of Mn, 0.15%-0.5% of Cr, 0.3%-0.78% of Cu, 0.011%-0.098% of Nb, 0.02%-0.1% of V, 0.015%-0.025% of Ti and the balance iron and other traces of unavoidable impurities. A casting piece base body is intensified through microalloying, the intensity and the rigidity of the casting piece are improved, a high-efficiency nucleating agent is added, graphite form, hardness and texture uniformity can be effectively improved, the sensibility is reduced, the mechanical performance of the gray pig iron piece is improved, by adopting the in-mold inoculation manner, the utilization rate of the nucleating agent can be improved, the inoculation effect is improved, and the cost is reduced.

A vermicular graphite cast iron cylinder cover material of a heavy-duty diesel oil engine comprises the following raw materials in percentage by weight: 3.60-3.90% of C, 1.90-2.50% of Si, 0.50-0.70% of Mn, 0.4-0.6% of Mo, 0.70-0.85% of Cu, 0.2-0.4% of Cr, 0.01-0.025% of Mg, 0.025-0.04% of Re, not greater than 0.070% of P, not greater than 0.015% of S, and the balance Fe and inevitable impurities.A preparation technology comprises the steps of pressing from the bottom of a ladle and nucleating by a ladle bottom pouring method; supplementing a nucleating agent while 78-85% of molten iron is output; and then nucleating along with stream. According to the preparation technology adopting the design, the comprehensive mechanical property of the material is obviously improved; and moreover, thevermicularity and the pearlite content are stable; and the production cost is decreased.

The invention discloses an inoculant for a ferritic nodular cast iron and a preparation method of the inoculant, and the inoculant can be used for solving the problems that the nodular graphite cast iron prepared by an existing inoculant is less in graphite nodule quantity, low in ferrite content and poor in extensibility and impact ductility. The inoculant for the ferritic nodular cast iron comprises the following chemical compositions in percentage by mass: 65-70% of Si, 1.0-5.0% of Bi, 2.0-5.0% of Ca, 1.0-4.0% of Ba, less than 0.5% of Al, less than 0.05% of T1, less than 0.4% of Mn, less than 0.02% of S, less than 0.05% of P, and the balance of Fe; and the inoculant is prepared by smelting and granulating the raw materials. The ferritic nodular cast iron produced by using the inoculant can accelerate graphite nucleation, reduce the chilling tendency, increase the graphite nodule quantity, improve the graphite nodule element integration action, further improve the ferrite content under a cast condition, and improve the extensibility and impact ductility of ductile iron.

The invention discloses a method for preparing a base of a vertical annealing furnace. The method provided by the invention is characterized in that a lost foam casting technology is adopted; molten iron is injected into a mold from the bottom to form a casting; a pour-over spheroidizing technology is adopted; and a spheroidizing inoculation technology is adopted. The base obtained by the method has advantages of good mechanical properties, good flexibility, high tensile strength, high compression strength, low rejection rate, high heat resistance, high fatigue resistance, and large elongation.

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 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 discloses a preparing method of gray iron inoculant. The preparing method comprises the following steps that 66-70% of Si, 1-3% of Zr, 1-2% of Ca, 0-2.5% of Mn, 0.5-1.5% of Fe3O4, 0.5-1% of carburant and the balance Fe and inevitable microelements are evenly mixed, smashed, melted, stirred, poured, quickly frozen and smashed for standby use. The invention further discloses application of the gray iron inoculant. By means of the gray iron inoculant, the comprehensive performance of gray iron can be improved, and the inoculating efficiency is improved.

The invention discloses a preparation method of a gray pig iron nucleating agent. The preparation method comprises the following steps that 66%-70% of Si, 1%-13% of Zr, 1%-2% of Ca, 0-2.5% of Mn, 0.5%-1.5% of Fe3O4 and the balance Fe and inevitable trace elements are evenly mixed, smashed, smelted, stirred, cooled and smashed for use. The invention further discloses application of the gray pig iron nucleating agent. According to the gray pig iron nucleating agent, the comprehensive performance of gray pig iron can be improved, and nucleating efficiency is improved.

The invention discloses a high-strength wear-resistant gray cast iron and an inoculation process thereof, and relates to the technical field of wear-resistant gray cast iron inoculation. The present invention includes the weight ratio of each component as follows: C: 4.28%, Cr: 0.05%, Mn: 1.57%, Si: 0.38%, Ti: 0.38%, P<0.02%, S<0.15%, B: 0.67 %, Ni: 0.96%, Mo: 0.082%, V: 0.11%, Sn: 0.09%, and the rest is Fe. The present invention adopts inoculation treatment in front of the furnace and in the ladle during the manufacture of gray cast iron, mixes and bakes the silicon-barium inoculant and rare earth ferrosilicon to 100-150°C, and then adds them into the molten iron along with the flow of the tapping trough for follow-up Flow inoculation treatment, promotes nucleation, inhibits growth, refines grains, promotes graphitization, reduces whitening tendency; improves the uniformity of the section, improves the mechanical properties of gray cast iron, and improves the wear resistance of gray cast iron.

The invention discloses a vermiculizer for preparing vermicular graphite cast iron, and belongs to the field of cast iron material production. The vermiculizer solves the problems that an existing vermiculizer is not high in vermicular rate and is unstable in reaction during preparation of vermicular graphite cast iron. The vermiculizer is prepared by melting rare earth magnesium and a rare earth silicon-iron alloy, and consists of the following element components in parts by mass: 14-20 parts of rare earth, 36-40 parts of silicon, 4-10 parts of magnesium, the balance iron and a little impurity elements. A preparation method for the vermiculizer comprises the following steps of: (1) preparing the rare earth magnesium and the rare earth silicon-iron alloy into raw materials with grain size being about 5-10 mm; (2) weighing weight of each raw material according to component proportion of set elements; and (3) smelting for 60 minutes in a vacuum induction furnace, and cooling to obtain the rare earth magnesium-silicon-iron alloy vermiculizer. The vermiculizer can be used for producing vermicular iron parts.

The invention discloses a grey cast iron inoculant. The formula of the grey cast iron inoculant comprises the following components in percentage by weight: 66-70% of Si, 1-3% of Zr, 1-2% of Ca, 0-2.5% of Mn, 0.5-1.5% of Fe3O4 and the balance of Fe and inevitable trace elements. By adopting the grey cast iron inoculant disclosed by the invention, the comprehensive performance of the grey cast iron can be improved, and the inoculating efficiency is improved.