32results about How to "Overcome casting cracks" patented technology

The invention discloses a hot-top casting process for casting a large-diameter hard aluminium alloy round rod by using a wiping disc. The process comprises the following steps of: a, batching; b, melting; and c, casting, wherein the casting step is a key process. The process protected by the invention is a casting process of a largest-diameter hard aluminium alloy which is put into operation in the country currently. Namely, the process comprises: hot-top casting equipment is used; the wiping disc is configured at the same time; step type casting process parameters are adopted; the suspension height of the wiping disc and the three casting process parameters are searched; and finally, the best casting process of the 7075 aluminium alloy round rod with a diameter of phi582 mm is established. According to the process disclosed by the invention, the crack tendency in the process of casting the large-diameter hard aluminium alloy can be greatly reduced without the bottoming process; the cast round bar has good grain size, thin coarse grain layer and good surface quality; and the turning quantity on the cast rod before extruding is reduced, therefore, the production cost is reduced, and the yield is increased.

A centrifugal casting technology for manufacturing roller of high-speed steel, which is composed of the roller body made of high-C high-W high-speed steel and the core made of cast iron, includes such steps as pouring the molten high-speed steel in the rotating mould of centrifugal machine, applying an electromagnetic field in the pouring and solidifying procedure, adding protecting agnet to the inner surface of roller body, pouring molten iron, cooling to lower than 100 deg.C, demoulding, coarse machining, quenching, tempering, and fine machining. Its advantages are high uniformity without segregation, and compact structure.

The invention discloses a hot top casting process for a phi 784-mm 7xxx-series superhard aluminum alloy round bar. The aluminum alloy round bar is composed of, by mass, 0.25% of Si, 0.4% of Fe, 1.55-1.65% of Cu, 0.25% of Mn, 2.55-2.65% of Mg, 0.19-0.25% of Cr, 5.6-5.7% of Zn, 0.15% of Ti, 0.03% of Zr and the balance Al. The manufacturing process comprises the steps of a, material preparation; b, smelting; c, stirring; d, refining; e, slagging-off; f, heat preservation and standing; g, online thinning; h, online degassing; i, filtration; j, casting; k, homogenizing. Through the process, the defects, such as cracks, component segregation, bright grains, thick grains and loose pores, which often appear when a direct condensation casting technology is adopted for large-diameter superhard aluminum alloy are overcome, and by the adoption of hot top casting, the defects of surface segregation tumors, thick coarse-grain layers and the like are overcome.

The invention discloses an aluminum alloy ingot. The aluminum alloy ingot comprises, by weight , 9.6%-12.0% of Si, 1.5%-3.5% of Cu, less than 0.3% of Mg, less than 1.3% of Fe, less than 1.0% of Zn, less than 0.5% of Mn, less than 0.5% of Ni, less than 0.3% of Sn, 1%.-2%. of Sr, 1%.-2%. of Ti, 1%.-2%. of B and the balance Al. The Si element is added to the aluminum alloy ingot so that strength and toughness of the aluminum alloy ingot are effectively improved, and the Ti and B elements added into the aluminum alloy ingot enables a die-casting product to generate good grain refinement, casting cracks are effectively avoided, the appearance of a casting is improved, the surface quality of the ingot is improved, particularly cold shut of the ingot is reduced, and the impact toughness of the aluminum alloy ingot is effectively improved by 15%-20% on the condition that the strength of the aluminum alloy ingot is not reduced.

The present invention relates to a pipe connecting piece flange. In order to raise utilization rate of material and ensure product quality said invention provides a flange with neck, and it is characterized by that said flange is made up by adopting extrusion casting method, it has no welded seam, its texture possesses continuous streamline structure characteristics, and its streamline form is identical to the member form in alignment.

The invention discloses a stainless steel impeller for a phosphoric acid slurry pump and its preparation method. The preparation method comprises the following steps: (1) smelting: adding raw materials into an intermediate-frequency furnace for smelting; (2) casting: putting round steel, a sand core and chill into a mold, winding the round steel with a gunpowder rope as the core bar of the sand core, kindling the gunpowder rope after completion of molding of the sand core, brushing the interior surface of the mold with an alcohol-based zircon powder paint, carrying out surface drying via a blowtorch, and then carrying out mold closing and casting; and (3) heat treatment: cooling a casting without a riser to a temperature of less than 300 DEG C, then putting the casting into a bogie-hearthresistance furnace for heat treatment, and carrying out cooling again so as to obtain a high-carbon high-chromium ferrite stainless steel impeller product. The high-carbon high-chromium ferrite stainless steel impeller prepared by using the method in the invention can effectively avoid the problem of casting cracks caused by easy precipitation of a brittle phase due to high ferrite content duringcasting.

The invention discloses a 7xxx series aluminum alloy large-specification hollow cast ingot production device and process. The device comprises a crystallizer, a water jacket, a core and a core support, wherein the core support is arranged above the crystallizer through an annular groove formed in the top of the crystallizer, the core support is a circular frame, and a protruding connecting opening is formed in the center of the core support; the connector is fixed to the edge of the core support through reinforcing ribs, a connecting sleeve connected with the core water inlet is arranged in the connector, the upper portion of the connecting sleeve is connected with the connector in a threaded fit mode and extends out of the connector, a lower end opening of the connecting sleeve is arranged in the core water inlet, a connecting plate matched with an end opening of the core is arranged on the outer side wall of the connecting sleeve, and a bolt hole is formed in the connecting plate. The 7xxx series aluminum alloy large-specification hollow cast ingot is prepared by smelting, refining and casting through a specific device and a bipolar uniform fire treatment process, and the formability and the structure of the cast ingot are ensured by utilizing accurate matching of process parameters.

The invention relates to an aluminum alloy ingot. The aluminum alloy ingot is prepared from, by weight percent, 7.2%-11.4% of Si, 1.2%-1.5% of Cu, 0.1%-0.3% of Mg, 0.2%-0.4% of Fe, 1.2%-1.4% of Zn, 0.2%-0.4% of Ni, 0.1%-0.3% of Sn, 1.2%-2.4% of Sr, 2.1%-2.4% of Ti, 2.1%-2.4% of B, 1.2%-1.4% of Sb, 0.3%-0.5% of As, 0.22%-0.44% of RE, 0.4%-1.4% of LaCe, 0.3%-0.5% of Pr and the balance Al and inevitable impurities, wherein the content of the impurities is not larger than 0.1%. The aluminum alloy ingot is good in comprehensive performance, resistant to corrosion and stable in performance.

The invention relates to the technical field of alloys, in particular to an alloy material easy to mold at a time. The alloy material is characterized in that the alloy material comprises, by weight, 0.2-0.4% of zirconium, 0.1-0.3% of zinc, 5-7% of silicon, 0.02-0.1% of strontium, 0.05-0.2% of molybdenum, 0.1-0.3% of nickel, 0.08-0.3% of copper, 0.02-0.04% of scandium, 2-15 ppm of beryllium, and the balance aluminum and less than 0.1% of impurities. Castings cannot crack due to uneven cooling in the cooling process, and the cooling speed is 5% higher than that of conventional alloys. Accordingly, castings cast through one-step molding are smooth in surface and high in strength and impact toughness.

The invention relates to the technical field of aluminum alloys, in particular to a stainless-steel-colored aluminum alloy and a preparation method thereof. The stainless-steel-colored aluminum alloyis prepared from the following components in percentage by weight: 0.38-0.41% of silicon, less than 0.15% of iron, less than 0.1% of copper, less than 0.1% of manganese, 0.48-0.51% of magnesium, lessthan 0.1% of chrome, less than 0.1% of zinc, less than 0.1% of titanium and the balance of aluminum and impurities, wherein the single impurity is less than 0.05%, and the total amount of the impurities is less than 0.15%. The stainless-steel-colored aluminum alloy has the color and gloss of an existing stainless steel profile, has a mirror effect of stainless steel, has the smaller density and lower cost than those of the stainless steel profile, and can replace the existing stainless steel profile to be applied to building decoration.

The invention provides a high wear-resistant aluminum alloy material and a preparation method thereof. The high wear-resistant aluminum alloy material is composed of the following components by weight percentage: 1.23-2.61% of magnesium, 0.23-0.57% of iron, 0.21-0.36% zinc, 0.42-0.92% manganese, 0.38-0.62% cerium, 0.23-0.40% yttrium, 0.63-0.94% titanium, 0.23-0.41% cobalt, 0.12-0.25% scandium, 5.6- 7.8% silicon, the rest is aluminum and a small amount of unavoidable impurities. In the present invention, the addition of cerium and yttrium in the aluminum alloy material can improve the wear resistance of the aluminum alloy material; the addition of cobalt and scandium can improve the toughness of the aluminum alloy material, overcome casting cracks, improve the quality of the aluminum alloy, and improve the quality of the aluminum alloy. Product cost rate. According to the experimental results, the hardness of aluminum alloy products is above 689HV, the strength is above 542MPa, and the qualified rate of flaw detection is above 99%.