32results about How to "Control carbon content" patented technology

The invention discloses a method for manufacturing a bimetallic metallurgical composite wear-resisting tube blank, which comprises the following steps: firstly, spraying a water-based zircon powder coating onto a metal tube die after being baked to between 200 and 300 DEG C, wherein the spraying thickness is 1.0 to 3.0mm; secondly, centrifugally casting external liquid metal on the metal tube dieafter being baked to between 200 and 350 DEG C, cooling the metal tube die after casting, beginning to cast internal liquid metal into the metal tube die when an internal surface temperature of the outer layer is cooled to a temperature lower than a solidus temperature of the external metal; and finally, pouring the internal liquid metal into the metal tube die for centrifugal casting, cooling the metal tube die after casting, and stopping cooling when the outer layer and the inner layer are completely solidified, then the outer layer and the inner layer are metallurgically fused completely, wherein the outer layer is made of a plain carbon steel material or a low-alloy high-strength steel material and the inner layer is made of a high-chromium white cast iron material. The invention alsodiscloses the bimetallic metallurgical composite wear-resisting tube blank manufactured by the method. The outer-layer metal and the inner-layer metal of the tube blank manufactured by the method canbe metallurgically fused completely; the qualification rate is improved; and the use safety is high.

The invention discloses a production method for low-carbon high-chromium steel. The production method comprises the following steps: primarily melting molten steel by adopting a converter, wherein the final tapping temperature is controlled at 1670-1690DEG C, the C content of tapping liquid steel is regulated to be 0.04-0.06wt% and the oxygen activity is regulated to be 600*10<-6> to 700*10<-6>, and ferrochrome alloy is quantitatively added according to a ratio of 40-50kg / t liquid steel in the steel tapping process; performing primary refining to the primarily molten liquid steel in a ladle refining furnace, wherein the ferrochrome alloy is added when the primary refining starts to regulate the content of Cr in the liquid steel to be 3.6-4.0wt%, and the final tapping temperature of the primary refining is controlled to be 1645-1655DEG C; carrying out decarburization treatment to the primarily refined liquid steel in an RH furnace to regulate the content of C to be 0.02% below; then carrying out secondary refining to the decarburized liquid steel in the ladle refining furnace to finally obtain the low-carbon high-chromium steel, wherein the ferrochrome alloy is added when the secondary refining starts to regulate the content of Cr in the liquid steel to be 3.8-4.2wt%, and the final tapping temperature of the secondary refining is controlled to be 1595-1605DEG C. The low-carbon high-chromium steel is obtained by adopting the method.

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 belongs to the field of metal sulfide nanomaterials, and particularly relates to a method for preparing carbon-loaded metal sulfide nanocomposites by electrospinning, including (1) preparing a spinning precursor solution: mixing thiacalixarene metal clusters and Spinning aids were dissolved in DMF and mixed together; (2) Preparation of nanofibers by electrospinning: Inhale the obtained spinning precursor solution into the syringe, adjust the flow rate and voltage of the syringe pump, and the distance between the spinning needle and the receiving plate , for spinning, accepting the nanofiber mat with a receiving plate; (3) pre-oxidizing the nanofiber mat: pre-oxidizing the collected nanofiber mat; (4) N 2 Carbonization under atmosphere: Carbonize the pre-oxidized nanofiber mat, and then cool down naturally to obtain the target product. The target product of the present invention has ideal electrochemical performance and good capacitance characteristics. The sheet carbon material is directly used as an electrode, which can eliminate additives or impurities such as binders and improve energy capacity and performance.

The invention relates to a method for preparing nanometer tungsten carbide powder from liquid-state alkane through back flow carbon covering. Sodium tungstate is used as a tungsten source, and a liquid-state alkane mixture (C11 to C16) is used as a carbon source. The invention has the sequential process steps of material preparation, back flow, drying, material charging, high-temperature heat treatment and sampling. The back flow time and the back flow temperature of raw materials are controlled, precursor powder with different carbon contents can be prepared, and high-purity nanometer tungsten carbide powder can be prepared through the heat treatment process. The tungsten carbide powder prepared by the method has the average granularity between 30 and 60 nm and the average grain finenessnumber between 20 and 30 nm. The method of the invention has simple process and lower cost. Compared with an ordinary heat reducing method, the invention saves energy sources, and can easily realize the scale preparation.