Abstract: The present disclosure provides a high-efficient rolling process for magnesium alloy sheet. Parameters of the rolling process are: the rolling speed of each rolling pass is 10-50 m/min, the rolling reduction of each rolling pass is controlled to be 40-90%, and both the preheating temperature before rolling and the rolling temperature of each rolling pass are 250-450° C. The present disclosure also provides a preparation method for magnesium alloy sheet, comprising: 1) preparing rolling billets; 2) high-efficient hot rolling; and 3) performing annealing. The rolling process can improve the mechanical performance especially, the strength and ductility of the sheet.

Abstract: Disclosed is a method for manufacturing an equal-strength steel thin-wall welding component with an aluminum or aluminum-alloy plating, wherein the plating comprises an intermetallic compound alloy layer in contact with the base body and a metal alloy layer on the intermetallic compound alloy layer; the plating is not removed or thinned before or during welding; and by presetting a welding gap and using a carbon-manganese-steel welding wire, a welding process and protective gas for welding, the tensile strength of a welding seam of the welding component after hot stamping processing is greater than the tensile strength of a base metal, and the elongation of a welded joint is greater than 4% Further disclosed are a welding wire for welding and an equal-strength steel thin-wall welding component with an aluminum or aluminum-alloy plating.

Abstract: Disclosed is a different-strength steel welding component with an aluminum or aluminum-alloy plating formed by means of butt welding of a high-strength steel plate and a low-strength steel plate, and each of the high-strength steel plate and the low-strength steel plate comprises a base body and at least one pure aluminum or aluminum-alloy plating on a surface of the base body. The tensile strength of a welding seam of the welding component after hot stamping is greater than the tensile strength of a low-strength steel base metal, and the elongation is greater than 4%, such that application requirements of the welding component in the field of automobile hot stamping are met. The present disclosure also relates to a method for manufacturing a different-strength steel welding component with an aluminum or aluminum-alloy plating and a welding wire used in the method.

Abstract: A film forming treatment agent for a composite chemical conversion film for magnesium alloy, and a film forming process method, and a composite chemical conversion film are provided. Components of the film forming treatment agent for a composite chemical conversion film for magnesium alloy comprise a water solution and a suspension of reduced graphene oxide flakes to the water solution. The water solution comprises strontium ions at 0.1 mol/L to 2.5 mol/L and phosphate ions at 0.06 mol/L to 1.5 mol/L, and pH of the water solution is 1.5 to 4.5. Concentration of the reduced graphene oxide varies between 0.1 mg/L and 5 mg/L. The film forming process method for a composite chemical conversion film for magnesium alloy comprises the following steps of: 1) pretreatment on surface of magnesium alloy matrix; 2) immersion of magnesium alloy matrix in the film forming treatment agent; and 3) removal of magnesium alloy pieces for drying in air.

Abstract: A resistance spot welding method of galvanized high-strength steel with good joint performance, in which three welding pulses are used within one spot welding schedule. The method includes applying a first welding pulse and a second welding pulse which are used for generating a nugget and suppressing the generation of liquid metal embrittlement (LME) cracks, respectively. The first welding pulse generates a nugget having a diameter of 3.75T1/2-4.25T1/2 in which T represents a plate thickness. The second welding pulse causes the nugget to grow at a rate less than a rate of growth during the first welding pulse. A third welding pulse, which is a tempering pulse, is applied for improving plasticity of a welding spot.

Abstract: Provided is a steel welding component having a steel welding blank with an aluminum or aluminum alloy coating. The welding blank is composed of a steel substrate and coatings comprising an intermetallic compound alloy layer contacting the substrate, and a metal alloy layer on the intermetallic compound alloy layer. On at least one of the coating surfaces of the welding blank, the coating within an area to be welded has been totally removed, and an end face of the coating on the side of the coating within the area to be welded removed has an angle of ? being 0-80° with a plane vertical to a surface of the substrate which is parallel to the welding seam. Also provided are welding methods for the steel welding component. The steel welding blank provided ensures the tensile strength, elongation, and corrosion resistance of a hot-stamped welded joint.

Abstract: A die-casting magnesium alloy. The die-casting magnesium alloy comprises, by mass percent, 1% to 5% of La, 0.5% to 3% of Zn, 0.1% to 2% of Ca, 0.1% to 1% of Mn and the balance Mg and other inevitable impurities. The die-casting magnesium alloy manufacturing method comprises smelting, refinement and die-casting. The die-casting magnesium alloy has good mechanical performance, die-casting performance and heat conduction performance.

Abstract: A steel welding component with an aluminum or aluminum alloy coating, using a steel welding blank with an aluminum or aluminum alloy coating. The welding blank is composed of a steel substrate (1) and coatings (2, 2?); the coating (2) comprises an intermetallic compound alloy layer (21) which contacts the substrate (1), and a metal alloy layer (22) on the intermetallic compound alloy layer (21); on at least one of the coating surfaces of the welding blank, the coating (2) within an area (3) to be welded of the welding blank has been totally removed, and an end face (23) of the coating (2) on the side of the coating within the area (3) to be welded removed has an angle of ? with a plane vertical to a surface (11) of the substrate (1) which is parallel to the welding seam, wherein ? is 0-80°. Also provided are welding and preparation methods for the steel welding component.

Abstract: A resistance spot welding method of galvanized high-strength steel with good joint performance, wherein: three welding pulses are used within one spot welding schedule; a first welding pulse and a second welding pulse are used for generating a nugget and suppressing the generation of liquid metal embrittlement (LME) cracks, wherein the first welding pulse generates a nugget having a diameter of 3.75T½-4.25T½ in which T represents a plate thickness; the second welding pulse causes the nugget to grow slowly; and a third welding pulse which is a tempering pulse is used for improving plasticity of a welding spot. A time t1 of the first welding pulse is set and a welding current I1 of the first welding pulse is obtained through tests, and the welding current I1 of the first welding pulse is a welding current upon generating the nugget having the diameter of 3.75T½-4.

Abstract: A high-efficient rolling process for magnesium alloy sheet. The process is a rolling process for rolling billets. Parameters of the rolling process are: the rolling speed of each rolling pass is 10˜50 m/min, the rolling reduction of each rolling pass is controlled to be 40˜90%, and both the preheating temperature before rolling and the rolling temperature of each rolling pass are 250˜450° C. A preparation method for magnesium alloy sheet. The method comprises the steps of: 1) preparing rolling billets; 2) high-efficient hot rolling: controlling the rolling speed of each rolling pass to be 10˜50 m/min, controlling the rolling reduction of each rolling pass to be 40˜90%, and controlling both the preheating temperature before rolling and the rolling temperature of the each rolling pass to be 250˜450° C.; and 3) performing annealing.

Abstract: A data transmission method and a data transmission device are provided. The method includes: establishing, by a transmitting end, N different first paths between the transmitting end and a receiving end in an established network; splitting, by the transmitting end, a fixed-length data frame into N first fragments; transmitting, by the transmitting end, the first fragments to the receiving end through the corresponding first paths respectively; splitting, by the transmitting end, the data frame into N-M second fragments in a case that a failure occurs in M of the first paths during transmission of the data frame; establishing, by the transmitting end, N-M different second paths between the transmitting end and the receiving end; transmitting, by the transmitting end, the second fragments to the receiving end through the corresponding second paths respectively.

Abstract: A film forming treatment agent for a composite chemical conversion film for magnesium alloy, and a film forming process method, and a composite chemical conversion film are provided. Components of the film forming treatment agent for a composite chemical conversion film for magnesium alloy comprise a water solution and a suspension of reduced graphene oxide flakes to the water solution. The water solution comprises strontium ions at 0.1 mol/L to 2.5 mol/L and phosphate ions at 0.06 mol/L to 1.5 mol/L, and pH of the water solution is 1.5 to 4.5. Concentration of the reduced graphene oxide varies between 0.1 mg/L and 5 mg/L. The film forming process method for a composite chemical conversion film for magnesium alloy comprises the following steps of: 1) pretreatment on surface of magnesium alloy matrix; 2) immersion of magnesium alloy matrix in the film forming treatment agent; and 3) removal of magnesium alloy pieces for drying in air.

Abstract: A die-casting magnesium alloy. The die-casting magnesium alloy comprises, by mass percent, 1% to 5% of La, 0.5% to 3% of Zn, 0.1% to 2% of Ca, 0.1% to 1% of Mn and the balance Mg and other inevitable impurities. The die-casting magnesium alloy manufacturing method comprises smelting, refinement and die-casting. The die-casting magnesium alloy has good mechanical performance, die-casting performance and heat conduction performance.

Abstract: A data transmission method and a data transmission device are provided. The method includes: establishing, by a transmitting end, N different first paths between the transmitting end and a receiving end in an established network; splitting, by the transmitting end, a fixed-length data frame into N first fragments; transmitting, by the transmitting end, the first fragments to the receiving end through the corresponding first paths respectively; splitting, by the transmitting end, the data frame into N-M second fragments in a case that a failure occurs in M of the first paths during transmission of the data frame; establishing, by the transmitting end, N-M different second paths between the transmitting end and the receiving end; transmitting, by the transmitting end, the second fragments to the receiving end through the corresponding second paths respectively.