Laser additive manufacturing and a method for preparing thin-walled preforms by laser metal deposition and follow-up rolling. This can solve the problems that when the existing laser metal deposition technology prepares the thin-walled preforms, the limit width size of a molten pool at high power affects the forming wall thickness of the preforms so that it is difficult to prepare preforms with wall thickness less than 2 mm, and the problems of poor surface quality and low accuracy of preforms due to convex and concave peaks caused by the interlayer overlapping, but also can solve the problems that a laser beam with a preset trajectory cannot act on the end surfaces of the preforms due to preform deformation caused by residual stress in a printing process so that the preforms cannot be continuously formed.

Laser additive manufacturing and a method for preparing thin-walled preforms by laser metal deposition and follow-up rolling. This can solve the problems that when the existing laser metal deposition technology prepares the thin-walled preforms, the limit width size of a molten pool at high power affects the forming wall thickness of the preforms so that it is difficult to prepare preforms with wall thickness less than 2 mm, and the problems of poor surface quality and low accuracy of preforms due to convex and concave peaks caused by the interlayer overlapping, but also can solve the problems that a laser beam with a preset trajectory cannot act on the end surfaces of the preforms due to preform deformation caused by residual stress in a printing process so that the preforms cannot be continuously formed.

The present invention provides a cell phone frame and a method for manufacturing the same, and relates to the technical field of cell phone accessories. The cell phone frame includes a composite plate, the composite plate encloses a accommodation space for accommodating the cell phone, the composite plate includes a first plate and a second plate, a first side surface of the first plate is provided with striations, the first side surface of the second plate and the first side surface of the first plate are rolled to connect, and the striations of which adjacent ones have a pitch of 0.005 mm to 0.03 mm account for more than 90% of all the striations. According to the cell phone frame provided in the embodiment of the present invention, the first side surface of the first plate is roughened to form striations, which increases the area of the first plate and the second plate subjected to rolling, so that a composite plate produced by combining the first plate and the second plate has a higher bonding strength, thereby ensuring that the cell phone frame is firmer.

The present invention provides a cell phone frame and a method for manufacturing the same, and relates to the technical field of cell phone accessories. The cell phone frame includes a composite plate, the composite plate encloses a accommodation space for accommodating the cell phone, the composite plate includes a first plate and a second plate, a first side surface of the first plate is provided with striations, the first side surface of the second plate and the first side surface of the first plate are rolled to connect, and the striations of which adjacent ones have a pitch of 0.005 mm to 0.03 mm account for more than 90% of all the striations. According to the cell phone frame provided in the embodiment of the present invention, the first side surface of the first plate is roughened to form striations, which increases the area of the first plate and the second plate subjected to rolling, so that a composite plate produced by combining the first plate and the second plate has a higher bonding strength, thereby ensuring that the cell phone frame is firmer.

The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

Laser additive manufacturing and a method for preparing thin-walled preforms by laser metal deposition and follow-up rolling. This can solve the problems that when the existing laser metal deposition technology prepares the thin-walled preforms, the limit width size of a molten pool at high power affects the forming wall thickness of the preforms so that it is difficult to prepare preforms with wall thickness less than 2 mm, and the problems of poor surface quality and low accuracy of preforms due to convex and concave peaks caused by the interlayer overlapping, but also can solve the problems that a laser beam with a preset trajectory cannot act on the end surfaces of the preforms due to preform deformation caused by residual stress in a printing process so that the preforms cannot be continuously formed.

Laser additive manufacturing and a method for preparing thin-walled preforms by laser metal deposition and follow-up rolling. This can solve the problems that when the existing laser metal deposition technology prepares the thin-walled preforms, the limit width size of a molten pool at high power affects the forming wall thickness of the preforms so that it is difficult to prepare preforms with wall thickness less than 2 mm, and the problems of poor surface quality and low accuracy of preforms due to convex and concave peaks caused by the interlayer overlapping, but also can solve the problems that a laser beam with a preset trajectory cannot act on the end surfaces of the preforms due to preform deformation caused by residual stress in a printing process so that the preforms cannot be continuously formed.

The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation:
μ.sub.C,material 1>μ.sub.C,material 2,
where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.

The invention relates to a method for producing a steel composite in which at least two steel sheets that consist of different steel grades are placed against each other, hot rolled together, and then possibly cold rolled and in which after the rolling, the composite material, which is thus produced from at least two layers with different steel compositions, is diffusion annealed, wherein the annealing temperature is set so as to select the chemical potential of the steel materials to correspond to the following equation:
μ.sub.C,material 1>μ.sub.C,material 2,
where material 1 has a lower carbon content than material 2 so that an uphill diffusion of carbon takes place between material 1 and material 2.