Abstract: A preforming method for a high-strength steel variable-diameter tubular part is provided, which belongs to the technical field of metal forming process. The preforming method for a high-strength steel variable-diameter tubular part includes: selecting a tubular blank; and preparing a tubular blank forming mold, where the tubular blank forming mold includes a preforming mold and a final forming mold; sealing and pressurizing the tubular blank; heating the tubular blank by using electrodes; preforming the tubular part at a constant temperature; maintaining a temperature Tl and moving the preformed tubular part to the final forming mold; finally forming the tubular part. Through two steps of operation of preforming and final forming, and maintaining a temperature during moving the tubular blank between the two steps, so that the conversion of intrametallic structure between the two steps is improved, and the performance of the tubular part is improved.

Abstract: A method for making a profile with a micro-hole, in particular using a continuous composite extrusion process, comprises embedding, in a position in a matrix of the profile to be formed where a micro-hole is to be formed, a continuous wire having a shape and size consistent with that of the micro-hole; sawing a composite profile with the wire obtained by extrusion to a desired length; and removing the wire from the sawed composite profile using a predetermined physical or chemical method without changing the matrix of the composite profile so that the micro-hole of the predetermined size and shape is formed in the predetermined position in the profile. This method is simple, does not require any large, expensive, and sophisticated equipment, can produce continuous micro-holes of different specifications, and can be used in a wide variety of applications.

Abstract: A preforming method for a high-strength steel variable-diameter tubular part is provided, which belongs to the technical field of metal forming process. The preforming method for a high-strength steel variable-diameter tubular part includes: selecting a tubular blank; and preparing a tubular blank forming mold, where the tubular blank forming mold includes a preforming mold and a final forming mold; sealing and pressurizing the tubular blank; heating the tubular blank by using electrodes; preforming the tubular part at a constant temperature; maintaining a temperature T1 and moving the preformed tubular part to the final forming mold;finally forming the tubular part. Through two steps of operation of preforming and final forming, and maintaining a temperature during moving the tubular blank between the two steps, so that the conversion of intrametallic structure between the two steps is improved, and the performance of the tubular part is improved.

Abstract: Disclosed is a processing technology for inhibiting weld coarse grains of magnesium alloy profiles, including the following steps: preparation of a magnesium alloy ingot, homogenization, scalping, extrusion, pre-stretching at room temperature, solution treatment, quenching, stretching correction, artificial aging, etc. The processing technology can effectively control the production of weld coarse grains in extrusion and heat treatment processes of magnesium alloy profiles, and all property indexes of final products are higher than standard requirements.

Abstract: Disclosed is a processing technology for inhibiting weld coarse grains of magnesium alloy profiles, including the following steps: preparation of a magnesium alloy ingot, homogenization, scalping, extrusion, pre-stretching at room temperature, solution treatment, quenching, stretching correction, artificial aging, etc. The processing technology can effectively control the production of weld coarse grains in extrusion and heat treatment processes of magnesium alloy profiles, and all property indexes of final products are higher than standard requirements.

Abstract: A method for making a profile with a micro-hole, in particular using a continuous composite extrusion process, comprises embedding, in a position in a matrix of the profile to be formed where a micro-hole is to be formed, a continuous wire having a shape and size consistent with that of the micro-hole; sawing a composite profile with the wire obtained by extrusion to a desired length; and removing the wire from the sawed composite profile using a predetermined physical or chemical method without changing the matrix of the composite profile so that the micro-hole of the predetermined size and shape is formed in the predetermined position in the profile. This method is simple, does not require any large, expensive, and sophisticated equipment, can produce continuous micro-holes of different specifications, and can be used in a wide variety of applications.