Heating and forming method for cold bending sectional steel and cold bending sectional steel produced by the same

Abstract

The invention discloses a method for heat forming of cold-pressing steel and cold-pressing steel produced by the method. The invention has the advantages of capability of increasing the welding quality. The method for heat forming of cold-pressing steel is characterized in that the method includes the steps including that firstly, circular vertical angle section steel block is manufactured by an ordinary hole-typed cold-pressing forming machine group, secondly, the formed circular vertical angle section steel block is on-line heated by a heating device to enable the blank in the portion of the circular angle of the circular vertical angle section steel to form an austenite structure, thirdly, the circular vertical angle section steel block is pressed to form sharp vertical angle section steel. The blank in the position of the circular portion is transformed into the austenite structure after being on-line heated the conventional circular vertical angle section steel block by the heating device, and the heating temperature is defined by the austenite transforming temperature of various steel, thereby the deformed portion and the dangerous portion can be processed thermoplastic, and the plasticity and fluidity of the deformed portion and the dangerous portion can be improved, enabling the circular vertical angle section steel block to be not easy to deform and difficult to be cracked in the pressed opening, consequently, the integral load of the machine group is greatly reduced.

Description

technical field [0001] The invention relates to a steel processing method and the produced steel, in particular to a cold-formed steel heating forming method and the produced cold-formed steel. Background technique [0002] At present, my country's national economy continues to develop rapidly, the market demand for cold-formed steel is increasing day by day, the scope of application is expanding, and the market prospect is very broad. In its application field, the advantages of cold-formed steel are more and more recognized by users. It is an economical cross-section and high-efficiency steel. Compared with similar hot-rolled profiles, it can save 15-30% of metal, and it has less investment and flexible production. It can meet the needs of users. All kinds of requirements show its unique advantages in the development of personalized market. It has become an irresistible trend to widely use cold-formed steel to replace hot-rolled steel and other varieties. Compared with for...

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Problems solved by technology

[0003] However, the conventional cold bending process encountered insurmountable difficulties in the production of high-precision sharp right-angle, high-strength and difficult-to-form cold-formed steel products

For example, when developing the middle beam of cold-formed railway freight cars, the traditional cold-formed steel production process is adopted. For thick plates above 4.0mm, the fillet radius will not be lower than the plate thickness, and the relative bending radius is usually above 1.25, so For blanks with a plate thickness of 10mm or 12mm for the production of railway freight car middle beams, the radius of the outer fillet will be more than 22mm. The 22mm cold-formed center beam will lead to a sharp increase in product cracking rate and unit load, which is a very high price; and when the vehicle factory welds the beam, it is required to ensure that the maximum welding fillet of the center beam is less than 8 mm to ensure The quality of the weld seam, obviously the traditional cold bending process ability cannot meet the user's requirements at all

For example, Hankou Steel Rolling Plant of Wuhan Iron and Steel Group disclosed the invention patent "Cold-formed middle beam for railway vehicle manufacturing" (patent publication number: CN1515365A) on July 28, 2004 and the utility model patent " "Cold-formed middle beam for railway vehicles" (patent authorization publication number: CN2717559Y)" involves a process of producing the middle beam of railway wagons with large outer fillet radius by using the traditional simple cold bending method. The main problems are: the radius R of the outer fillet is too large, the rigidity is not enough, there are tiny cracks on the corner that are difficult to detect, and the center beam is twisted after grinding, etc., which affect its wide application

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