Method for manufacturing aluminum alloy section material for floor of rail transport car body

The invention discloses a method for manufacturing an aluminum alloy section material for a floor of a rail transport car body. The method comprises the following steps of: (a) preparing raw materials of cast rod; (b) smelting a cast rod; (c) casting the cast rod; (d) performing homogenization treatment; (e) performing surface treatment of the cast rod, (f) heating the cast rod, (g) heating a mould, (h) extruding, (i) performing on-line quenching, and (j) aging to obtain the section material. The method can strictly control various parameters in the process steps, endows the aluminum alloy section material with higher cross-section and better overall performance, meets the requirements for application in aluminum alloy section material car bodies, reduces the manufacturing cost and weight of the car body, and eliminates the problems such as heavy weight of steel structure car body, difficulty in repair and maintenance and high cost of auxiliary equipment. Besides, the energy consumption is 1/5 that of stainless steel, the water consumption is 1/5 that of stainless steel carriages, the weight of carriage is reduced by 1/3, the performance of product is excellent, the proof strength (non-proportional extension strength) can reach more than 255 MPa, the tensile strength can reach more than 300 MPa, and the percentage elongation after fracture can reach more than 11%.