Method for producing hot rolled hollow sections having a rectangular cross-section and small edge radii

A method for producing a hot rolled hollow section made of steel and having a rectangular or square cross section, comprising:

• producing a substantially round pipe blank having a defined nominal outer diameter by seamless hot-rolling or cold-finishing and welding;
• forming the pipe blank in a rolling mill at a forming temperature into a hollow section having visible edges defined by a value of ≦1.5×t, wherein t is a wall thickness of the hollow section;
• and
• determining the nominal outer diameter of the pipe blank as a function of a reduction ratio to be achieved of the pipe blank and dimensions to be achieved of the hollow section, wherein the reduction ratio lies within a range of −2% to −13% and is determined by the formula:
• Reduction ratio R [%]=[(2×(H+B))−π×D]×100%/[2×(H+B)],
• wherein
• H is a height of the hollow section,
• B is a width of the hollow section,
• D is an outer diameter of the pipe blank at the forming temperature and before the forming step.