GMW GMW15619 PDF

This standard defines the requirements for Tailor Rolled Blanks (TRB) and Tailor Rolled Tubes (TRT) used in the manufacture of steel body structure parts. Tailor rolled blanks shall be produced from continuous cast hot or cold rolled coils/strip (usually supplied in thicknesses >1.75 mm) that are cold rolled to specific multiple thicknesses, annealed or as-rolled, and galvanized (if applicable), and then leveled and cut to specified blank sizes. Tailor rolled blank products shall be used for cold formed stampings and hot formed stampings. Tailor rolled tubes shall be manufactured from tailor rolled blanks that are formed into circular tubes along the longitudinal direction and joined by a laser welded seam.

Material Description. The material designation is defined by the tailor rolled segment thickness, GMW base metal specification number, steel product type, minimum yield strength, minimum tensile strength, galvanized coating type, and the finish type. The steel product type is designated by Cold Rolled (CR) for cold rolled products. GMW2 low carbon and GMW3032 high strength steel grades shall be specified by the steel type and a three digit numeral to designate the minimum yield strength of each tailor rolled segment in megapascals (MPa). The minimum yield strength, minimum ultimate tensile strength, and minimum total elongation shall be established by statistical analysis of tensile test results of TRB or TRT samples. A designation of steel type shall be added to solid solution strengthened grades (P and IF) and high strength Low Alloy (LA) steels. An F designation may be added following an LA steel type to specify the steel as inclusion controlled. Bake hardenable (B0 and B2) steel grades are not applicable to tailor rolled blanks. The steel grades will correspond to the chemical composition requirements of the applicable tables of GMW2 and GMW3032. The galvanized coating type shall be specified by the Electrogalvanized Coating for (EG), or Hot Dip (HD) for galvanized coating followed by the minimum coating weight per sheet side. The finish type, an alpha character, will designate the finish as either Exposed (E), Semi- Exposed (Z), or Unexposed (U). Products without a coating (i.e., bare steel) shall have the word "UNCOATED" added to the call out after the steel type, but before the finish designation. Electrogalvanized coatings shall conform to the requirements of GMW11. Hot dip galvanized coatings shall conform to the requirements of GMW8. Tailor Rolled Blanks produced from low carbon boron alloy steel substrates for hot stamping applications shall conform to GMW14400 uncoated or aluminized coated requirements. The above descriptive items are used together to form the coding system. Examples of the coding system for engineering part drawings and manufacturing engineering documents are shown in Section 8.

Symbols. Not applicable.

Typical Applications. Typical applications for tailor rolled blanks include (but not limited to) body structure panels such as roof bows, cross sills, rocker panels, cross members, tunnel reinforcements, radiator support assembly tie bars, and B-pillars. Tubular applications include instrument panel cross car beams.