This practice covers hot rolling solution heat treatment for aluminum alloy plate. Aluminum alloy ingots or rolling slabs are preheated prior to being hot rolled. Controls shall be adequate to ensure that the equipment is operated in a manner which precludes overheating of the ingot or rolling slab or deleterious contamination by the furnace environment. Metal temperature shall be monitored and controlled to not exceed the maximum temperature prescribed. Non-contact sensors shall be calibrated prior to initial use by an ISO 17025 or A2LA. Noncontact sensors must be compared weekly under operating conditions and temperature to the SAT test instrument/sensor. The accuracy of temperature measuring system(s) shall be tested under operating conditions at least once during each week that the facility is used. For continuous or batch furnaces, the type of survey and procedures for performing the survey shall be established and documented for each particular furnace or furnace type involved. The hot rolling mill solution heat treatment procedures are presented in details. The mechanical properties shall be determined in accordance with test method B557 or B557M. Tensile tests shall be representative of the thinnest and the thickest material to be heat treated; intermediate thickness samples shall be included when necessary to ensure proper production hot rolling mill solution heat treatment. Whenever any qualified equipment is changed or reworked, it shall be requalified unless it is known that the change or rework will not have a detrimental effect upon the properties of products.

1.1 This practice establishes the controls required for hot rolling mill solution heat treatment of the 6xxx series aluminum alloy plate in Table 1 when ASTM material specifications allow use of this process instead of furnace solution heat treatment. For the alloys listed in Table 1, this practice is an alternate process to solution heat treatment in a furnace, such as specified in Practice B918 as the preliminary step for the attainment of T651-type tempers (see ANSI H35.1/H35.1M).

1.2 This practice applies only to hot rolling mill solution heat treatment of plate for the listed aluminum alloys. Precipitation hardening (aging), processing, and equipment calibration for aging shall meet the practice and requirements of Practice B918.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.