Influencing factors of bake hardening value detection of hot-dip galvanized steel sheet

In order to study the influencing factors of bake hardening value detection of hot-dip galvanized steel sheet, the detection method and test results of bake hardening value of HC180BD + Z steel sheet were mainly introduced. The influencing factors of bake hardening value detection such as test temperature, holding time, heating device and tensile pre-strain were analyzed and discussed.The results show that when the same heating device was used, the holding time was controlled to 20 min, and the test temperature rose from 160 ℃ to 180 ℃, the bake hardening value kept an upward trend. However, when the test temperature was 160~170 ℃, the upward trend of bake hardening value was more obvious than that of 170~180 ℃. When the same heating device was used, the test temperature was controlled at 170 ℃. When the holding time was extended from 16 min to 20 min, the bake hardening value increased with the extension of the holding time, but when the holding time was extended from 20 min to 30 min, the bake hardening value did not change significantly. There was no significant difference in the test results of bake hardening value when the same test temperature and holding time were used and different heating devices were used. When the tensile pre-strain increased from 1% to 2%, the change trend of the bake hardening value was synchronized with the tensile pre-strain, and both had an upward trend. When the tensile pre-strain increased from 2% to 3%, the bake hardening value decreased with the increase of the tensile pre-strain.