1、 FORD LABORATORY TEST METHOD BA 003-01 Date Action Revisions 2001 03 02 Revised Editorial no technical change A. P. Cockman 1992 07 17 Printed copies are uncontrolled Page 1 of 2 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF THE SURFACE ROUGHNESS OF COLD ROLLED SHEET STEEL Applicat
2、ion This procedure is used to determine the surface roughness for as-received, cold rolled sheet steel intended for visible exterior painted body panels. The surface roughness of the steel has a large influence on Distinctness of Image after painting. Apparatus Required A tracer (stylus) type surfac
3、e roughness measuring instrument shall be used for all measurements. It shall be capable of measuring both Arithmetic Average (AA or Ra) surface roughness and peak density (Bendix Profilometer Model QHD or equivalent). The instrument and its calibration shall conform to ANSI B46.1-1978 - “Surface Te
4、xture - Surface Roughness, Waviness, and Lay“. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions un
5、less otherwise specified. Procedure 1. Obtain a test sample from the coil which is the full width of the coil and of a convenient length for making surface roughness measurements. The sample shall be taken from the head of the coil but not from the first several wraps to avoid atypical surface condi
6、tion. 2. Wipe the sample with a paper towel to remove surface dirt and/or oil. 3. Mark the sample to divide it into three equal width zones on both sides. (Refer to Figure 1). 4. In each zone on both sides of the sample, measure the AA surface roughness and peak density in the longitudinal (rolling)
7、 direction. Do not make measurements closer than 75 mm to the coil edge. Use a “roughness width cutoff“ of 0.80 mm for the AA roughness measurements, and a threshold of 0.0013 mm for peak density measurements. Record all results. FORD LABORATORY TEST METHOD BA 003-01 Page 2 of 2 Copyright 2001, Ford
8、 Global Technologies, Inc. 5. Repeat Step 4 making measurements in the transverse direction. Record all results. 6. Average the longitudinal and transverse measurements for each of the six zones. Report these average values of AA surface roughness and peak density for each of the six zones. Note: Al
9、l measuring procedures shall conform to ANSI B46.1-1978. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. LOCATION OF TEST SAMPLES L = Longitudinal direction for AA Surface Roughness and Peak Density Checks. T = Transverse direction for AA Surface Roughness and Peak Density Checks. Figure 1
