Round Specimens - CMS uses the ASTM E8 standard dimensions when preparing a specimen for testing. The dimensions are determined by size of material submitted. The largest size bar possible should be machined for testing for optimal results. Round specimens are machined using a lathe. The bars should be machined to size using feeds and speeds best dictated by cutting tools being used an experience with the materials or conditions. Standard round specimens are governed by ASTM E8, A370, B557, or F606.
Specimen machining shall be prepared in accordance with ASTM E23. Specimens machined by CMS use the dimensions dictated by ASTM E23 Fig 6 Type A, which is a standard size bar.
Hydrogen Embrittlement Testing is preformed in accordance with ASTM-F-519. CMS does sell these specialized test bars in a set of five. Typical processing involves plating 4 of the sample, the last sample is non-plated but still subjected to the relief process. Typical relief process is 350 F for 4 hours. The non-plated sample is tensile tested for ultimate strength. The four plated samples are held at 75% of the strength recorded on the tensile tested sample. The samples are held for 200 hours in order to certify relief process has diffused hydrogen from structure.
Plate Specimens - This specimen is used for testing metallic materials in the form of plate, shapes, and flat material having a nominal thickness of 3/16 inch or over. These specimens will be cut with the band saw or horizontal saw, depending on thickness, to approximate size. The finished dimensions will be attained by using belt sander for proper size. Care must be taken to avoid overheating during sanding. Figure 1 of this document shows the proper dimensions for flat specimens.
Sheet Specimens – This specimen is used for testing metallic materials in the form of sheet, plate, flat wire, strip, band, hoop, rectangles, and shapes ranging in nominal thickness from .005 to 5/8 inch. These specimens will be cut with the band saw of horizontal saw depending on thickness to approximate size. The finished dimensions will be attained by using belt sander for proper dimensions. Care must be taken to avoid overheating during sanding. Figure 1 of this document shows the proper dimensions for flat specimens.
Bend testing shall be performed in accordance with ASTM E290, unless otherwise specified by client. This procedure may be deviated from at the client's request. In this event the procedure or method that was used shall be notedon the Lab worksheet.
Various devices are suitable for bending. CMS uses Arrangement A and C of ASTM E290.
Colorado Metallurgical Services has several band saws, abrasive cutoff saws, plasma cutting, and precision diamond saws which enable us to section a material. CMS most often utilizes this department for sectioning out test specimens for testing. It also aids our Metallurgical department for extracting specific areas of interest during a failure investigation.