SAE J1993:2019 pdf free

SAE J1993:2019 pdf free.High-Carbon Cast-Steel Grit
Microstructure一The microstructure of high-carbon cast-steel grit shall consist of martensite, tempered to a degree consistent with the hardness, with fine, well distributed carbides, if any. Some retained austenite may be observed in H hardness grit.
General Appearance – The cast-steel grit shall be as angular as commercially possible. A total of no more than 40% of the grit particles shall have objectionable characteristics or contain more than 1% by weight of nonmetallic material. Any one particle tested that has more than one objectionable characteristic will only be counted once in the total. Notwithstanding the allowable percentages listed as follows, no more than a total of 40% objectionable particles are allowed.
PARTICLE SHAPE- For the hard steel grits, HCS G(1)L, HCS G(1)H, there shall be no more than 5% round or half round particles. For the soft steel grits, HCS G(1)S and HCS G(1)M, there shall be no more than 10% round or half round particles.
SHRINKAGE – No more than 10% of the particles in the sample shall contain shrinkage. Shrinkage is an internal cavity with irregular dendritic surface, greater in area than 40% of the pellet area.
CRACKS- -No more than 40% of the particles examined shall contain major cracks. A major crack is defined as a linear discontinuity whose length is greater than three times its width and is radial in direction.
MICROSTRUCTURE一Carbide networks, grain boundary segregation, decarburization, and high-temperature transformation products such as pearlite are undesirable. No more than 15% of the particles tested shall contain these defects.
Hardness Testing一Hardness measurements shall be taken on any sound area of a particle, preferably halfway between the center and the edge, on a minimum of ten particles in the mounted specimen. The hardness shall be determined in accordance with ASTM E 384 or equivalent microhardness testing methods.
For G-80 and smaller grit, a load of 100 g shall be used. For G-50 and G-40, grit a load of 500 g shall be used.For grit larger than G-40, the load may be either 500 or 1000 g. Conversion to approximate Rockwell C numbers may be obtained from ASTM E 140 and manufacturers of hardness testers.SAE J1993 pdf free download.