ASTM D1662 – Active Sulfur in Cutting Oils
ASTM D1662 Active Sulfur in Cutting Oils – Cutting oils reduce friction and absorb excess heat during metal-working processes. Sulfur in these formulations may be “active” or “inactive”. Active sulfur (often sulfurized fat) provides extreme pressure properties for fluids used in heavy machining operations (such as broaching) or processes involving stainless steel and hard alloys. Inactive sulfur provides milder extreme pressure properties for processes involving brass and aluminum and where active sulfur may cause staining. The choice of formulating with active vs. inactive sulfur should also consider downstream operations and pollution control. This test determines the percent of active sulfur in lubricating oils.
The total sulfur concentration of the sample is determined by x-ray analyses. The sample is heated and copper powder is added incrementally until no active sulfur remains, as demonstrated by no staining on a copper strip immersed in the fluid. The fluid is filtered and an x-ray sulfur determination is made on the fluid with the active sulfur removed. The active sulfur is calculated and reported as percentage in the sample.
The total sulfur concentration of the sample is determined by x-ray analyses. The sample is heated and copper powder is added incrementally until no active sulfur remains, as demonstrated by no staining on a copper strip immersed in the fluid. The fluid is filtered and an x-ray sulfur determination is made on the fluid with the active sulfur removed. The active sulfur is calculated and reported as percentage in the sample.