Mechanical Properties of Powder Forged 4100 and 1500 Type Alloy Steels 810243
The use of chromium and manganese as alloying additions to water atomized steels is possible; provided, the manganese and chromium oxides that are formed during the powder production are reduced prior to forging the sintered preform. One way of reducing the chromium and manganese oxides is through the use of high temperature sintering; that is, sintering at temperatures in excess of 1204°C. Utilizing a sintering temperature of either 1260°C or 1315°C, lowers the residual oxygen contents of the 4100 and 1500 type powders to approximately 500 ppm and 400 ppm, respectively. At these low levels of residual oxygen content, the Charpy impact toughness of the chromium-manganese and manganese alloy steels is comparable to the Charpy toughness of the commercially available nickel-molybdenum alloy powder steels. One advantage to the use of high temperature sintering is the ability to shorten the sintering cycle from 30 minutes normally utilized at 1120°C to 5 to 10 minutes at either 1260°C or 1315°C. This shortened sintering time can result in reduced sintering cost. The reduced sintering cost coupled with the lower cost of the chromium and manganese alloying elements result in a significant cost savings when compared to the nickel-molybdenum powder steels.