I was looking over some threads and came across a topic that might be good to discuss.
Some posts recently led me to believe that there are some new comers who believe that quenching steel faster will lead to a higher hardness and that even something like 1018 low carbon steel could be reach adequate hardness with a fast enough quench.
While an adequate quenching speed is certainly important, the carbon content of the steel will determine the maximum as-quenched hardness. Hardness increases steadily up to about 0.8% carbon then levels off and actually can decrease due to excessive retained austenite. So, for a refresher to the old members and clarification to new members, quenching speed just needs to be adequate to reach full hardness, and faster quenching won't help if maximum hardness has been reached for the available carbon.
Some posts recently led me to believe that there are some new comers who believe that quenching steel faster will lead to a higher hardness and that even something like 1018 low carbon steel could be reach adequate hardness with a fast enough quench.
While an adequate quenching speed is certainly important, the carbon content of the steel will determine the maximum as-quenched hardness. Hardness increases steadily up to about 0.8% carbon then levels off and actually can decrease due to excessive retained austenite. So, for a refresher to the old members and clarification to new members, quenching speed just needs to be adequate to reach full hardness, and faster quenching won't help if maximum hardness has been reached for the available carbon.