CONTROLLED COOLING: Process by which steel is cooled from an elevated temperature in a predetermined manner to avoid excessive hardening, cracking or internal damage.
强制冷却：将高温钢材强制冷却到设计温度的工序，可防止钢材硬化过度，破裂或者内部损伤。
2
Because of the fast cooling of flowing medium, the hydrogen cracking occurs easily under in-service welding.
在役焊接过程中，管内流动介质的快速冷却，易使接头出现氢致裂纹。
3
Also a closing course of initial crack and thermal cracking coming into being in the cooling process are observed in our experiment.