Between 1956 and 1960, various factories in China manufactured a total of 42 prototypes of a new 2-10-2 freight locomotive, which was based on the Soviet ОР21. From 1964 onwards, series production of a total of 4,675 additional machines, which were soon referred to as QJ, began in Datong. The abbreviation here stood for “Qianjin”, which means “progress”.

They replaced the JF and FD in heavy freight service and also pulled heavy passenger trains. In addition to the stoker and mostly smoke deflectors, their features also included the distinctive air horn. Some QJs were also built in Soviet broad gauge. A chimney similar to the Giesl ejector was tested on other machines.

Although production continued until 1988, replacement with diesel locomotives began in the eighties. After steam operations on the Chinese State Railways officially ended in 2002, the last of them disappeared from the main lines in 2003. However, the private JiTong Railway used the QJ to transport coal on its 945 km long line in Inner Mongolia until 2005 and it was also used by industrial companies until around 2010. Three QJs later found their way to the USA.