The SL6 was China's most numerous class of steam passenger locomotive and undoubtably one of the most attractive. The Japanese introduced several classes of pacific during their occupation of Manchuria but standardised on the PaShiRo, for volume production. It is thought that 272 were built for the South Manchurian Railway, Manchurian National Railway and the railways of occupied North China between 1933 and 1944. Various Japanese builders, Dalian, Qingdao(Sifang) and the SMRs own workshops were all involved in the construction.

The name "Shengli" or "Victory" was adopted in 1951 for all classes of pacific inherited by the new China and the PaShiRo became the Shengli 6 or SL6. Sifang Works restarted production in 1956 and completed 151 locos before switching to RM construction in 1958.

The pre-liberation machines were numbered SL6 301 to 572 in the 1951 renumbering, with the later Sifang built locos starting at SL6 601. The class were allocated numbers up to 750 in the SL series, with the small class of streamlined SL7s starting at 751. As a result, the 151st and last SL6 was numbered 771. In common with many steam classes, the cabside number often didn't include the suffix, so SL6 631 would have SL631 painted on the loco.

The SL6s saw use in most parts of China and were reported by visitors to centres as far apart as Nanning, Nanjing, Hailaer and Shizuishan. Like the RMs, their inability to haul the heavier passenger trains introduced in the 1970s and 1980s saw them progressively reallocated to secondary duties over the years. By 1990, most of the survivors were concentrated in Manchuria, at Dashiqiao, Jilin and Baicheng depots. At the other end of the country a few remained in use at Chengdu. The final three, SL6 631, 635 and 680 continued in traffic at Jilin until 1991.

As far as is known, none of the SL6s, or any other pacifics, went into industrial or local railway service when their main line careers were over. Only one is known to be preserved, SL6 601 at the Beijing Railway Museum. SL6 724 was set aside at Baotou's Ajila depot for the projected Nei Mongol Railway Museum but hasn't been reported recently. Hopefully it's still in storage somewhere.