In the early 1950s, the Soviet Union gave China 1,837 T-34/85 tanks. As of a few years ago, there are at least a hundred of them still in storage and these vehicles appeared to be in good shape (as judged by Chinese military buffs who had come across the storage area without getting arrested).
The T-34 was one of the most successful tank designs of World War II. Over 84,000 were manufactured, 57,000 by the end of the war, and the rest from 1946-58. The first versions had a 76.2mm gun, but all built after 1944 had an 85mm gun. The four man crew also had two 7.62mm machine-guns, one mounted next to the driver in the hull, and the other one on the turret. The 27 ton tank had a top speed of 53 kilometers an hour, which was quite fast for World War II. It's 52mm (2 inch) armor was formidable in 1941, and the T-34 was quite a shock to the invading Germans that encountered it. The T-34/85 led the advance into Germany and Berlin itself in 1945.
Russia exported over 10,000 T-34s, to at least 40 countries. North Korea used them to good effect against U.S. troops in 1950, during the Korean war. American tank crews were startled at how maneuverable and fast the T-34 was.
When the Cold War ended in the early 1990s, at least two dozen nations still had the T-34 in service. The last known combat use of a T-34 was in 1995, when some Bosnian Serbs used one in an attack on UN peacekeepers. There are probably over a thousand T-34s that are still in running condition, or close to it. While inferior in protection and firepower to most modern IFVs (Infantry Fighting Vehicles like the U.S. M-2 Bradley), they can still be useful in keeping civilians in line. Which may be why the Chinese have not melted down all of theirs.