This paper discusses the effects of rotational speed of a part on the remelting quality of coating player when surface of the part is treated by using remelting and two -step spray melting method with oxy-acetylene flame self-melting alloy powder.

The results shown that under the same working conditions, the anti-pitting life of spraying weld tappet heated by oxyacetylene flame is longer one-fold and 4-fold compared with 212 built up welding alloy tappet and tufftride Stger tappet treated with 20Cr gas respectively.

This paper analyses the shortcomings of oxyacetylene flame line-material coating technology, gives some measures to overcome them, gets the developed technological parameters by improving the ways of pretreatment and optimizing technological parameters , certifies the realizability of applicating the improved technology by cheek test.

The authors fabricated the flame overlay of tungsten carbide bar by means o f the oxy-acetylene surfacing, introduced the basic characteristics and process of the deposit.