The present paper reviews systematically the process of the development on thehigh hot-strength hot-work die steels in recent years in China,discusses the improvement on their heat treatment technique,and suggests that developing new type of steel,raising metallurgical and forged quality, improving heat treatment technique and theirorganic combining are the keys to lengthen die life.

Research and Application of High Strength Hot Work Die Steel in China;

Exploitation of New-style Hot Work Die Steel 4Cr2MoWVNi and Its Applicable Studies of Cummins Connecting Rod Dies;

According to the service conditions of hot work die steels,six kinds of steels were designed based on uniform design method,as well as the heat treatment processes.

Microstructure simulation in hot die steel after hot forging and simulation software design;

Laser cladding Stellite X-40 Co-based alloy on hot die steel;

Research status and development trends of thermal fatigue property of hot die steels;

Introduced the working conditions and hot spray-welding coat design of hot-working die steel, and designed the hot spray-welding process, at last analyzed hot spray-welding coat element and its performance.

The importance of the hot-working die steel in the production is pointed.

For this reason,the chromium content was decreased,the molybdnum and vanadium contents incrcased and the tungsten added in the hot-working die steel so as to improve on its overall property.