During 40 years from 1960 to 1999, the output of stainless steel was increased from 2.15 million tons to 17.28 million tons, it increased by 8 times.The average growth rate was 5.5 %. The stainless steel is major used for kitchens, home appliance,transport, construction, building and other fields.There are washing chamfer,electric, gas and water heater at the field of kitchen appliance.Home appliance is included of the rotary drum of full-automatic washing machine. At the viewpoint of energy-saving and recycling,the demand of stainless steel is expected to further expand.The transport field is included of exhaust system of railway vehicle and automobile . The quality of stainless steel used for exhaust system is 20-30kgs each car.The annual demand is about 1 million tond in the world.This is the biggest field in stainless steel.At the construction field,the recently demand is rised dramatically. For example,the protective device of subway station in Singapore is used about 5000 tons stainless steel decoration material.After 1980, the stainless steel used for construction is increased by 4 times in Japan. It is used for roof, inside and outside building and structural wood.In 1980s ,at coastal areas of Japan , 304 type non paint material was used as roof material. By consider of antirust ,it translates to use paint stainless steel stepby step.Enter into 1990s,high corrosion-resistance high Cr iron element stainless steel was developed.It was used for roof material, at th meantime ,in order to beautiful,all kinds of surface finishing technique were deceloped.At the building field,dum water sucking tower in Japan used stainless steel.Euramerican cold areas,in order to prevent expressways and bridges from freezing they need to scatter salt , this speeds up corrision of rebar, so they use stainless steel rebar. On the road of North America , during recent 3 years,stainless steel rebars was used in about 40 places.The usage amount was 200-1000 tons each place.Sta