美国免费毛片_亚洲免费播放_毛片网站大全_8x8x打飞机_91福利视频网站_草莓视频成人_69精品丰满人妻无码视频a片_13一16女处被毛片视频_蓝湛被调教嗯啊好深啊_亚洲欧美成人_噜噜在线视频_挪威xxxx性hd极品_口述被爽到呻吟高潮自述_瑟瑟成人网_国产精品久久久久久久一区二区

Stainless steel head due to the inconsistent surface and center cooling rate and time, the occurrence of thermal stress. Stainless steel head the workpiece surface pressure and heart Ministry tension under the action of thermal stress. This phenomenon is cooled velocity, material composition and heat treatment and other factors.

 

Stainless steel during heat treatment due to the change in the organization that is the transformation of austenite to martensite, accompanied by an increase in specific volume expansion in volume of the workpiece, the various parts of the workpiece has a phase change, causing the volume grew inconsistency of the stress.

 

The end result stainless steel head the surface tissue stress is tensile stress, the heart portion compressive stress, and thermal stress exactly the opposite. The stress in the workpiece size and cooling rate of martensite transformation zone factor, shape, chemical composition of the material.

 

Thermal stress before organizational changes it has produced a stainless steel head, and the stress is generated in the organizational transformation process, the entire cooling process, heat stress and the results of the stress combined effects, that is, the work actually present stress . The results of these two combined effects of stress is very complex, being affected by many factors, such as composition, shape, heat treatment and so on. Only two types, namely thermal stress and stress, the role of the opposite direction when the two offset its development process, the role of the same direction both mutual superposition.