免费av在线-91蜜桃视频-亚洲niry欣赏pics大全-羞羞免费视频-欧美视频在线观看一区-欧美日本在线播放-荡女精品导航-99国产精品免费视频-狠狠一区-在线免费观看www-床戏高潮做进去大尺度视频网站-国产你懂-又黄又湿的免费视频-美女私密视频网站-免费在线观看精品

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.