1.Thermal stability
Oxidation resistance
Precision stainless steel parts have excellent oxidation resistance in high temperature environment,which can maintain the stability of their surface and internal structure.This characteristic is mainly due to the addition of alloying elements such as Cr,Al and Si in stainless steel.These elements will form a dense oxide film on the steel surface,such as CrO and AlO.The oxide film can effectively inhibit the generation of a new oxide film and prevent the formed oxide film from being broken,thereby prolonging the service life of the part or improving the bearable service temperature of the part.
Gas medium corrosion resistance
In addition to oxidation resistance,precision stainless steel parts also have good resistance to corrosion by gaseous media.In a variety of high temperature and corrosive gas environment,it can still maintain its own performance stability to ensure the normal operation of the equipment.
II.High temperature strength
Creep strength
Precision stainless steel parts are resistant to slow plastic deformation,known as creep,at high temperatures.Creep strength refers to the maximum stress that a part can withstand in a high temperature environment for a long time at a certain critical creep rate(or critical deformation value in a certain time)in a specific temperature range.This index is very important for evaluating the performance of parts under high temperature and long-term stress conditions.
Endurance strength
Creep rupture strength refers to the critical stress at which a part breaks at a limited temperature and just after a limited time.This strength index reflects the ability of parts to withstand long-term stress in high temperature environment,and is an important parameter to measure the reliability of parts under high temperature service conditions.
High temperature short time strength
The short time strength at high temperature is the strength value measured by placing the specimen in a high temperature environment in the same way as the tensile test at room temperature.This strength value reflects the ability of parts to resist fracture in a short time at high temperature,which is of great significance for evaluating the performance of parts under sudden high temperature or short time high temperature impact conditions.
III.Other heat resistance
Coefficient of thermal expansion
Precision stainless steel parts have a low coefficient of thermal expansion in high temperature environments.This means that when the temperature changes,the size of the part changes relatively little.This feature is extremely beneficial to maintaining the accuracy and stability of the equipment,and can effectively avoid equipment failure or accuracy degradation caused by thermal expansion and contraction of parts.
Thermal conductivity
Although the thermal conductivity of stainless steel is relatively low,its thermal conductivity can meet the heat dissipation requirements in high temperature environment within a certain range.Through reasonable design and application,it can effectively prevent parts from being damaged due to overheating and ensure the normal operation of equipment in high temperature environment.
IV.Influencing factors
Alloy elements
The content of alloying elements such as Cr,Al and Si has a crucial impact on the heat resistance of precision stainless steel parts.In general,as the content of these alloying elements increases,the heat resistance of the part is usually improved.By accurately controlling the proportion of alloy elements,the heat resistance of parts can be optimized to meet the needs of different working conditions.
Heat treatment
The heat resistance of precision stainless steel parts can be further improved by appropriate heat treatment processes,such as solution treatment,aging treatment,etc.Heat treatment process can adjust the structure of the parts,eliminate the internal stress,so as to improve the comprehensive performance of the parts,and make them have better stability and reliability in high temperature environment.
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