Heat treatment sharing: How many times can quenching and tempering be repeated?

In the metal heat treatment process,quenching and tempering are two crucial steps,which directly affect the performance and application effect of metal materials.However,the number of times these two steps are repeated is often confusing for beginners.Today,we will discuss in detail the number of repetitions of quenching and tempering.

I.the number of repeatable quenching

Quenching is the process of heating a metal material above a critical temperature and cooling it quickly after holding it for a period of time.This process can transform the structure of the metal material,thereby improving its hardness,wear resistance and strength.However,the quenching process cannot be repeated indefinitely.

According to JIS(Japanese industrial standards),the number of repetitions of quenching(actually quenching operation)is limited to 2 times,including the initial 1 time,for a total of 3 times.This is because multiple quenching can lead to increased deformation of metal materials and even cracking.Especially in the absence of intermediate annealing(or engineering annealing),multiple quenching will gradually change the metal material into a ball shape and eventually crack.Therefore,in order to ensure the performance and quality of metal materials,the number of quenching should be controlled within the specified range.

Of course,if the intermediate annealing is implemented,then the number of repetitions of quenching is not infinite,but relatively more.This is because the intermediate annealing can eliminate the stress and microstructure defects generated during the quenching process,making the metal material less prone to deformation and cracking during the subsequent quenching process.

II.The repeatable number of tempering

Unlike quenching,there is no strict limit to the number of times that tempering can be repeated.Tempering is the process of heating the quenched metal material to a certain temperature and cooling it in a certain way after holding it for a certain time.This process can eliminate the internal stress and brittleness generated during quenching,adjust the mechanical properties of metal materials,stabilize the workpiece size,and improve the cutting performance of certain alloy steels.

Because the tempering process is mainly to eliminate stress and adjust performance,rather than to change the organizational structure of metal materials,the number of repeats of tempering is relatively large.As long as the required hardness or strength requirements are met,the number of tempering can be adjusted according to the specific situation.

III.the combined application of quenching and tempering

In actual production,quenching and tempering are usually applied in combination.Quenching can improve the hardness and strength of metal materials,but it will make the material become brittle;Tempering can eliminate the brittleness and stress caused by quenching,making the material more stable and durable.Therefore,through a reasonable combination of quenching and tempering,metal materials with excellent comprehensive properties can be obtained.

It should be noted that the number of repetitions of quenching and tempering is not the more the better.Excessive quenching times will lead to deformation and cracking of metal materials;Excessive tempering times may cause the metal material to lose its original hardness and strength.Therefore,in the development of heat treatment process,should be based on the type of metal materials,uses and performance requirements,such as a comprehensive consideration of the number of quenching and tempering repetition.

Iv.Summary

In summary,the number of repetitions of quenching and tempering is limited.The number of quenching is limited to 2 times(including the initial 1 time),and the total is 3 times;The number of tempering is relatively large,as long as the required hardness or strength requirements are met.When developing the heat treatment process,the selection of process parameters such as the number of repetitions of quenching and tempering and intermediate annealing should be comprehensively considered according to the specific situation.Through reasonable combination of heat treatment processes,metal material products with excellent comprehensive properties can be obtained.

It is hoped that this sharing can help you better understand the number of repeats of quenching and tempering,and apply it in practical work.If you have any questions or suggestions,please feel free to leave a message!