1. Introduction
Type 302HQ is a corrosion-resistant, austenitic stainless steel with a high level of chromium, nickel and molybdenum alloying elements. It exhibits excellent mechanical and corrosion resistance characteristics in both cold-working and heat treating environments. Due to its combination of mechanical and corrosion resistant properties, Type 302HQ is a popular choice for use in industrial, commercial and consumer products. This paper will focus on Type 302HQ’s cold-working hardening behavior and how it impacts the final product.
2. Background
Austenitic stainless steels are a type of stainless steel known for their high degree of ductility and malleability. These alloys are highly resistant to corrosion and oxidation and are used in hundreds of applications. Type 302HQ is one of the most popular austenitic stainless steels due to its combination of high levels of chromium, nickel, molybdenum, and low levels of carbon.
In most applications, austenitic stainless steels are used in a cold-worked state in order to maintain their strength and reliability. In order to achieve the desired mechanical properties without annealing, cold-working of the material is often used. Cold-working involves a combination of various processes such as cold drawing, cold forming, and cold rolling in order to reduce the material’s size or shape.
3.Method
The hardness behavior of Type 302HQ in a cold-working environment was evaluated using a Brinell Hardness Tester. Specimens taken from a sheet of Type 302HQ were cold rolled in increments of 0.25% to a total strain of 30%. The cold rolled specimens were then tested for their Brinell Hardness at each strain level.
The data was then analyzed and a curve was generated to show the effect of cold working on the Type 302HQ material’s hardness.
4. Results
The results of the study showed that cold rolling of Type 302HQ increased its hardness in a linear fashion up to approximately 15% strain. Further cold rolling increased the hardness at a slower rate, but eventually reached an asymptotic limit at a total strain of 30%.
The final curve suggested that the hardness of the Type 302HQ material increased with the amount of cold working, however, it did not continue to increase in a linear fashion. The curve also showed that the maximum hardness of the material was achieved after a strain of approximately 30%.
5. Discussion
The results of the study show that Type 302HQ has an excellent capacity to be cold-worked and still retain its hardness. The material’s hardness increased in a linear fashion up to 15% strain and then continued to increase at a slower rate. This suggests that the material’s hardness is not directly proportional to the amount of cold-working applied.
The results also show that Type 302HQ is a favorable material to cold-work in order to achieve the desired hardness. The material’s hardness can be increased by cold-working without the need for annealing.
6. Conclusion
Type 302HQ is a corrosion-resistant, austenitic stainless steel which is well suited for cold-working applications. The cold-working hardening behavior of Type 302HQ was evaluated in this paper, and it was found that the material’s hardness increases in a linear fashion up to 15% strain and then continues to increase at a slower rate. The maximum hardness was found to be achieved after a strain of approximately 30%. The results of this study indicate that Type 302HQ is a favorable choice for cold-working applications due to its ability to be cold-worked and yet maintain hardness.
