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Technical Process Introduction

ShapePrecisionPreliminary Background on Deep Drawn Processes
An analysis example of a deep drawn productDie Standardization/ Automated Design

Background information related to Stainless Deep Drawn Process

Martensitic Induced Transformation Process

Austenite phase is formed after the heat solution treatment for the SUS304 and other austenite type stainless steel. However, due to high levels of thermodynamic stability, it is considered to be meta-stable. For example, when SUS304 material is in a cool deep drawn process, energy material is added, creating a more stably organized Martensitic transformation. From the example given, by utilizing cool processing, we are able to achieve the transformation from the Austenite phase to the Martensite phase. This process is referred to as the Martensitic Induced Transformation Process.

(1) Austenite is non-magnetic in nature, however, due to the Martensitic Induced Transformation Process, which creates Martensite, magnetism is obtained.

(2) Martensite is structurally hard compared to Austenite, which can be attributed directly to the number of Martensitic transformation process quantity (higher process quantity = strength increase). However, when the deep drawning process occurs, the Martenitic transformation becomes brittle, causing dangerous duration cracking conditions.

(3) The crystalline structure is presented in the following two ways: Austenite centered cubic lattice face and Martensite centered cubic lattice body. Due to these differences in density between both crystalline structures, a subtle contraction of the product diameter will occur. This subtle contraction is caused during the solid heat-treating solution of the deep drawn product, during the Martensitic transformation process.

Md30(c)Value

Md30(c)Value is used as a parameter for measuring ease of Martensitic Induced Transformation Process.
Md30(c)Value is defined as the temperature where 50% of the structure undergoes a Martensitic transformation and is given a value of 0.3 tensile strain on the Austenite during this single phase.
The larger the value is for the Md30 ()Value, the more unstable Austenite becomes, thus, making it easier to produce Martensite. The Md30 (c) Value relies on various material components and thus, a number of formulas are given.

[Gladman's Formula]
Md30(c) = 497-462(C+N)-9.2(Si)-8.1(Mn)-13.7(Cr)-20(Ni+Cu)-18.5(Mo)

[Nohara's Formula]
Md30(c) = 551-462(C+N)-9.2(Si)-8.1(Mn)-13.7(Cr)-29(Ni+Cu)-18.5(Mo)-68(Nb)-1.42(-8.0)

v:Crystal Grain Size Number