Low temperature fracture mechanics and testing for 410 SS

Overview

John Crane is a global leader in providing mission-critical technologies and services to process industries. The wish is to determine whether or not they can extend the service life of their 410 stainless stress (SS) components below the -40°C limit without catastrophic failure. Fracture toughness of the metal samples will be tested with a Charpy Impact Tester and fracture surfaces will be analyzed through SEM micrographs.

Objectives

The objective of this project is to analyze the failure mechanics of 410 SS. It is the group’s goal to understand how temperature, bar stock size, and orientation of the sample impacts the performance of the material and how it will affect future applications.

Approach

-Meet with our sponsor to understand the applications of the material and their desired outcome

-Review ASTM E23 standard to understand how the Charpy Impact test is conducted

-Research safest and most effective recipe for cooling bath

-Model samples in accordance with ASTM E23 Type ACF (10x10x55) to give to manufacture

-Manufacture samples from 410 SS bar stock in longitudinal and vertical directions

-Meet with faculty in charge of Charpy impact machine to go over logistics and safety

-Get trained on SEM to have access to the machine for future analysis

-Conduct Charpy test and record respective impact energies reported by machine

-Take micrographs of fracture surface to analyze any ductile or brittle fracture regions

Outcomes

-An in-depth excel document with the impact energies recorded from each of the samples

-Optical images of the fracture surfaces of samples

-SEM images of various zones on fracture surfaces

-Crack initiation zone

-Crack propagation zone

-Shear fracture zone

-Official recommendation on the temperatures 410 SS can withstand

-John crane will be able to reevaluate their applications for their 410 SS products

-John Crane will have more data to justify safety protocols in their products