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A D V A N C E D M A T E R I A L S & P R O C E S S E S | S E P T E M B E R 2 0 2 1 2 0 are also taken on both right-hand and left-hand sides of the housing banjo SN1 and SN2 samples before and after the straightening operation. The test re- sults are given in Table 1. Average val- ues are used to simplify interpretation. The test results show that all the stress values before and after are compressive in nature, but overall magnitude is re- duced after the straightening operation. The compressive residual stress value before straightening is -214 MPa where- as after straightening it is –159 MPa. The drop in compressive residual stress is 25.5%. RESULTS AND DISCUSSION The outcome of x-ray diffraction analysis shows the residual stresses are compressive and are reduced by 25.5% after the straightening operation. The straightening process is unavoidable as it corrects the warpage from the weld- ing process. This reduction in compres- sive residual stress is not a concern for premature part failure or poor perfor- mance because the stress is compres- sive, not tensile. These compressive residual stresses are induced during the shot blasting process which happens at the housing banjo forming stage, to clean the banjo surface from scaling and other debris. It is also understood that the shot blasting produces dim- ples on the banjo surface, which is sim- ilar to shot peening but the magnitude of induced stress is lesser. The induced stress will be on the surface only, not at the subsurface. ~AM&P For more information: Yathish Rao, industry professional, Pune, India, rao. yathish@gmail.com. References 1. Welding, Brazing and Soldering, Vol 6, ASM Handbook, ASM Internation- al, 1993. 2. Surface Engineering, Vol 5, ASM Handbook, ASM International, 1994. 3. Materials Characterization, Vol 10, ASM Handbook, ASM International, 2019. Fig. 2 — Location of residual stress measurements at the brake flange area. MORE CASE STUDIES AND RESIDUAL STRESS TOPICS AT IMAT This article is based on a presentation being given at IMAT 2021 in St. Louis, September 13-16. The author will present this case study as well as others related to the automotive industry. There are also several scheduled talks that discuss residu- al stress. To search for topics and authors at IMAT, visit imatevent.org , view the Technical Program, and search by author, key- words, or browse by topic or day. 2021 INTERNATIONAL MATERIALS, APPLICATIONS & TECHNOLOGIES