Laboratory for Multiphysics & Multiscale Systems [2014 Fall Creative Capstone Design] Kwon, Jaehwan Kim, Junhyung Hyun, Seunghyeop Kwon, Soonhyun

1.Introduction 1.1 Importance of Hardness 1.2 To measure hardness 1.3 Limitation of Destructive Test 2. Theoretical Background 2.1 Phase 2.2 Hardening 3. Experiment Design 3.1 Objective of experiment 3.2 Define experiment data 4. Results and discussion 4.1 Results 4.2 Discussion 5. Conclusion 6. Reference 7. Appendix 7.1 Specification of ultrasonic tester 2

1. Introduction Importance of Hardness Hardness guarantees to prevent (1) Crack (2) Chip which is related to life of product Crack causes (1)stress concentration (2)reduce the life Proper hardness should be guaranteed in manufacturing Chip causes (1)debris (2)disturb the motion

1. Introduction To measure hardness Hardness is quantified by the shape of indentation Indent is to press the surface of material with tip Hardness tester In this way, however, we should destruct the sample to conduct the test

1. Introduction Benefit of Non-Destructive testing To overcome the limitation of destructive test, we selected non-destructive test as a solution Non-destructive sugar content tester 1) Can use the product after testing 2) Can test every product 3) Can test working product Non-destructive testing in boiler tube

2. Theoretical background Phase Phase is a homogeneous portion of a system that has uniform physical and chemical characteristics Phase transition makes hardness different in same sample [phase 1] [phase 2] Phase3 Phase 2 Phase 1 Steel Joint welding

2. Theoretical background Transformation Hardening Transformation hardening is causing phase transition to make material harder e.g) heat treatment In steel, After heat treatment much harder in heat treated area less hard in matrix (base material)

3. Experiment Design 8 We want to figure out the relation b/w the depth from ultrasonic test and hardness information in hardened area 3.1 Objective of experiment

3. Experiment Design 9 (1)Ultrasonic depth Depth from Ultrasonic tester We measure three depths from three different source We selected three source to measure depth 3.2 Define experiment data (3) Visual depth Depth from color difference (2) Hardened depth Point where Δ Hv>70Hv from hardness tester Depth = 0.7 mm Hardened zone (HV) (mm) * HV = Vickers hardness [Hardness results]

Results Hardened depth, visual depth, Ultrasonic depth Three depths are almost same ! Depth(mm) Specimen #

Results #1visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.0 mm 2.2 mm7.3%9.1%0.2 mm Part21.7 mm1.6 mm1.7 mm0.2%3.0%0.0 mm Part32.2 mm2.1 mm2.3 mm3.3%8.7%0.2 mm Part42.0 mm1.9 mm1.8 mm10.0%5.6%0.2 mm Part52.4 mm2.5 mm2.2 mm9.3%13.6%0.3 mm Part61.5 mm 1.7 mm10.3%11.8%0.2 mm Part72.5 mm2.4 mm 4.2%0.0%0.1 mm Part81.5 mm1.6 mm1.5 mm1.3%6.7%0.1 mm Part92.2 mm2.1 mm2.0 mm11.3%5.0%0.2 mm

Results #2visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.4 mm2.2 mm2.3 mm2.5%4.3%0.1 mm Part21.8 mm1.9 mm 4.5%2.7%0.1 mm Part32.3 mm2.4 mm2.2 mm6.0%9.1%0.2 mm Part41.9 mm2.0 mm1.7 mm10.2%17.6%0.3 mm Part52.4 mm 2.3 mm3.1%4.3%0.1 mm Part61.7 mm 2.3%0.0%0.0 mm Part72.6 mm 2.4 mm7.2%8.3%0.2 mm Part81.7 mm1.6 mm1.5 mm10.0%6.7%0.2 mm Part92.3 mm 2.2 mm6.6%4.5%0.1 mm

Results #1visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.0 mm 2.2 mm7.3%9.1%0.2 mm Part21.7 mm1.6 mm1.7 mm0.2%3.0%0.0 mm Part32.2 mm2.1 mm2.3 mm3.3%8.7%0.2 mm Part42.0 mm1.9 mm1.8 mm10.0%5.6%0.2 mm Part52.4 mm2.5 mm2.2 mm9.3%13.6%0.3 mm Part61.5 mm 1.7 mm10.3%11.8%0.2 mm Part72.5 mm2.4 mm 4.2%0.0%0.1 mm Part81.5 mm1.6 mm1.5 mm1.3%6.7%0.1 mm Part92.2 mm2.1 mm2.0 mm11.3%5.0%0.2 mm

Results #3visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.3 mm 2.2 mm6.3%4.5%0.1 mm Part21.7 mm1.8 mm 5.2%0.0%0.1 mm Part32.3 mm2.4 mm2.2 mm4.5%9.1%0.2 mm Part41.8 mm1.9 mm1.7 mm5.2%11.8%0.2 mm Part52.5 mm2.3 mm 7.4%0.0%0.2 mm Part61.6 mm1.7 mm 4.3%0.0%0.1 mm Part72.6 mm 2.4 mm6.7%8.3%0.2 mm Part81.8 mm1.7 mm1.5 mm18.1%13.3%0.3 mm Part92.2 mm2.1 mm 4.0%0.0%0.1 mm

Results #4visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.3 mm 1.6%0.0%0.0 mm Part21.8 mm1.6 mm1.7 mm5.4%5.9%0.1 mm Part32.3 mm2.4 mm2.2 mm3.9%9.1%0.2 mm Part41.7 mm 1.5 mm13.0%13.3%0.2 mm Part52.4 mm 2.2 mm7.9%9.1%0.2 mm Part61.6 mm1.5 mm1.7 mm4.3%11.8%0.2 mm Part72.6 mm 2.5 mm2.5%4.0%0.1 mm Part81.6 mm1.5 mm1.6 mm2.8%6.3%0.1 mm Part92.2 mm2.3 mm2.1 mm5.7%9.5%0.2 mm

Results #5visual depthultrasonic depthhardened depthvisual depth errorultrasonic depth errorMaximum error value Part12.3 mm2.2 mm 3.9%0.0%0.1 mm Part21.7 mm 1.6 mm4.7%6.2%0.1 mm Part32.3 mm2.4 mm2.1 mm8.3%14.3%0.3 mm Part41.7 mm1.8 mm1.6 mm7.0%12.5%0.2 mm Part52.4 mm2.5 mm2.3 mm3.0%8.7%0.2 mm Part61.8 mm1.7 mm1.6 mm13.6%6.2%0.2 mm Part72.6 mm 2.4 mm8.9%8.3%0.2 mm Part81.7 mm 1.5 mm14.3%13.3%0.2 mm Part92.2 mm 2.0 mm11.3%10.0%0.2 mm

17 Specimen # Δ Hv≥70 ( a ) Visual depth ( b ) Ultrasonic depth ( c ) deviation a-b a-c b-c )deviation of (a-b) and (a-c) have similar value 2)(c-0.1) is almost same with (a) 4.2 Discussion [unit: mm]

5. Conclusion 18 (1) We can know hardened depth from ultrasonic test without cutting the sample. (2) Also, we confirmed that martensitic hardness is guaranteed from surface to ultrasonic depth From experiment, Ultrasonic depth ≈ Hardened depth ≈ Visual depth

6. Reference Roux, A., et al. Tensile response of the muscle-tendon complex using discrete element model. Computer Methods in Biomechanics and Biomedical Engineering, 2014, Vol.17, No. S1, Maria A., et al. Model for Vickers microhardness prediction applied to SnO2 and TiO2 in the normal and high pressure phases. Journal of the European Ceramic Society, 2014, Vol.34, Issue 15, Aude P., et al, Towards a real time release approach for manufacturing tablets using NIR spectroscopy, Journal of Pharmaceutical and Biomedical Analysis, 2014, Vol. 98, Xiangjun Chen, et al, The finite element analysis of austenite decomposition during continuous cooling in 22MnB5 steel, Modeling and Simulation in Materials Science and Engineering, 2014, Vol.22, Number 6 GRUM, Janez. A review of the influence of grinding conditions on resulting residual stresses after induction surface hardening and grinding. Journal of Materials Processing Technology, 2001, 114.3:

Specification of Ultrasonic tester

Q & A 21