Experimental investigation on the spalling failure of a railway turnout made from Hadfield steel

In a rail track structure, turnout is used as transition between straight and branching rails therefore withstands complex dynamic rolling impact loading. This paper reports comprehensive failure investigation of railway off-track made from Hadfield austenitic cast steel. The worn was examined using optical microscopy, scanning electron micro-hardness, quantitative X-ray diffraction analyses. A ball-on-disc sliding wear test also applied to evaluate the work-hardening on property. exhibited surface embrittlement, severe cracking, delamination, spalling characteristics. Severe plastic deformation observed with formation densely packed mechanical twins, which facilitated crack propagation. top developed gradient hardness (HV0.1) profile 8.9 GPa, cracked subsurface 5.9 GPa bulk steel 2 GPa. found have accumulated an extremely high residual compressive stress 500–650 MPa. Strain induced martensite transformation repeatedly evidenced by peak ferritic (110) plane although highly strained nanocrystallised ferrite only detected severely deformed top. Comparative tests showed deteriorated resistance strain-hardened compared