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Failure analysis of hanger for superheater tube
Ardy H.a, Bangun D.A.a, Wibowo A.a
a Materials Science and Engineering Research Group, Bandung Institute of Technology, Bandung, 40132, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© 2020 American Institute of Physics Inc.. All rights reserved.Seven out of 12 pieces of hangers for superheater pipe were failed after one year in service. Failure analysis has been conducted to find out the root cause of failure. Hanger material is ASTM A182 Grade F22 Class 1. Fractography examinations revealed that the fracture mode is due to mechanical fatigue. Tensile test results show a tensile strength of 1015 MPa which is far beyond the minimum standard requirement of 415 MPa. The hardness of the failed hanger is between 270 to 325 HB, and un-failed hanger is around 245 HB, which are higher than the maximum standard requirement of 170 HB. The Charpy impact energy is 3 J, far below the standard requirement of 54 J. The microstructure in the bend area and the straight section contained tempered martensite and ferrite. Further examinations were conducted by heat treatment simulations to explore properties after heat treatment. Materials are subjected to full annealing treatment at 900°C, and normalizing at 955°C followed by tempering at 675°C. The average hardness is 154 HB after annealing, and 235 HB after normalizing and tempering. According to heat treatment simulation results, hanger material was supposed to be supplied under annealing condition where the hardness fulfils the standard requirement. Failure of superheater pipe hanger is due to improper heat treatment which promote brittleness and initiate premature crack during start-up. Crack initiation might also occur during post forging quenching. Fatigue crack propagation occur during service by small amplitude vibration.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1063/5.0017604[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]