Failure analysis of railway brake blocks

✍ Scribed by John Ade Ajayi; O.A. Adeleke

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 426 KB
• Volume: 4
• Category: Article
• ISSN: 1350-6307
• DOI: 10.1016/s1350-6307(97)00012-5

✦ Synopsis

Past efforts of the Nigerian Railway Corporation to produce shoe brake blocks locally have proved unsuccessful; the brake blocks produced are defective, and are highly susceptible to brittle (catastrophic) failure. The objective of this work was to undertake failure analysis of locally produced shoe blocks, and to design a metallurgical process to produce efficient ones. To this end, mechanical and microstructural analyses of samples of the standard, failed and cast shoe blocks were carried out. The result of the investigations reveals that the standard brake block is nodular (graphitic) cast-iron, the failed block is cast-iron with combined carbon (cementite), and the cast block is cast-iron with graphite flakes. The cast block can be upgraded to the standard through appropriate inoculation of the melt if permanent mould casting facilities have to be employed.