Innovation in producing crane rail fishplate using Fe–Mn–Si–Cr based shape memory alloy

Abstract

An Fe–Mn–Si–Cr shape memory alloy is applied to make crane rail fishplates. The shape recovery of the reverse martensite transformation from hcp to fcc is utilised to connect finite lengths of rail. Rails connected by normal steel fishplates gradually become separated at the joint and can be damaged by broken flakes in the gap and dents during heavy duty operation of the crane. To eliminate such problems, a sufficient and controlled compressive stress is required at the joint to resist the stress responsible for creating the gap. A quantitative estimate of the load required to separate the joint has been made to calibrate the compressive stress yielded by the reverse martensite transformation of fishplates. An innovative joining technique that ensures adequate and controlled compressive stress at the joined parts has been developed using a Fe–Mn–Si–Cr shape memory alloy together with sophisticated materials design and installation techniques.

Design of Devices and Manufacturing of Fe-Mn-Si Shape Memory Alloy Couplings

“…Seamless and welded couplings were already developed in China and Japan. These results are documented and summarized by Otsuka and Wayman (1998), Dunne (2012), Awaji (2008), Maruyama (1993Maruyama ( , 2008, W. Liu (1999), D.Z. Liu (1997), Hiroshi (2006), and Kajiwara (2003).…”

Design Concept and Applications of Fe–Mn–Si-Based Alloys—from Shape-Memory to Seismic Response Control

“…The mechanism for generating the recovery stress is discussed in the literature, 2,57) which can be summarized as follows. On heating, the shape recovery contraction strain cancels thermal expansion of the objects and shape-memory devices themselves, and the reverse transformation continuing after contacting of the objects produces an elastic stress.…”

Comparison of Reverse Transformation Behaviors of Thermally- and Deformation-Induced ε-Martensite in Fe-28Mn-6Si-5Cr Shape Memory Alloy

“…The shape memory effect is associated with deformation-induced martensitic transformation and its reverse transformation from ε-martensite to γ-austenite on subsequent heating 1) . The Fe-Mn-Si alloys are applied to connecting devices, such as pipe joints and crane-rail sh plates 2) , utilizing its shape recovery force. An alternative application of Fe-Mn-Si alloys 3) as seismic damper for buildings has attracted much attention lately due to the superior low-cycle fatigue properties associated with the reversible γ↔ε transformation under push-pull loading 4) .…”