Improvement of wear resistance of hot working tool steel by hardfacing Part 2 – Case study

Abstract

The performance and service life of the die components are limited because of different reasons such as thermal and mechanical fatigue cracking, wear, plastic deformation, etc. To minimise these damages, the dies are normally subjected to a variety of surface engineering processes. In the present study, the dimensional loss and lifetime of hardfaced and unmodified H11 steel hot forging dies were monitored during service and compared. For this purpose, various experimental tools such as XRD, SEM, optical metallography and microhardness test were employed. Microhardness profiles from surface to the depth of the dies after service were determined to study the variations in mechanical properties. It was observed that the hardfacing with Stellite 21 and Inconel 625 alloys leads to an increase in wear resistance and the working life of the dies in industrial scale. In the case of hardfaced dies, the work hardening of surface produces a self-protecting layer which has a strong metallurgical bonding to the substrate and thus enhances more resistance to further wear, while hardness reduction during service in unmodified H11 steel die causes a reduction in wear resistance and plastic deformation of surface layer.

Effect of Thermal-Cold Cycle on Microstructure and Hardness of a W-Cr-Mn-Mo-V Ferro-based Hardfacing Layer

“…This effect results in the early surface softening and the thermal-cold fatigue damage of the workpiece [1,2]. At present, thermal-cold fatigue damage wearing and the tearing has become one of the main reasons of hot-rollers and scissors failure.…”

A study on the Effects of Geometrical Parameters of Overlay Coated Layer on the Thermal Stress-strain Distributions of Co-based Super-alloy Deposited Layer on Hot-working Tool Steel

“…The overlay coating technology, so called a hardfacing technology, can deposit the super-alloy with excellent wear properties at the elevated temperature on the substrate [3][4][5]. In addition, the metallurgical bonding is created in the vicinity of the joined region between the overlay coated layer and the substrate [3][4][5]. Hence, several engineers related to the development of hot-working tools have paid attention to the application of the overlay coating to the hot-working tools [3][4][5].…”

“…The overlay coating technology, so called a hardfacing technology, can deposit the super-alloy with excellent wear properties at the elevated temperature on the substrate [3][4][5]. In addition, the metallurgical bonding is created in the vicinity of the joined region between the overlay coated layer and the substrate [3][4][5].…”

“…Numerous researchers have endeavoured to improve the wear resistance of the hot-working tools through an overlay coating technology [3][4][5][6][7]. The overlay coating technology, so called a hardfacing technology, can deposit the super-alloy with excellent wear properties at the elevated temperature on the substrate [3][4][5].…”

“…In addition, the metallurgical bonding is created in the vicinity of the joined region between the overlay coated layer and the substrate [3][4][5]. Hence, several engineers related to the development of hot-working tools have paid attention to the application of the overlay coating to the hot-working tools [3][4][5]. Since the metal threedimensional (3D) printing technology has been developed, the interest in the overlay coating technology has greatly increased to extend the service life of hot-working tools through the reduction of an excessive wear of the tool surface [3,6,7].…”