High-carbon steel: microstructure and abrasive wear resistance of heat affected zone after welding with fast cooling

M Osipov,V Efremenko,Prjsc “Zaporozhtransformator" ,National University ,M Brykov,Zaporizhzhya Polytechnic" ,A Kapustyan,T Akrytova,"Zaporizhzhya Polytechnic" National University ,Yu Kalinin,Priazovskyi State Technical University

doi:10.31891/2079-1372-2021-99-1-59-65

Abstract

The goal of this work is to estimate the abrasive wear resistance of heat affected zone (HAZ) after welding high-carbon low-alloy steel 120Mn3Si2 with fast cooling. The following benchmark data were used: microstructures of HAZ of 120Mn3Si2 steel after welding with cooling in water; abrasive wear resistance of different microstructure constituents of 120Mn3Si2 steel in two-body abrasive wear conditions. It is shown that high abrasive wear resistance of material in HAZ is provided in the vicinity of fusion line. The reason is unstable retained austenite which appears in HAZ as a result of quenching at fast cooling right after welding. The wear resistance of material in HAZ is altered by microstructural changes from austenite to austenite+martensite and finally martensite. The martensitic zone is about 0.5 mm wide and it is followed by zone of tempering of initial structure of steel. Zone of tempering is 1.5-2.0 mm wide and is the only zone of low abrasive wear resistance in HAZ of 120Mn3Si2 steel welded with fast cooling. Welding of 120Mn3Si2 steel with fast cooling in water results in welding joints which have as high wear resistant as the base material or even higher. This enables manufacturing flat welded elements with high wear-resistance and large surface area

Highlights

Protection against abrasive and other kinds of wear requires materials with specific properties
The martensitic layer appears after quenching in the near surface regions where significant decarburization had happened [22]. 5 mm thick plates of 120Mn3Si2 steel where quenched from 900 oC, held isothermally at 250 oC and were welded with fast cooling in water
The microstructure of welding joint from 120Mn3Si2 side is shown on Fig.1, a

Summary

Introduction

Protection against abrasive and other kinds of wear requires materials with specific properties. The problem may arise if such thermally treated machine parts are to be welded. Heat input during thermal welding cycle changes the initial wear resistant microstructure inside heat affected zone (HAZ). Special efforts are needed to minimize HAZ and provide quality welding joints while welding heat treated high-carbon wear resistant steels. If two plates of high-carbon steel are welded, a zone of changed wear resistance appears to be 10 mm wide. It is necessary to know the wear resistance of this zone because local low wear resistance may negatively affect the overall lifetime of machine part. In this study the attempt is made to estimate the abrasive wear resistance in HAZ of high-carbon low-alloy steel 120Mn3Si2 after welding with fast cooling

Objectives

Methods

Results

Conclusion