Microstructure and Heat Treatment of Hot Work Tool Steel: Influence on Mechanical Properties and Wear Behaviour

2018 ◽  
Vol 767 ◽  
pp. 196-203 ◽  
Author(s):  
Božo Skela ◽  
Marko Sedlaček ◽  
Bojan Podgornik
Keyword(s):  
Tensile Strength ◽  
Impact Toughness ◽  
Abrasive Wear ◽  
Tool Steel ◽  
Wear Behaviour ◽  
Wear Properties ◽  
Tempering Temperature ◽  
Hot Work Tool Steel ◽  
Heat Treated ◽  
Wear Tests

Good mechanical and wear properties of hot-work tool steels are needed for tools to withstand severe service conditions during their operational lifetime. Thus, the aim of this investigation was to correlate mechanical and wear properties with changes in microstructure of commercially available hot work tool steel Sitherm S361R. Hardness, impact toughness, tensile strength and wear tests were performed. Hot-work tool steel was heat treated at austenitizing temperature 1030 °C for 15 min in a horizontal vacuum furnace and gas quenched using nitrogen. One set of samples was investigated in as quenched state. Double tempering of samples was performed after quenching for 2 h at each of chosen temperatures, with first tempering temperature of 500 °C for the whole set of tempered samples. The second tempering was conducted at temperatures from 520 °C to 640 °C with increment of 30 °C for each set of samples. Microstructure of differently heat treated samples showed martensitic matrix, but different fraction and distribution of carbides, consequently influencing hardness, impact toughness, tensile strength, yield strength and wear resistance. Reciprocating sliding wear tests were carried out at room temperature in order to correlate microstructure of differently heat treated hot-work tool steel with wear. In order to achieve adhesive and abrasive wear mechanisms, 100Cr6 and Al2O3 balls were used as counter-body, respectively. Combination of adhesive and abrasive wear was observed for all specimens with different hardness when using 100Cr6 material as a counter body. However, in the case of Al2O3 abrasive wear was found as the prevailing wear mechanism.

Wear behaviour and correlations to the microstructural characteristics of heat treated hot work tool steel

Wear ◽  
2019 ◽  
Vol 426-427 ◽  
pp. 1118-1128 ◽  
Author(s):  
Božo Skela ◽  
Marko Sedlaček ◽  
Fevzi Kafexhiu ◽  
Bojan Podgornik
Keyword(s):  
Tool Steel ◽  
Wear Behaviour ◽  
Microstructural Characteristics ◽  
Hot Work Tool Steel ◽  
Heat Treated

Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3077-3089
Author(s):  
Alexeis Sánchez ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
I. Mejía
Keyword(s):  
Heat Treatment ◽  
Abrasive Wear ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Wear Behaviour ◽  
White Iron ◽  
Heat Treated ◽  
Bulk Hardness ◽  
Abrasive Wear Behavior ◽  
Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

LSS H11

Alloy Digest ◽  
2009 ◽  
Vol 58 (2) ◽  
Keyword(s):  
Wear Resistance ◽  
Impact Toughness ◽  
Physical Properties ◽  
Tool Steel ◽  
Heat Treating ◽  
Steel Company ◽  
Hot Work Tool Steel ◽  
Specialty Steel

Abstract LSS H11 is a hot-work tool steel with excellent impact toughness. It is used where resistance to cracking is needed. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on wear resistance as well as heat treating and machining. Filing Code: TS-677. Producer or source: Latrobe Specialty Steel Company.

Microstructural Characterization of Ledeburitic Tool Steel after Sub-Zero Treatment and Tempering

2020 ◽  
Vol 403 ◽  
pp. 103-109
Author(s):  
Jana Ptačinová ◽  
Juraj Ďurica ◽  
Matej Pašák ◽  
Martin Kusy ◽  
Peter Jurči
Keyword(s):  
Population Density ◽  
Tool Steel ◽  
Retained Austenite ◽  
Microstructural Characterization ◽  
Vacuum Furnace ◽  
Nitrogen Gas ◽  
Tempering Temperature ◽  
Heat Treated ◽  
Gas Quenching

Microstructural characterization of ledeburitic tool steel Vanadis 6 after sub-zero treatment and tempering has been examined. The samples were heat treated using following schedules: heating to the austenitizing temperature (TA = 1050 °C) in a vacuum furnace, hold at the final temperature for 30 min. and nitrogen gas quenching (5 bar). The sub-zero treatments consisted of immediate (after quenching) immersion of the material into the liquid helium (-269 °C), hold at the soaking temperature and removal the samples to be heated to a room temperature. Double tempering has been performed at the temperatures from the range 170 – 530 °C, whereas each tempering cycle was realized with a hold of 2 h. Typical heat treated microstructure of ledeburitic steels consists, besides of the martensitic matrix with certain amount of retained austenite, of several types of carbides – eutectic, secondary and small globular carbides. In sub-zero treated steel the amount of retained austenite is significantly reduced. The population density of small globular carbides increase as a result of sub-zero treating. Tempering of the material resulted in decrease in population density of small globular carbides with increasing the tempering temperature. The hardness of sub-zero treated material is higher than that of conventionally quenched one. Also, this tendency is preserved when the steel is low-temperature tempered. On the other hand, the hardness of conventionally quenched steel becomes higher than that of SZT one when tempered at the temperature of secondary hardening.

Oscillating Contact Wear in Cold Sprayed Ti6Al4V Coatings for Aeronautical Repairs

2018 ◽  
Vol 941 ◽  
pp. 1686-1691 ◽  
Author(s):  
Pedro Poza ◽  
Paloma Sirvent ◽  
Álvaro Rico ◽  
Claudio J. Múnez ◽  
Miguel Ángel Garrido
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
Point Of View ◽  
Wear Behaviour ◽  
Bulk Alloy ◽  
Contact Wear ◽  
Heat Treated ◽  
Mixed Layers ◽  
Wear Tests ◽  
Mixed Mechanism

Ti6Al4V coatings were cold sprayed onto the same bulk alloy using standard conditions and a set of parameters developed to improve the coating’s performance. In addition, the enhanced coating was heat treated to improve coating adhesion and reduce porosity. Wear tests were performed, onto the coatings and the substrate, in oscillating conditions, which simulate wear induced by the contact with bearing parts during vibration. Wear behaviour at room temperature is dominated by a mixed mechanism, which involves plastic deformation and transference from the counterbody forming mechanically mixed layers. As temperature is increased, the formation of mechanically mixed layers dominates wear. The wear resistance of the enhanced coatings is similar to the bulk alloy, or even better in some conditions. Consequently, cold sprayed improved coatings could be used for repairing titanium components from the contact wear point of view.

Influence of loading conditions on wear behaviour of H11 tool steel

2019 ◽  
Vol 16 (5) ◽  
pp. 614-624 ◽  
Author(s):  
Sam Joshy ◽  
Jayadevan K.R. ◽  
Ramesh A. ◽  
Mahipal D.
Keyword(s):  
Plastic Deformation ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Tool Steel ◽  
Frictional Force ◽  
Normal Load ◽  
Hot Forging ◽  
Surface Hardness ◽  
Wear Behaviour ◽  
Content Type

Purpose In hot forging, a significant amount of forging force is used for overcoming frictional force at the die-billet interface. The high frictional force along with thermomechanical stress lead to wear, plastic deformation, mechanical fatigue and cracks, which reduce the service life of hot forging dies. Of all these different types of issues, wear is the predominant mode of failure in hot forging dies. This paper aims to describe mechanisms of wear transition in different loads at near forging temperature, occurring during sliding of chromium-based H11 tool steel specimens. Design/methodology/approach High temperature pin-on-disc tests are performed with pin specimens machined from bars of X38CrMoV5 steel, heat treated to surface hardness of 40-42 HRc. The disc is made of EN 31 steel with hardness of 60-62 HRc. Tests are performed at constant temperature of 500°C, and the normal load was varied from 20 to 70 N. Findings Scanning electron microscopy investigations on worn surface have revealed that wear is primarily due to abrasion and plastic deformation. The test results show an increasing trend in wear rate with increase in load up to 30 N, followed by a reversal in trend until 50 N. This transition in wear rate is caused by development of wear resistant layers, which are formed by compaction of wear debris particles on to the worn surfaces. These compact layers are found to be stable during load range from 40 and 50 N. However, with further increase in load, abrasive wear tracks are observed without any evidence of protective layers. As a result, there is an increase in wear rate with increase in loads above 50 N. In addition, plastic shearing was dominant over abrasive wear at this load regime. Originality/value The study on wear behaviour of H11 hot forging steel at 20 to 70 N will be an input to the research in hot forming industries.

scholarly journals The Effect of Tempering on the Microstructure and Mechanical Properties of a Novel 0.4C Press-Hardening Steel

2019 ◽  
Vol 9 (20) ◽  
pp. 4231
Author(s):  
Oskari Haiko ◽  
Antti Kaijalainen ◽  
Sakari Pallaspuro ◽  
Jaakko Hannula ◽  
David Porter ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Temperature ◽  
Impact Toughness ◽  
Retained Austenite ◽  
Hot Strip Mill ◽  
Tempering Temperature ◽  
Press Hardening ◽  
Dislocation Densities ◽  
The Impact

In this paper, the effects of different tempering temperatures on a recently developed ultrahigh-strength steel with 0.4 wt.% carbon content were studied. The steel is designed to be used in press-hardening for different wear applications, which require high surface hardness (650 HV/58 HRC). Hot-rolled steel sheet from a hot strip mill was austenitized, water quenched and subjected to 2-h tempering at different temperatures ranging from 150 °C to 400 °C. Mechanical properties, microstructure, dislocation densities, and fracture surfaces of the steels were characterized. Tensile strength greater than 2200 MPa and hardness above 650 HV/58 HRC were measured for the as-quenched variant. Tempering decreased the tensile strength and hardness, but yield strength increased with low-temperature tempering (150 °C and 200 °C). Charpy-V impact toughness improved with low-temperature tempering, but tempered martensite embrittlement at 300 °C and 400 °C decreased the impact toughness at −40 °C. Dislocation densities as estimated using X-ray diffraction showed a linear decrease with increasing tempering temperature. Retained austenite was present in the water quenched and low-temperature tempered samples, but no retained austenite was found in samples subjected to tempering at 300 °C or higher. The substantial changes in the microstructure of the steels caused by the tempering are discussed.

Impact toughness of welds deposited on H13 hot work tool steel

2014 ◽  
Vol 105 (8) ◽  
pp. 735-742
Author(s):  
Matjaž Mulc ◽  
Andrej Skumavc ◽  
Boštjan Taljat ◽  
Janez Tušek
Keyword(s):  
Impact Toughness ◽  
Tool Steel ◽  
Hot Work Tool Steel
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