Indentation creep measurements using a Rockwell hardness tester

1991 ◽  
Vol 26 (1) ◽  
pp. 75-81
Author(s):  
V. R. Howes
Keyword(s):  
Indentation Creep ◽  
Rockwell Hardness ◽  
Hardness Tester ◽  
Creep Measurements

Development of High-Precision Portable Rockwell Hardness Tester

2018 ◽  
Vol 16 (8) ◽  
pp. 27-33
Author(s):  
Shin-Gon Kim ◽  
Jee-Youl Ryu
Keyword(s):  
High Precision ◽  
Rockwell Hardness ◽  
Hardness Tester

The Influence of Laser Hardening on the Microstructure and Wear Resistance of Disk Opener

2010 ◽  
Vol 97-101 ◽  
pp. 1497-1501 ◽  
Author(s):  
Hao Sun ◽  
Gang Ling ◽  
Hong Wen Li ◽  
Yan Bo Su ◽  
Shao Ping Xiong ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Phase Transformation ◽  
Laser Power ◽  
Hardened Layer ◽  
Solid State Laser ◽  
Laser Hardening ◽  
Rockwell Hardness ◽  
Transformation Zone ◽  
Hardness Tester ◽  
Melted Zone

The microstructure and properties of hardened layer of 45 steel disk opener with a variety of parameters of HLD1001.5 solid-state laser were studied by SEM, Rockwell hardness tester and wear tester. The results showed that under the conditions of the laser power from 400W to 600W, the hardened layer is composed of melted zone, phase transformation zone and heat affected zone, and the hardness is up to 58.5-61HRC, and the disk openers have excellent wear resistance after the laser hardening, which is best in the disk opener with the treatment of laser power 500W.

Effect of CeO2 on Microstructure and Hardness of Roller Surface Alloyed by Laser

2012 ◽  
Vol 155-156 ◽  
pp. 877-880
Author(s):  
Huai Jun Yue ◽  
Qi Bin Liu
Keyword(s):  
Co2 Laser ◽  
Testing Machine ◽  
Surface Hardness ◽  
Service Performance ◽  
Micro Hardness ◽  
Rockwell Hardness ◽  
Hardness Testing ◽  
Coating Materials ◽  
Hardness Tester ◽  
Molten Liquid

To improve the service performance of roller. The surface of roller was alloyed by a 5kW CO2 laser. The effect of CeO2 on microstructure and hardness was studied by means of OM, Micro-hardness Testing Machine and Rockwell hardness tester. The results indicate that addition of CeO2 into coating materials can enhance the fluidity of molten liquid, refine and purify microstructure and increase microhardness and surface hardness of alloying coating.

Hardness Test and Error Analysis of N80 Oil Casing

2013 ◽  
Vol 779-780 ◽  
pp. 161-164
Author(s):  
Ding Feng ◽  
Zhi Min Li ◽  
Hong Zhang ◽  
Lei Shi ◽  
Wei Ma ◽  
...  
Keyword(s):  
Error Analysis ◽  
Hardness Test ◽  
Pressure Head ◽  
Test Sample ◽  
Rockwell Hardness ◽  
Load Pressure ◽  
Hardness Tester ◽  
Measurement Results ◽  
Causes Of Errors ◽  
Petroleum Drilling

N80 oil casing is important equipment in petroleum drilling, to analyze the mechanical features of the N80 casing; we used Rockwell apparatus to test the hardness of N80 casing. And we have analyzed and eliminated the errors which may affect the result of the hardness test to ensure the reliability. At the same time, it summed up the causes of errors and the methods to avoid and reduce the errors during the Rockwell hardness test, and analyzed the hardness tester load, pressure head, the structure as well as the test sample roughness, shape and other factors which influenced the measurement results. Keywords: n80 oil casing; hardness test; error analysis

Effect of Cryogenic Treatment on Improving the Fracture Toughness of TiN Coated Cemented Carbide

2011 ◽  
Vol 415-417 ◽  
pp. 1903-1910 ◽  
Author(s):  
Chao Yin Nie ◽  
Ya Deng ◽  
Ying Ding ◽  
Ning Li ◽  
Xiao Gang Zhou ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Cryogenic Treatment ◽  
Cemented Carbide ◽  
Rockwell Hardness ◽  
Tin Coating ◽  
Ion Plating ◽  
Hardness Tester ◽  
Tin Coatings ◽  
Before And After ◽  
Coated Cemented Carbide

The 2μm thick TiN coatings were deposited by arc ion plating on YW2 cemented carbide substrate, and the system of TiN/YW2 was treated with cryogenic treatment at -196°C for 30 hours. The change of the Rockwell indentation's morphology of the system (the form and density of cracks, the spalling state of the coating)before and after the treatment were investigated by means of the Rockwell hardness tester. With metallurgical microscope and SEM, the change of the microstructure of the substrate and its influence on the fracture toughness of the system were investigated. The results show that after the treatment, the density of the radiated cracks in the substrate were obviously reduced, but the main cracks hadn’t any change, the spalling of the TiN coating along the indentation was lightened. After the cryogenic treatment the dispersed granular γ phase obviously decreased or even disappeared, the pores became smaller and the microstructure of YW2 became more compact，and the microcracks were merged during the cryogenic treatment. These are beneficial to improve the fracture toughness of YW2 substrate and the coating/substrate system.

Effect of Ultrasonic Impact Strengthening Treating on Microstructure and Properties of AZ91D Magnesium Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 382-385 ◽  
Author(s):  
Bo Lin He ◽  
Ying Xia Yu ◽  
Yan Ping Miao
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Research Report ◽  
Rockwell Hardness ◽  
Impact Time ◽  
Surface Strengthening ◽  
Hardness Tester ◽  
Scratch Hardness ◽  
Az91d Magnesium Alloy ◽  
Change Characteristics

Magnesium alloy is one of the most useful structural materials in the future. But the research report about surface strengthening of magnesium alloy is little in home and abroad. Ultrasonic impact strengthening treatment was carried out on AZ91D magnesium alloy, the change characteristics of surface microstructure was studied using SEM. The scratch hardness and wear-resistance were tested for both ultrasonic impact treatment and un-treated specimen using HRA-150 type Rockwell hardness tester and M-2000 model wear tester. The experimental results indicate that after ultrasonic impact, the grain boundary on the surfaces of AZ91D is obviously refined. When the ultrasonic impact time are 20 min, 30 min and 50 min, the scratch hardness on the surface of AZ91D increases 7.2%, 16.96% and 28.90%, respectively. For ultrasonic impact time of 50 min, the wear-resistance of treated specimen could be increased to 39.63% and 37.56% respectively for the wear time for 2 and 5 min. With increasing the ultrasonic impact time, the wear scar on the surface is become narrow. It is an effective method to increase the scratch hardness and wear-resistance of AZ91D magnesium alloy by using ultrasonic impact strengthening treatment.

Deposition and Characterization of Boron-Doped HFCVD Diamond Films on Ti, SiC, Si and Ta Substrates

2012 ◽  
Vol 217-219 ◽  
pp. 1062-1067 ◽  
Author(s):  
Xin Chang Wang ◽  
Bin Shen ◽  
Fang Hong Sun
Keyword(s):  
Diamond Films ◽  
Indentation Test ◽  
Rockwell Hardness ◽  
Trimethyl Borate ◽  
Boron Doped Diamond ◽  
Hardness Tester ◽  
Boron Doped ◽  
Deposition Parameters ◽  
Fesem Micrographs

In the present investigation, titanium (Ti), silicon carbide (SiC), silicon (Si) and tantalum (Ta) samples with the same geometry are selected as substrates to deposite HFCVD boron-doped diamond films with the same deposition parameters, using trimethyl borate as the dopant. FESEM, EDS, Raman spectroscopy and Rockwell hardness tester are used to characterize as-deposited boron-doped diamond (BDD) films. The FESEM micrographs exhibit that the film deposited on Si substrate presents the best uniformity and that on Ti substrate has smallest grain size and film thickness, with titanium element detected in the EDS spectra. Moreover, it’s speculated by indentation test that the adhesive strength between the BDD films and different substrates can be order as SiC>Ta>Ti for the different thermal expansion coefficient gaps between the substrate and diamond, and the hardness of the BDD coated samples measured using Rockwell hardness tester can also be order as SiC>Ta>Ti due to the different hardness of substrate materials. Finally, similar and representative characterization for BDD films is obtained from the Raman spectra for all the BDD films on different substrates.

scholarly journals Hardness Test of Grinding Wheel by the Rockwell Hardness Tester (Continued)

1955 ◽  
Vol 21 (111) ◽  
pp. 886-889
Author(s):  
Toshio ASAEDA ◽  
Koji ONO
Keyword(s):  
Hardness Test ◽  
Grinding Wheel ◽  
Rockwell Hardness ◽  
Hardness Tester

Experimental Study on Repairing Large Modulus Rack Cracks by Argon Arc Welding

2019 ◽  
Vol 943 ◽  
pp. 8-13
Author(s):  
Jiao Yan Yu ◽  
Duan Wei Shi ◽  
Zhi Li ◽  
Shuang Yang Yu ◽  
Yang Zhang
Keyword(s):  
Arc Welding ◽  
Welding Current ◽  
Substrate Material ◽  
Rockwell Hardness ◽  
Influence Of Process Parameters ◽  
Hardness Tester ◽  
Argon Flow ◽  
Welding Technology ◽  
Preheating Temperature ◽  
Crack Repair

The crack repair experiment with argon arc welding technology was carried out to repair large cracks in the large-module gear and rack of the shiplift. The experiment studied the influence of process parameters including welding current and prehearing temperature on the properties of the weld by using 40CrMo piece with pre-made cracks as the substrate material and TIG-R30 wire. In addition, Rockwell hardness tester and material high temperature performance tester were used to test the hardness and tensile properties of the weld. The result shows that the best performance of the welds was obtained when the welding current was 150A, the preheating temperature was 100°C and the argon flow was 15L/min. At this point, the hardness of the weld was 12.8% higher than that of the substrate with the tensile strength reaching 786Mpa, the elongation being 8% and no cracks or pores.

Influence of Surfacing Current on Microstructure and Wear Resistance of Fe60 Alloy Surfacing Coating

2016 ◽  
Vol 709 ◽  
pp. 51-56
Author(s):  
Bo Chen ◽  
Yi Li ◽  
Peng Xiao Zhu ◽  
Hui Ji Fan ◽  
Cai Tang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Optical Microscopy ◽  
Dynamic Load ◽  
Surface Coating ◽  
Alloy Surface ◽  
Rockwell Hardness ◽  
Hardness Tester ◽  
Plasma Surfacing ◽  
Equiaxed Grains

Fe60 alloy surface coating was prepared on Q345 by plasma surfacing. The hardness and wear resistance of surfacing coating were tested by Rockwell Hardness Tester and dynamic load abrasive abrasion Tester. The microstructure of surfacing coating was studied by Optical Microscopy. The Influence of the surfacing current on hardness, microstructure and wear resistance were investigated.The results showed that, the samples prepared by 140 A exhibited excellent wear resistance, meanwhile many equiaxed grains were observed to distribute uniformly in the samples.

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