Effect of welding heat input on microstructures and toughness in simulated CGHAZ of V–N high strength steel

2013 ◽  
Vol 577 ◽  
pp. 161-168 ◽  
Author(s):  
Jun Hu ◽  
Lin-Xiu Du ◽  
Jian-Jun Wang ◽  
Cai-Ru Gao
Keyword(s):  
Heat Input ◽  
High Strength Steel ◽  
High Strength ◽  
Welding Heat Input

Effect of Microstructure on CTOD of Welded Joints for Offshore High-Strength Steel

2011 ◽  
Vol 117-119 ◽  
pp. 1905-1911
Author(s):  
Li Na Niu ◽  
Zhang Mu Miao ◽  
Tao Ma ◽  
Gang Chen
Keyword(s):  
Welded Joints ◽  
Heat Input ◽  
High Strength Steel ◽  
High Strength ◽  
Point Of View ◽  
Welding Heat Input ◽  
The Matrix ◽  
Welding Procedure ◽  
Carbide Particles ◽  
Effect Of Microstructure

Based on the CTOD test, metallographic test is done. The effect of microstructure on CTOD of welded joints for offshore high-strength steel has been analyzed by SEM. The microstructure of different samples in a welding procedure and two different welding procedures are compared. From the microscopic point of view, the reasons why the toughness of the second group welded joints is better than the first group’s and why the toughness of the same group welded joints is different have been determined. And the main microstructure found in EQ70 steel welded joints is the ferrite, tempered sorbite and a small amount of pearlite. Besides some carbide particles are on the matrix of tempered sorbite. The material toughness with a small amount of acicular ferrite is better. Inclusions and pores also seriously affect the toughness of welded joints. Reducing the welding heat input appropriately can refine the grain of CGHAZ and improve toughness. But hardened microstructure may occur owing to too low welding heat input.

Thermal Simulation Study of 900MPa Grade High-Strength Low Alloy Steel in Welding Procedures

2011 ◽  
Vol 704-705 ◽  
pp. 1128-1132
Author(s):  
Di Xin Yang ◽  
Yuan Fang Sun
Keyword(s):  
Alloy Steel ◽  
Heat Input ◽  
High Strength ◽  
Weld Bead ◽  
Peak Temperature ◽  
Welding Parameters ◽  
Chemical Compositions ◽  
Low Alloy Steel ◽  
Hydraulic Support ◽  
Welding Heat Input

Hydraulic support is an important part of fully mechanized equipments. The constructional steels of hydraulic support with international advanced level mainly adopt the high-strength welding structural steel with its tensile strength of more than 700~1000MPa.This paper analyzes the chemical compositions features of S890 high-strength low alloy steel for 900MPa grade.The Influence of welding parameters,peak temperature and on the microstructures and mechanical properties of welding HAZ of S890 high-strength low alloy steel were investigated by thermo-simulated tests, The influence of welding heat input on the mechanical behaviors of the welded joint was also investigated. The results show that the microstructures of S890 steel change from tempered martensite to bainite and a little ferrite , pearlitic when welding heat input changes from low to high, and accompany the austenite grains coarsening ,so the impact toughness and hardness of welding HAZ at lower peak temperatures and shorter are higher than that at higher peak temperature and long . Welding HAZ produced by the second weld bead will overlap partially with the HAZ produced by the first weld bead. In this area, primitive microstructure tempers again or partial re-phase transformations and re-cools,but the area involved in the overlap is limited,so the influence on the properties of S890 steel is not obvious. In covered arc welding,the influence on the welded join strength of S890 steel is not distinct when heat input change in a certain scope, but the plasticity of the welded join falls off steeply as heat input increases. Keywords: S890 steel; high-strength low alloy steel; weld performance; hydraulic supports

Feasibility study of welding dissimilar Advanced and Ultra High Strength Steels

2020 ◽  
Vol 59 (1) ◽  
pp. 54-66
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Antti Salminen ◽  
Mvola Belinga ◽  
Xiaochen Yang
Keyword(s):  
Heat Input ◽  
High Strength Steel ◽  
Gas Metal Arc Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Hardness Test ◽  
Welding Parameter ◽  
Welding Parameters

AbstractThis study concerns the weldability of dissimilar Ultra high-strength steel (UHSS) and advanced high-strength steel (AHSS), which is used in the modern machine industry. The materials offered superior strength as well as relatively low weight, which reduces microstructure contamination during a live cycle. The choice of the welding process base of the base material (BM) and welding parameters is essential to improve the weld joint quality. S700MC/S960QC was welded using a gas metal arc welding (GMAW) process and overmatched filler wire, which was performed using three heat input (7, 10, and 15 kJ/cm). The weld samples were characterized by a Vickers-hardness test, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The test reveals a decrease of softening areas in the HAZ and the formation of the stable formation of Bainite-Ferrite for S700MC and Bainite-martensite for S960QC when the heat input of 10 kJ/cm is used. It is recommended to use the GMAW process and Laser welding (Laser beam-MIG), with an optimal welding parameter, which will be achieved a high quality of manufacturing products.

scholarly journals Improvement in Microstructure and Toughness of Large Heat-input Weld Bond of High Strength Steel Due to Addition of Rare Earth Metals and Boron

1977 ◽  
Vol 17 (7) ◽  
pp. 419-427 ◽  
Author(s):  
Tokushi FUNAKOSHI ◽  
Tomoo TANAKA ◽  
Syuzo UEDA ◽  
Masaaki ISHIKAWA ◽  
Noriaki KOSHIZUKA ◽  
...  
Keyword(s):  
Rare Earth ◽  
Heat Input ◽  
High Strength Steel ◽  
Rare Earth Metals ◽  
High Strength ◽  
Large Heat

Influence of the Weld Heat Input on the Electrochemical Behavior of the 921A High Strength Steel Welding Joints

2015 ◽  
Vol 817 ◽  
pp. 312-318
Author(s):  
Kai Wang ◽  
Jiang Long Yi ◽  
Shi Da Zheng ◽  
Chun Fu Guo ◽  
He Xin Chen ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Heat Input ◽  
High Strength Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Cored Wire ◽  
Input Condition ◽  
Base Steel ◽  
Welding Joints ◽  
Weld Heat

Using the prepared gas-shielded flux-cored wire for welding 600MPa high strength steel, the 921A high strength steels were welded at different weld heat input condition of 10 kJ/cm, 15 kJ/cm and 20 kJ/cm. The influence of weld heat input on the electrochemical behavior of the 921A high strength steel welding joints were studied in this paper. The results show that, at different weld heat input condition, the linear polarization resistances (LPR) of all the welding joints welded by using the prepared flux-cored wire were close to that of the 921A base steel, as can be identified as the same LPR value at 15 kJ/cm weld heat input condition. By observing the surfaces of the linear polarized welding joints samples, it was found that the welding joint at 15 kJ/cm weld heat input had the smallest corrosive area by macro observing, showing the pitting corrosion by micro observing and presents the least corrosion pit.

Sign in / Sign up

Export Citation Format

Share Document