【摘 要】
:
For galvanized or galvannealed steels to be commercially successful,they must exhibit several attributes:(i)easy and inexpensive processing in the hot mill,cold mill and on the coating line,(ii)high s
【机 构】
:
Basic Metals Processing Research Institute Mechanical Engineering and Materials Science University o
论文部分内容阅读
For galvanized or galvannealed steels to be commercially successful,they must exhibit several attributes:(i)easy and inexpensive processing in the hot mill,cold mill and on the coating line,(ii)high strength with good formability and spot weldability,and(iii)good corrosion resistance,especially after cold forming.For good corrosion resistance,the coating must have sufficient coverage,be of uniform thickness,and most importantly,the coating must survive the cold stamping or forming operation.The purpose of this paper is to present research aiming at improving the steel substrate,such that high strength can be obtained while maintaining good global formability(tensile ductility),local formability(sheared-edge ductility),and good spot weldability.It is well-known that the strength of DP steels is controlled by several factors,including the amount of martensite found in the final microstructure.Recent research has revealed that the amount of austenite formed during intercritical annealing can be strongly influenced by the annealing temperature and the pre-annealing conditions of the hot band(coiling temperature)and cold band(%cold reduction).Current experiments have explored the combination of pre-annealing conditions and four annealing practices to help define the best practice to optimize the strength-formability balance in these higher strength DP steels.The steels used in these experiments contained(i)low carbon content for good spot weldability,(ii)the hardenability additions Mo and Cr for strength,and(iii)V for grain refinement,precipitation hardening and temper resistance.When processed correctly,these steels exhibited UTS levels up to 1000MPa,total elongation to 25%,reduction in area to 45%,and Hole Expansion Ratios to 50%.The results of this program will be presented and discussed.
其他文献
For the purpose of obtaining the optimal microstructures and mechanical properties of the CGHAZ under high input welding,continuous cooling transformation diagrams of the coarse grain heat-affected zo
Continuous cooling transformation diagrams and microstructures of coarse grain heat-affected zone(CGHAZ)of V-N-Ti and Nb-V-Ti microalloyed steels at different cooling time form 800℃ to 500℃(t8/5)were
Ultra-high strength steels are materials of considerable interest for automotive and structural applications and are increasingly being used in those areas.Higher strength,however,makes steels more pr
Shougang Group has developed advanced high-strength wear-resistance steel of NM450 by using Nb-Mo-Cr-Ti-B micro-alloyed design and two-stage rolling and quenching and tempering process.In spite of hig
Effects of galvanizing simulation parameters on microstructures and mechanical properties of Timicroalloyed cold rolled hot-dip galvanizing DP980 steel were investigated in this study by optical micro
Press hardening has become the state-of-art technology in the car body manufacturing to enhance safety standard and to reduce CO2 emission of new vehicles.However the delayed cracking due to hydrogen
Hot-dip galvanizing dual phase steel DP600 steel grade with low Si was produced by steel plant and experiments by simulating galvanizing thermal history.The microstructure was observed and analyzed by
When producing high surface quality galvanizing steel coils for automobile use,there are always many light spots on the surface since Hansteel CGL No.1 has been put into operation.The defect samples w
In this paper,against the actual operating condition of the low alloy CrMo wear-resistant steel liner plate,the influence of Nb on the microstructure and properties of the low alloy CrMo steel were in
Lightweight wheels can reduce weight about 100kg for commercial vehicles,and it can save energy and reduce emission,whats more,it can enhance the profits for logistics companies.The development of lig