The Influence of Phosphorous Alloy Additions on the Zinc Phosphate Coating Formation on Cold Rolled Steels

CORROSION ◽  
1982 ◽  
Vol 38 (4) ◽  
pp. 201-206 ◽  
Author(s):  
James A. Kargol ◽  
Donald L. Jordan
Keyword(s):  
Zinc Phosphate ◽  
Sheet Steel ◽  
Steel Corrosion ◽  
High Strength ◽  
Phosphate Coating ◽  
Hydrogen Recombination ◽  
Abrasive Surface ◽  
Coating Formation ◽  
Cold Rolled ◽  
Steel Corrosion Resistance

Abstract One of the more common and economical means of producing cold rolled and annealed sheet steel with high strength and formability is by alloying with phosphorous (P). However, the P alloy additions have been found to increase the porosity in zinc phosphate pretreatment coatings which, in turn, may reduce painted steel corrosion resistance. Electrochemical measurements indicated that P increases phosphate coating porosity by inhibiting hydrogen recombination during the first stages of phosphate coating formation. Abrasive surface conditioning of rephosphorized steel did not remove the inhibiting effect of P; thus, bulk P, and not P that segregated to the surface during annealing, was responsible for the effect.

Continuous Cooling Transformation Behavior of High Strength Low-Alloyed Cold Rolled Sheet Steel

2007 ◽  
Vol 26-28 ◽  
pp. 27-31 ◽  
Author(s):  
Hao Liu ◽  
Ding Zhong Zhong ◽  
Long Qi Zhao ◽  
Tao Peng ◽  
Li Xin Wu ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Sheet Steel ◽  
High Strength ◽  
Deformation Condition ◽  
Rolled Sheet ◽  
Transformation Temperatures ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Critical Phase ◽  
Cold Rolled

The dilatometry curves and the critical phase transformation temperatures of high strength low-alloyed (HSLA) cold rolled sheet steel were determined by thermal simulation test machine. The samples were austenitized at 900°C,deformed at 40% of deformation and cooled at different rates of 0.1°C/s~ 60°C/s. The continuous cooling transformation (CCT) diagram under deformation condition can be drawn. The results showed that the critical phase transformation temperatures are as follows: Ac3=900°C, Ac1=735°C, Ar3=825°C, Ar1=695°C. A few amount of martensite in high strength low-alloyed cold rolled steel can be obtained at the cooling rate of 60°C/s. The experimental data provide the technical references for rolling control, cooling control and heat treatment in real production.

scholarly journals Texture Distributions Through the Thickness of an ELC-BH Sheet With Very High r¯-Value Produced by a New Technology

1998 ◽  
Vol 30 (3-4) ◽  
pp. 229-245
Author(s):  
Xiaojun Guan ◽  
Jiajuan Zhou ◽  
Xiaojun Hu ◽  
Qiulin Wu
Keyword(s):  
New Technology ◽  
Sheet Steel ◽  
High Strength ◽  
Fiber Axis ◽  
Rolled Sheet ◽  
Low Carbon ◽  
Annealing Texture ◽  
Cold Rolling And Annealing ◽  
Cold Rolled ◽  
Very High

Effects of a new technology which made r¯-value increase remarkably on the distributions of the cold rolling and annealing textures through the thickness of an extra low-carbon and high strength bake-hardening sheet steel have been researched by means of the method of ODF. The results are expressed as follows: (1) γ-fiber axis texture in the ELC-BH sheet obtained by the new technology develops so strongly and purely, especially within the sheet. This is the essential cause why r¯-value of the sheet remarkably increases. (2) The very strong γ-fiber axis texture of being completely different from conventional one is closely related to the cold rolled sheet supplied by the new technology which benefits to develop {111} annealing texture strongly. The inside of the cold rolled sheet is far more favorable than its surface to the development of the γ-fiber axis texture.

Pre-Treatment of Niobium Phosphate for Protection against Carbon Steel Corrosion

2016 ◽  
Vol 869 ◽  
pp. 716-720
Author(s):  
Osmar dos Reis Antunes Jr. ◽  
Larissa Aparecida Corrêa Matos ◽  
Larissa Oliveira Berbel ◽  
Claudia Schlindwein ◽  
Paulo Vitor Sochodolak ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Open Circuit Potential ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Open Circuit ◽  
Phosphate Coating ◽  
Metallic Material ◽  
Pre Treatment ◽  
Niobium Phosphate

This work proposes the development of a niobium phosphate coating (PNb) to replace the zinc phosphating, which is very aggressive to the environment and human health. The metallic material utilized was carbon steel (SAE 1010), which was coated with sunbathing - gel containing phosphate and niobium. A traditional zinc phosphate coating was used for comparison of results. The samples were characterized by scanning electron microscopy (SEM), dispersive energy spectroscopy (DES), open circuit potential, electrochemical impedance spectroscopy and anodic polarization. The results demonstrated that the samples coated with niobium phosphate have more surface nobility and greater corrosion resistance.

Galling and Die Build-Up in Forming Uncoated, Cold-Rolled Advanced High-Strength Steels (AHSS)

2015 ◽  
Author(s):  
Hua-Chu Shih
Keyword(s):  
Surface Texture ◽  
Steel Surface ◽  
Sheet Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Roll Surface ◽  
Friction Forces ◽  
Advanced High Strength Steels ◽  
Cold Rolled ◽  
Bending Under Tension

Uncoated advanced high strength steels (AHSS) are being used for non-exposed automotive applications where high strength is required. Due to higher contact pressures and friction forces between the tooling and sheet steel, increased die wear, die build-up and sheet steel surface galling have been observed. Although various countermeasures have been adopted in production to address these issues, the stamping die tryout process has not been revised accordingly. Proper heat treatment of uncoated tryout dies is required to prevent wear in stamping uncoated, cold-rolled AHSS. Whether die build-up and sheet steel surface galling occur depends on the steel surface condition. The intent of this study is to investigate the effects of steel surface topography on die build-up, sheet steel surface galling and friction in forming uncoated cold-rolled AHSS. DP590 and DP980 with different thickness and different finish rolled textures were tested with the bending under tension (BUT) tester to study these effects. A reciprocal cyclic bend test system (CBTS) of modifying bending under tension test was used to investigate wear and build-up between different surface texture steels in a production condition. Results indicate that the finish roll surface texture is found to be the root cause for the die build-up and steel surface galling that occurs during forming with uncoated dies. The ground-roll surface is the worst in terms of galling and build-up while the Electro-Discharge Textured (EDT) surface is the best. The surface parameters Skewness (Rsk) and Kurtosis (Rku) are found to be able to assess steel galling and die build-up behaviors for uncoated cold rolled AHSS using the uncoated D2 die. A surface with Rsk larger than −0.5 and Rku less than 3 can prevent galling and die build-up in the die tryout process, which is recommended to finish roll the uncoated cold rolled AHSS.

YOUNGSTOWN YS-T50 to YS-T140 STEELS

Alloy Digest ◽  
1977 ◽  
Vol 26 (4) ◽  
Keyword(s):  
Physical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treating ◽  
Steel Alloy ◽  
Bend Strength ◽  
Weight Saving ◽  
Cold Rolled ◽  
Hot Rolled ◽  
Minimum Yield

Abstract YS-T 50 to YS-T 140 Steels comprise a series of high-strength, cold-rolled steels designed to meet performance and weight-saving objectives. They are an extension of Youngstown's series of hot-rolled high-strength steels (see Youngstown YS-T Steel, Alloy Digest SA-261, March 1971). The YS-T 50 to YS-T 140 steels have minimum yield strengths ranging from 50,000 psi to 140,000 psi. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on heat treating, machining, and joining. Filing Code: SA-331. Producer or source: Youngstown Sheet and Tube Company.

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