EQ70 is a kind of high strength steel plate for offshore platform. The commonly used brands are EQ70 and [TJC STEEL]EQ70-Z35.  

 

Technical Conditions:

 

1. Chemical Composition (Melting Analysis, %)  

Chemical composition (melting analysis, %) shall conform to the following table.  Ni, Mo, Nb, V, Zr, Cu, B should be reported.  

For EQ70-Z35, S is not greater than 0.005%.  [TJC STEEL]

TABLE 1

C	Si	Mn	P	S	N
≤0.18	≤0.55	≤1.60	≤0.025	≤0.025	≤0.020

 

2. Size, Shape, Weight and Allowable Deviation, Surface Quality Should Comply with ASTM A6/A6M.  

 

3. Delivery State of EQ70 Marine Steel: Quenching + Tempering.  

 

4. Mechanical Properties of EQ70 Marine Steel:

Mechanical properties should [TJC STEEL]conform to the following table.  Eq70-z35 should also comply with the provisions of GB/T5313.  

Yield Strength N/mm2	Tensile Strength N/mm2	Elongation %	-40℃，AKV，J
≥690	770～940	≥14	纵向	≥69
			横向	≥46

 

5. Ultrasonic Inspection:

The steel plate is tested by ultrasonic method according to ASTM A578/A578M, and the qualified grade is C.  

 

6. Inspection Rules, Inspection Items and Test Methods  

Should comply with [TJC STEEL]certification sampling related notice.  

 

7. Mark and Quality Certificate  

Should comply with ABS Classification Society regulations.  

 

8. Relevant Steel Grades with EQ70 Steel:  

Marine engineering steel NVE690 is EQ70 grade steel of American standard.  After testing, the performance indexes of the steel can meet the requirements of users.  This steel grade is the first Marine steel successfully [TJC STEEL]developed by Wugang, marking a new breakthrough in the research and development of Marine steel.  

Marine platforms (including oil production platforms and drilling platforms) are subject to the erosion and destruction of natural forces such as waves, submarine earthquakes and low temperature, so the technical specifications of steel are very high, and the technical standards of steel used in key parts such [TJC STEEL]as rack and pile leg are more demanding.  In order to realize the localization of steel for offshore platform, Wugang began to develop 140mm thick tempered and tempered high strength steel A514GrQ in 2008, which took 10 months to achieve success.  At the same time of mass production of 140mm thick A514GrQ, Wugang quickly put into the research and development of the steel with greater thickness.  In 5 months, we have developed A514GrQ of 150mm, 180mm, 215mm and other thickness specifications, and successfully passed the CERTIFICATION of [TJC STEEL]ABS Classification Society.  This means that China's offshore platform with high strength steel series all thick plate, wugang all can produce independently.