VI

Design & Development

No

Name

Description

Client / Employer

45

Development of roll pass schedule for the first Chinese Tension-Reducing mill for pipe production

The pass schedule was developed to use tension to control the wall thickness of the pipe while the pipe diameter was reduced in the roll gap (the groove of the rolls). Three weeks of tuning in the steel pipe mill was needed to test the designed schedule. Worked with Prof. Yuqiu Lu, a steel pipe production expert and the former dean of the college of Metal Forming of UISTB.

Yantai Pipe

46

Flat rolling of the samples with outer or inner grids

Flat rolling of the DIN 19Mn6 steel samples with outer or inner grids (i.e., surface or cross-section grids). The rolling was done to study the grid behavior during rolling and to obtain the rolling parameters and the local material flow. A so-called "stecker-rolling" was also done by interrupting the roll movement while the stock was still in the roll gap, so that it became possible to establish the form of the work piece in the roll gap. The results from measurement were used to verify FEM model.

DFG

47

Roll pass design for angle steel rolling from square in six passes

Because the hot rolling tests of the angle steel rolling involved several rounds of the tests and used nearly 100 samples with grids milled on the surface or the cross-section, roll pass design for the angle steel rolling was carefully performed based on early rolling experience. A special roll pass sequence was developed through a combination of the butterfly method and the design method for a continuous mill.

DFG

48

Angle steel rolling starting from square and intermediate shapes, with outer or inner grids

DIN 19MN6 steel with the original cross-section of 48x48mm was rolled at 900?C in six passes until the final form of angle steel 40x40x9mm was achieved. Outer or/and inner grids were milled on the outer surfaces and inner cross-sections for the entry shapes of all passes. For this, a pre-rolling was done to produce entry shapes of all passes. After rolling, the global and local metal flow for all the passes, in outer surfaces and cross-sections, as well as the temperature, force, torque, power, etc. were measured. The results were used to study metal deformation and the force/power requirements, and to verify the FEM model established for angle steel rolling.

DFG

49

Morgan??s roll pass design procedure examination to identify weakness

Requested by Morgan?s top management to examine its roll pass design procedure, and to make improvements if any problems were identified.

Morgan

50

No-Twist Mill (NTM) field data collection from former ASW

Traveled to former ASW, Cleveland, OH, to collect data from Morgan?s high-speed No-Twist mill. Cross-sections, speed, width, etc. for each pass in the mill block were measured. A hole was cut in each stand box to measure the needed data. This work was done together with another others at Morgan.

Morgan

51

Round-square roll pass design for several finishing mills

Several customers of Morgan wanted to adapt the products of finishing mills, usually round products, into squares. The round-to-square passes in the high-speed finishing mills were developed for this purpose.

Morgan

52

Roll pass design for GST 8-stand mill for 28 sizes with two sizes of billet

This mill had 8 stands with the last 4 stands tied (driven by a single motor). Due to the high average reduction, tension had to be used in some passes to achieve the finish size. During the design, a simple roll pass program was created based on MS-Excel by integrating various rolling process models that were developed earlier.

Morgan

53

Coating of Zn-Al alloys on steel and coat quality testing

This was a part of a surface treatment project with Prof. Yuqiu Lu and then Ph.D. Candidate, Angang Hu (now a well-known economist). Used US demonstration equipment to apply the Zn-Al coating on the surface of a plate, and then measured coat quality parameters. A new coating mechanism was proposed based on microscopic observations (800X photographs of the coating layer) and the measured data.

Petroleum Ministry, China

113

Roll Pass and Mill Design/Development for POSCO SS

This was a roll pass design and development project served as the guideline in the mill design for the POSCO Specialty Steel Ltd. A new breakdown mill is to be added into current plant. The mill is under various constrains: (1) Single stand reversing mill, with limited number of grooves cut on the roll; (2) Big ingot (700mm square) and bloom (420mm x 530mm), to be rolled into round 270 ~ 320mm and square 200~300mm, but number of passes to be minimal due to temperature concern; (3) Smallest roll diameter (new/discard) required due to space and bearing restrictions, and so bite condition was hard to meet; (4) Smallest barrel length required due to limited crane capacity; (5) Passes involves both round and square, minimal number of grooves hard to achieve; (6) Hard steel to be rolled, with strength 30% higher than AISI 1080; (7) Some steel with 30% higher spread than average, and so the minimal number of passes hard to reach; (8) Crack to be avoided since some steel has low formability. In addition, number of passes in grooves should be balanced to achieve maximum roll life. Satisfied design was achieved with all conditions met, and corresponding roll force/torque checkup also passed.

POSCO

114

Various design and development for Asia

Various design and development for India, Pakistan and Arabian countries, on roll pass and force prediction, etc. The projects were primarily acquired through Metal Data web presence.

Asia