H11/ DIN 1.2343 & H13/ DIN 1.2344 grades require Extra Fine Structure in Spherodised annealed condition. The structure must conform to GA / GA1 & GB / GB1 as per the standard VDEh SEP 1614.
GSSL has developed special heat treatment cycle to achieve such microstructure. GSSL is successfully exporting and supplying to the domestic customers to the customer’s satisfaction.
EFS SPHEROIDISED MICROSTRUCTURE
HARDENED & TEMPERED MICROSTRUCTURE
Micro structure as per GA1/GA2/GA3/GA4/GA5 & GB1 / GB2/GB3/GB4 / GC1 / GC2 / GD1 /GD2 / GE1 & Banding as per SA 1 / SA2/ SA3 & SA4, as per VDEh rating chart for the evaluation of Microstructure of Annealed Hot-Work Tool Steels AND rating chart for the evaluation of the Alloy’s Microhomogeneity of Hot Work Tools Steels are defined as Premium Quality steels. We supply Premium Quality EFS steel.
Even tough we guarantee as above, 90% of our production is within GA 1 / GA 2 / GB 1 / GB 2 & Banding SA1.
100% PRIMARY SLAG REMOVAL IN PROGRESS
The Primary slag after melting the scrap contains many undesirable elements & inclusions. 100% of this primary slag must be removed before the molten steel is treated in LRF and VD. GSSL has developed a special process to ensure 100% removal of primary slag. This ensures very clean steel containing low S & P.
In Arc Furnaces, even with EBT, there is a probability of Slag escaping while tapping. However GSSL process ensures 100% primary slag removal.
Goradia Steel has developed a In-House arrangement to Air Quench Steel. The specially designed facility ensures Cyclone Type Air Blast on Steel. Such Cyclone effect Air Blast ensures Air Flow from ALL Sides ; Top, Bottom & Both Sides. Such equal Air Blast ensures Uniform Cooling of entire Bars thereby ensuring Uniform Mechanical Properties from end to end.
AIR QUENCHING FACILITY
EXCELLENT QUALITY HOT TOP OF GSSL INGOTS
BAD QUALITY HOT TOP GENERALLY FOUND IN THE STEEL INDUSTRY
The quality of forgings depends upon the quality of ingots. One of the parameters for Quality Ingots is the hot top quality. Ingot quality in terms of pipe, inclusions, centre looseness, and internal soundness in general is decided by the hot top quality. At GSSL a specially developed High Insulating Hot Top & Anti Piping Compound together with the excellent teeming practice has successfully resulted in production of very good quality of hot tops of ingots. Apart from the quality of steel, this has increased the yield by 3%.
Very clean steels are produced at GSSL by Innovative processes like 100% primary slag removal, Proper slag basicity with high inclusion absorption capacity, excellent de-oxidation, effective vacuum degassing, proper soft rinsing, well designed argon shroud, excellent teeming practice etc. Such steels are in great demand in Oil & Gas field, Nuclear Industry, Forging quality steels, Tool Steels, stainless steels for better performance and good life of the components
CUSTOMER”S SPECIFICATION | AISI 4140 | ACTUAL INCLUSION RATING OF GSSL STEEL | ||||
---|---|---|---|---|---|---|
Thin | Heavy | Thin | Heavy | |||
A | 1.50 | 1.0 | A | 0.50 | 0.50 | |
B | 1.50 | 1.0 | B | 0.50 | Nil | |
C | 1.50 | 1.0 | C | Nil | Nil | |
D | 1.50 | 1.0 | D | 1.0 | 0.50 |
1. Thermal mapping of the furnaces have been done and uniform temperature profiles in the furnaces have been achieved
2. Transferred time from opening of the furnace door to quenching has been reduced to < 60 secs
3. Vigorous agitation of the quenching medium and effective design of the cooling tower has resulted in quenching medium temperature < 50⁰ C
4. All these have resulted in very close control of the mechanical properties like UTS, YS, E%, RA% and Impact values
Specially designed, indigenously developed, “on shop floor”, hardness testing machine for checking hardness on full Length & @360 degree surface for sizes upto 600 mm.
HARDNESS TESTING
Water Quenching for DIN 1.2714 ; uniform in hardness across length & across section. DIN 1.2714 grade is an Oil Quench Grade Steel. Most Mills in India & All over World carry out Oil / Polymer quench. At Goradia, we have developed a very Special Water Quench process ensuring Uniformity in Hardness in entire length & across section even in large cross sections.
WATER QUENCHING
1. 300 series(SS 304 L / SS 316 L ) with oxygen up to 10ppm max & Micro cleanliness (micro inclusions) up to ABCD : 4 max
2. SS 410/SS420/SS431/SS416/F91/F6NM/F92; Nitrogen Control; 100 ppm max
3. Duplex & Super Duplex; with Nitrogen Content up to 3000 ppm
VOD REFINE