Hot & Cold Carbon, Alloy & Stainless Steel Plant

HMT HFS Unit has been commenced and commissioned with state-of-the-art manufacturing process of cross roll piercing, accu roiling, SRM technology In Dec 2011 and produces various carbon, alloy and stainless steel grades of seamless tubular products. Cross roll piercing process begins with piercing of a hot round bar cut piece on the piercer, followed by accu roll for precision dimensional control of intermediate product, hollow cylindrical shell. Finally, the dimensions are controlled within specified variations on the stretch reducing miII (SRM). This process ensures better control over wall thickness variations as compared to other manufacturing process.

HMT manufactures specialized tubes for various mechanical applications in Boilers and Boiler components, Economizers, Heat Exchangers and pipes used for cryogenic applications. These items can be customized to the requirement of individual customers in terms of heat treatment end end finishes.

HMT has introduced 4 pilger mill and 2 heavy duty draw bench in Unit 3 with annual production capacity of 12000MT p.a. to manufacture mechanical, hydraulic, boiler tubes, etc. This multistep forming process guarantees high quality seamless tubes. This process greatly improves materials grain structure & due to multi step reduction process from larger diameter tube to smaller diameter tube yields excellent outside & inside surface and closed eccentricity quality tubes.

Process

The hot finish seamless carbon steel & alloy steel division is equipped with latest machineries and all processes are fully automatic with on line ultrasonic & eddy current testing & latest testing facilities for chemical & mechanical testing to meet the customer requirements.

CROSS-ROLL PIERCING-ACCU ROLLING - SRM TECHNOLOGY FOR HFS-HMT UNIT-III

This is the state-of-the-art manufacturing process for high quality seamless pipes and tubes. All the operational points of manufacturing involves through closely monitored and professionally executed, to meet the requirements of clients and various third party inspection agencies. The raw material steel round bars selected for HFS tubular products are ensured within the framework of our stringent internal TDC encompassing the specific requirement mentioned In P.O. conforming to the highest quality standard.

This process begins with heating of round bars steel between temperature range 1150-1250°C in a rotary hearth furnace which passes through a cross-roll piercing mill where solid round bar steel is converted into cylindrical elongated hollow shells. These hollow shells are passed through accu roll mill governed by two guided disk monitored by power pack system where high precision mandrel inside the hollow moves along with pipe during rolling, which ensures of maintaining precision dimensional variation, smooth inside surface finish of elongated shells. These hollow shells are re heated at 900 to 950°C prior to passing through 24 stand SRM (Stretch Reducing Mill) where final size, dimension and surface finish of HFS tubular product is achieved. Finished tubes / pipes undergo various testing as per the specification / customer’s requirements followed by marking and dispatch.

MANUFACTURING RANGE	OD : 4 mm to 220 mm THK : 0.5 mm to 25 mm Length : Upto 31 Meters depending up on size
GRADE & SPECIFICATIONS	ASTM/ASME A/SA 179, 192, 199, 106/53 (Gr. A, B, C), 210 (Gr. A1, C), A 519, 213 (Gr. T1, T2, T5, T9, T91, T11, T12,T22), 335 (Gr. P1, P2, P5, P9, P91, P11, P12, P22), 334/333(Gr. 1, 3, 8, 6), 209 (Gr. T1, T1A, T1B), 556 (Gr. A, B, C) etc.DIN 17175/2391 (Gr. St35.8, St45.8, St 52, 16 Mo3, 13CrMo44,10CrMo910), 2448, 1630, BS 3059, 980, 6323, 3602/1,EN10716-2, 4130, EN 18, P235, P275, P355,1026, 1030 etc.
CAPACITY	75,000 MTPA Other specification / Grades can be supplied as per customer's requirements

Hot & Cold Carbon, Alloy & Stainless Steel Plant

Process

Flow Chart