6 results about "Tempering" patented technology

Disclosed is a heat treatment process for lowering the yield ratio of ultra-high-strength marine steel. Critical temperature quenching and high temperature short time tempering are adopted to obtain the low-yield-ratio ultra-high-strength marine steel, that is to say, the quenching temperature is Ac3+/-20 DEG C, the heat preservation time for quenching is 1.4-1.8 min/mm, the tempering temperature is Acl-(80-150) DEG C, and the heat preservation time for tempering is 0.5-2.0 min/mm. According to the heat treatment process, under the circumstance that matching of the strength and toughness of a steel plate is ensured, the yield ratio of the ultra-high-strength marine steel is significantly lowered, thereby completely meeting the requirements of a ship structure, an ocean platform, etc. which need the ultra-high-strength marine steel of the 420 MPa-690 MPa level or above the 690 MPa level.

The invention discloses a curved glass flexible shaft bending tempering forming method. When in production of the curved glass, after the glass is discharged from a heating furnace, the glass is preformed in the trend that the two side parts in the transverse direction are kept on the same plane and the middle part in the transverse direction gradually sinks along the conveying direction, then enters a forming and toughening section under the condition that the two side parts in the transverse direction are supported, and is finally formed and toughened to finish the bending and toughening manufacturing of the curved glass. After the method is adopted, when the glass gradually becomes arc and enters the forming tempering section, the flexible shaft roller ways are always arranged at the two side parts of the glass in the transverse direction to be used as supports, and the edge parts are not suspended, so that the wave bending phenomenon of the edge parts is eliminated.

The invention discloses a large-diameter medium-carbon low-alloy wear-resistant steel ball. The large-diameter medium-carbon low-alloy wear-resistant steel ball comprises the following raw materials of, in percentage by weight, 0.4% to 0.5% of C, 0.8% to 1.0% of Cr, 0.5% to 0.7% of Mn, 1.2% to 1.4% of Si, 0.1% to 0.2% of Ni, 0.001% to 0.002% of B, 0.06% to 0.07% of Nb, P less than or equal to 0.05%, S less than or equal to 0.05% and the balance Fe and inevitable impurities. The invention further discloses a preparation method of the large-diameter medium-carbon low-alloy wear-resistant steel ball. The preparation method comprises the following steps that S1, raw materials such as the alloy in the claim 1 or 2 are smelted and cast into a continuous casting billet; and S2, the continuous casting billet is heated and then rolled into a steel ball, air cooling is carried out, then heating and heat preservation are carried out, quenching, tempering and natural cooling are carried out, and the large-diameter medium-carbon low-alloy wear-resistant steel ball is obtained. The steel ball is large in diameter and has good hardness and impact toughness.

The invention discloses a high-stability die steel surface combined dual-treatment technology. A workpiece is quenched in a salt bath furnace, the temperature of a salt bath is close to the martensite transformation starting point, the workpiece stays at the temperature for 2min to 5min, then the workpiece is taken out to be subjected to air cooling, the purpose of grading air cooling is to enable the temperature of the interior and the exterior of the workpiece to be relatively uniform, martensite transformation is carried out at the same time, the quenching stress can be greatly reduced, and deformation and cracking are prevented. The invention relates to the high-stability die steel surface combined dual-treatment technology, grading quenching and secondary tempering are conducted on steel with the proper temperature and time control, and therefore the steel can be good in toughness and high in strength; and meanwhile, a nitriding layer and a hard film are tightly combined and generated on the surface of a workpiece by adopting a manner of the cooperation of co-permeation oxidation and ionization deposition, compared with single ionization deposition and co-permeation processing, better combination and protection effects can be achieved, the stress distribution continuity of the film layer and the nitriding layer is good, the bearing capacity of the steel to a hard film is improved, and the hard film is prevented from falling off due to the stress.

The invention discloses S460QLO thick plates used for offshore weldable structures and a production method, and relates to the technical field of steel production. The S460QLO thick plates used for the offshore weldable structures comprise the following chemical components in percentage by mass: 0.06%-0.08% of C, 1.40%-1.70% of Mn, 0.10%-0.30% of Si, smaller than or equal to 0.015% of P, smaller than or equal to 0.003% of S, 0.020%-0.040% of Nb, smaller than or equal to 0.020% of Ti, 0.020%-0.055% of Alt, 0.10%-0.25% of Cr, 0.30%-0.50% of Ni, smaller than or equal to 0.006% of N, smaller thanor equal to 0.42% of CEV, smaller than or equal to 0.20% of Pcm and the balance Fe and inevitable impurities. Offline quenching is replaced by an online quenching technology, and steel plates subjected to rolling can be directly subjected to tempering production, so that the low-temperature toughness of the middle portions, in thickness directions, of the steel plates is greatly improved.

The invention relates to the technical field of GCr15 heat treatment processes, in particular to a GCr15 heat treatment process. The GCr15 heat treatment process is used for steel parts made of GCr15.The GCr15 heat treatment process comprises the following steps that 100, a steel part is heated to the austenite temperature through induction heating equipment to be subjected to quenching heating treatment; 200, quenching cooling treatment is carried out on the steel part subjected to the quenching heating treatment through induction cooling equipment; 300, tempering heating treatment is carried out on the steel part subjected to the quenching cooling treatment through the induction heating equipment; and 400, natural cooling is carried out on the steel part subjected to the tempering heating treatment. A single induction heating process and a single temperature control cooling process are adopted for the steel part, and multi-section quenching heating and tempering heating treatment are adopted in the treatment process, so that a produced steel part is small in hardness scatter difference, tiny in deformation and small in turning amount, and energy consumption is low while the efficiency is guaranteed.