Expanding Technological Capabilities of The Combined Hardening of Steel by Deformation

Abstract

The technology of wave deformation hardening of metal machine parts is described, which allows obtaining a hardened surface layer up to 10 mm deep. The article presents the results of studying the microstructure and hardness of the samples strengthened as a result of chemical heat treatment and combined hardening consisting of preliminary wave deformation hardening and subsequent chemical heat treatment of structural alloyed steel 15CrС2Ni2Mg. It is established that a preliminary impact on the cemented material by a deformation wave contributes to creating uniformly high packing density of martensite, as well as smaller sizes of martensite needles in the subsurface layer and at the border of the cemented layer, in the core of the sample and contributes to the absence of large-needle martensite. Applying this technology allows forming a high uniform hardness at 65 HRC at a depth of 1.5 mm, with its gradual reduction to the core of the sample, while maintaining a high level of toughness. The results obtained allow recommending wave deformation hardening and the combined technology based on it to improve the performance properties of variable machine parts that operate under the conditions of sliding friction and impact loads.

Heatproof Relaxation of Welding Stresses Openwork Designs of Large Size Ultrasonic Field

“…When welding low-carbon steel ST3sp, wire electrode Sv-08GS : C≤ 0.10 %, Si 0.60-0.85%, Mn 1.40-1.70%, P ≤ 0.030%, S ≤ 0.025%, Ni ≤ 0.025%, Cr ≤ 0.020%, Cu ≤ 0.025%, welding current 120-130A, wire electrode diameter D = 1.2 mm Sv-08GS GOST 2241-80. [8][9][10][11][12][13][14][15][16][17][18][19][20] For laboratory research, a methodology has been developed for assessing the influence of ultrasonic relaxation technology of residual stresses on changing dimensional accuracybillet nonrigid workpieces. Laboratory plant for ultrasonic relaxation of residual stresses is presented in Figure 2.…”

Investigation of abrasive wear after combined hardening by deformation wave and heat treatment

“…The most common way to increase the hardness of metallic materials is hardening by heat treatment (HT). Recently, combined methods of hardening treatment have proved to be quite effective, especially combining the different nature of physical impact on the metal material being strengthened [1][2][3][4][5]. Thus, the use of preliminary hardening by surface plastic deformation (SPD), in particular, wave strain hardening (WSH), before HT, makes it possible to further increase the hardness of the metal material being hardened with a slight loss of impact strength [6].…”