Sintokogio, Ltd.

Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Yuji Kobayashi

Akinori Matsui

Takuya Koyama

Kyoichi Iwata

Toshiya Tsuji

Yutaka Neishi

Takashi Kano

Hidekazu Sueno

Manabu Enoki

Kiyoshi Okumura

Takeyoshi Nakata

Yuta Saito

Takanari Hamada

Hideaki Sugiura

Ryohei Ishikura

Makio Kato

Satoru Ujihashi

A metal material other than strain-free iron powder can be used as a reference piece for X-ray measurement of residual stress. The metal material is manufactured by nanocrystallizing at least a portion of a surface of a metal material, and then removing inherent strain by annealing the metal material, thereby eliminating stress.

Method for manufacturing reference piece for x-ray measurement of residual stress and reference piece for x-ray measurement of residual stress

A processing method according to one aspect incudes preparing a metal workpiece having a hole that opens to a surface thereof, filling the hole with processing media, and applying an external force to the processing media to apply a compressive residual stress to an inner surface of the hole.

Processing method and processing apparatus for workpiece

A test system includes a computer, a 3D printer, and a test device. The computer obtains shape data which indicates a three-dimensional shape of a workpiece and material data which indicates a material of the workpiece. The 3D printer forms a structural object which has a three-dimensional shape that is indicated by the shape data. The test device performs a test on a pseudo workpiece which has been prepared by adding, to the structural object, a test piece made of the material that is indicated in the material data.

Test system and test method

A shot peening method is disclosed. One method includes performing a first shot peening for applying residual stress to a surface of an object formed of a metal material at a first depth, and performing a second shot peening for applying residual stress to the surface of the object at a second depth deeper than the first depth after the first shot peening. The first shot peening is performed before the object is used at a high temperature and the second shot peening is performed after the object is used at the high temperature, and after a cracking caused by stress due to thermal expansion and contraction of crystal grains occurs in the object. The cracking being deeper than the first depth and shallower than the second depth.

Shot peening method

A deterioration evaluation method includes a determination step of determining a shot peening condition for imparting a maximum residual stress to an object formed of a metal material; a first shot peening step of performing first shot peening on the object under the shot peening condition; a first measurement step of measuring a first residual stress of the object after the first shot peening step; a second shot peening step of performing second shot peening on the object after the first measurement step under the shot peening condition; a second measurement step of measuring a second residual stress of the object after the second shot peening step; and an evaluation step of evaluating deterioration of the object based on the first residual stress and the second residual stress.

Deterioration evaluation method

A surface treatment processing method includes: a shot processing step of performing shot processing of shooting shot media at a treatment target; a first inspection step of nondestructively inspecting at least one of a surface side state and an external dimension of the treatment target subjected to the shot processing, evaluating that the treatment target is passed when an inspection result is within a first normal range set in advance, evaluating that the treatment target is failed when the inspection result is out of a first allowable range set in advance to include the first normal range, and evaluating that the treatment target is to be additionally processed when the inspection result is out of the first normal range but within the first allowable range; and an additional processing step of performing the shot processing again on the treatment target which is evaluated to be additionally processed.

Surface treatment processing method and surface treatment processing device

A first inspection step nondestructively inspects a surface side state of a treatment target to be subjected to shot processing of shooting shot media at the treatment target and evaluates that the treatment target is failed when an inspection result deviates from a first allowable range predetermined. A condition setting step sets a shot processing condition in response to the inspection result of the first inspection step for the treatment target evaluated as not failed in the first inspection step. A shot processing step performs shot processing of shooting shot media at the treatment target evaluated as not failed in the first inspection step in the shot processing condition set in the condition setting step. A second inspection step after the shot processing step nondestructively inspects a surface side state of the treatment target.

An apparatus includes an X-ray generating source; a first detecting element adapted to detect intensity of diffracted X-rays of the measuring object at a first detecting position; a second detecting element adapted to detect intensity of the diffracted X-rays of the measuring object at a second detecting position; a moving mechanism adapted to move each of the first detecting element and the second detecting element along a straight line extending in a direction orthogonal to a direction of incidence of the X-rays; a movement control unit adapted to control respective detecting positions of the first detecting element and the second detecting element by driving the moving mechanism; and a stress calculation unit adapted to calculate residual stress of the measuring object based on intensity peaks of the diffracted X-rays detected, respectively, by the first detecting element and the second detecting element each moved by the moving mechanism.

Residual stress measuring apparatus and residual stress measuring method

First, it is determined in a determination step by a determination unit whether there is a nitrided layer on a surface of a water-cooled hole of a mold, by using an eddy current sensor. Next, in a shot step, when it is determined in the determination step that there is no nitrided layer, the surface of the water-cooled hole of the mold is shot-peened under a shot condition set according to a base material of the mold, and when it is determined in the determination step that there is the nitrided layer, the surface of the water-cooled hole of the mold is shot-peened under a shot condition which maintains a state where there is the nitrided layer.

In a trial peening step, a shot peening process is applied to a back faceB of a moldin which an opening of a closed-end water cooling holeis formed. Next, in an evaluation step, compressive residual stress and surface roughness of a region shot-peened in the trial peening step are measured and an extent of shot peening treatment in the trial peening step is evaluated based on measurement results. Next, in a peening step, a surface of the water cooling holein the moldis shot-peened under peening conditions set based on peening conditions for the trial peening step and on evaluation results produced in the evaluation step.

Shot peening method, shot peening evaluation method, and shot peening evaluation assembly structure

A method of evaluating impact force input to a workpiece member with a laser irradiated in laser peening processing is provided. This evaluation method includes a signal acquiring step, an input function calculating step, and an evaluating step. In the signal acquiring step, a detected waveform is acquired. The detected waveform is output during the laser peening processing by an AE sensor that detects an elastic wave generated in the workpiece member. In the input function calculating step, an input function I(t) by laser irradiation is calculated. In the evaluating step, impact force is evaluated using the input function I(t) by the laser irradiation.

Evaluation method and evaluation system for impact force of laser irradiation during laser peening and laser peening method and laser peening system

First, a nozzle insertion process in which a nozzle is inserted into a water cooling hole having a small diameter which is provided in a back of a mold is performed. Then, an injection process in which a mixed flow of air having a pressure ranging from 0.1 MPa to 1.0 MPa with an injection particle is jetted from a leading end of a nozzle to a distal portion of the water cooling hole. As a result, a shot peening process is performed on the distal portion of the water cooling hole.

Shot processing method and shot processing device

The cost for shot-peening is intended to be reduced. The method for shot-peening of the present invention comprises a first step for processing a work by shot-peening by projecting shots onto the work, and a second step for processing the work by shot-peening by projecting the shots onto the work at a speed for projecting the shots that is slower than the speed in the first step, wherein the second step uses the same shot-peening machine and same shots that have been used in the first step. By this method, an intended distribution of compressive residual stresses is obtained by the processes in the first and second steps and the surface roughness of the work is decreased by the process in the second step wherein the shots are projected at the speed that is slower than that in the first step. Further, no removal or supply of the shots and no re-setting of the conditions for the process that are related to the removal and supply of the shots are required. Multiple shot-peening machines do not need to be installed. Thus the cost for shot-peening is reduced.

Method for shot-peening and a shot-peening machine

The present invention aims to provide a method of shot-peening treatment that substantially improves the durability (particularly, heat check resistance) of the treated surface of the steel products in the process of treating by shot peening (hereafter, 'SP') the surface of the steel product that is the work to be treated and that was treated by heat hardening. The SP treatment of the present invention that gives the SP treatment to the steel product that was heat-treated and that is a work to be treated comprises the first SP treatment that removes the compound layer (white layer) and a second SP treatment that gives compressive residual stress to the first SP treated surface that was treated by the first SP treatment where the second SP treatment is carried out only to the products where it has been proved by the non-destructive inspection that the compound layers are removed by the first SP treatment.

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Toyokawa, Japan

Yuji Kobayashi